METHOD FOR IMPROVING THE TASTE OF MORINGA SEEDS WHILE RETAINING THEIR NUTRITIVE VALUE

Abstract

A method for treating Moringa seeds is disclosed. A starting material comprising ground Moringa seeds, preferably seeds that have undergone a process to remove their oil, is contacted with water. The water is drained, and the Moringa seeds are then contacted with water a second time. The product may then be dried or passed to an extruder. The process almost completely removes the unpleasant bitter taste associated with Moringa seeds, but retains most of the protein content of the starting material. In contrast to methods known in the art, the method does not require adjustment of the pH or the use of any organic solvent. A composition comprising ground Moringa seeds that comprises at least 30% protein and has a glucosinolate concentration <10% of that of naturally-occurring Moringa seeds, while lacking the bitter taste associated with raw Moringa seeds, is also disclosed.

Claims

1-55. (canceled)

56. A method for treating Moringa seeds, said method comprising: obtaining a starting material comprising a material selected from the group consisting of ground Moringa seeds, ground germinated Moringa seeds, and ground fermented Moringa seeds; contacting said starting material with a first quantity of water for a first predetermined period of time, thereby producing a soaked Moringa seed material; separating at least partially said soaked Moringa seed material from said water; contacting said soaked Moringa seed material with a second quantity of water for a second predetermined period of time, thereby producing debittered Moringa seed material; and, separating at least partially said debittered Moringa seed material from said water; wherein said method does not comprise any step requiring use of organic solvent.

57. The method according to claim 56, wherein said starting material comprises ground Moringa seeds that have undergone a process to remove oil at least partially from said Moringa seeds.

58. The method according to claim 57, wherein said starting material comprises milled de-oiled Moringa seed cake.

59. The method according to claim 56, wherein at least one of the following conditions is met: (a) said step of contacting said starting material with a first quantity of water comprises: placing said starting material in a vessel; adding an excess of water to said vessel; and, allowing said starting material and said first quantity of water to remain in said vessel for said first predetermined period of time; and, (b) said step of contacting said soaked Moringa seed material with a second quantity of water comprises: placing said soaked Moringa seed material in a vessel; adding an excess of water to said vessel; and, allowing said soaked Moringa seed material and said second quantity of water to remain in said vessel for said second predetermined period of time.

60. The method according to claim 59, wherein: said step of contacting said starting material with a first quantity of water comprises mixing or stirring said starting material and said first quantity of water during said first predetermined period of time; and, said step of contacting said soaked Moringa seed material with said second quantity of water comprises mixing or stirring said soaked Moringa seed material and said second quantity of water during said second predetermined period of time.

61. The method according to claim 56, wherein at least one of the following conditions is met: said first predetermined period of time is between 30 and 90 minutes; and, second predetermined period of time is between 5 and 15 minutes.

62. The method according to claim 56, wherein at least one of the following conditions is met: said step of contacting said starting material with a first quantity of water comprises contacting said starting material with sufficient water to provide a water:starting material weight ratio of between 3 and 20; and, said step of contacting said soaked Moringa seed material with a second quantity of water comprises contacting said soaked Moringa seed material with sufficient water to provide a water:starting material weight ratio of between 3 and 20.

63. The method according to claim 56, wherein at least one of said steps of contacting said starting material with a first quantity of water and contacting said soaked Moringa seed material with a second quantity of water comprises contacting with water, the pH of which has been adjusted to be other than 7.

64. The method according to claim 56, wherein at least one of said steps of contacting said starting material with a first quantity of water and contacting said soaked Moringa seed material with a second quantity of water comprises contacting with water characterized by a temperature selected from the group consisting of room temperature; <10° C.; and between 85° C. and 99° C.

65. The method according to claim 56, wherein said step of separating at least partially said soaked Moringa seed material from said water is performed by a method selected from the group consisting of filtering, decanting, and centrifuging.

66. The method according to claim 56, wherein said step of contacting said soaked Moringa with said second quantity of water comprises rinsing said soaked Moringa seed material.

67. The method according to claim 66, wherein said step of rinsing said soaked Moringa seed material is preceded by a step of placing said step of placing said soaked Moringa seed material on a filter.

68. The method according to claim 56, wherein said step of separating at least partially said debittered Moringa seed material from said water is performed by a method selected from the group consisting of filtering, decanting, and centrifuging.

69. The method according to claim 56, wherein said step of separating at least partially said debittered Moringa seed material from said water is followed by a step of drying said debittered Moringa seed material.

70. The method according to claim 56, wherein said step of separating at least partially said debittered Moringa seed material from said water is followed by a step of passing said debittered Moringa seed material to an extruder.

71. The method according to claim 56, wherein said method does not comprise any step of adjusting pH.

72. The method according to claim 56, wherein said water is tap water.

73. A composition comprising Moringa seed material, said composition derived from a starting material selected from the group consisting of ground Moringa seeds, ground germinated Moringa seeds, and ground fermented Moringa seeds; said composition comprising at least 30% protein (w/w) and 18%-55% fiber, wherein: said composition comprises a glucomoringin concentration that is less than 30% (w/w) of that of said starting material; and, said composition has not been produced by any process involving contact with organic solvent.

74. The composition according to claim 73, wherein said composition is characterized by at least one of the following characteristics: said composition has a glucomoringin concentration that is less than 5% (w/w) of that of said starting material; said composition has a glucosinolate concentration that is less than 30% (w/w) of that of said starting material; said composition comprises at least 40% protein; said composition comprises 30-60% (w/w) protein; said composition comprises 20-60% (w/w) protein (dry basis); said composition comprises 0.5-16% (w/w) fat; said composition comprises 15-40% (w/w) soluble fiber; said composition comprises 0.5-3.5% (w/w) sugar; said composition comprises 2-3% (w/w) ash; and, said composition is characterized by a loss on drying of 1-10% (w/w).

75. The composition according to claim 73, wherein said composition is characterized by a characteristic selected from the group consisting of: said composition comprises proteins having molecular weights, as determined by SDS-PAGE electrophoresis with Coomassie staining, of 43.7±1.3 kDa, 32.9±1.0 kDa, 30.4±0.9 kDa, 19.7±0.5 kDa, and 6±1 kDa; said composition comprises proteins having molecular weights, as determined by SDS-PAGE electrophoresis with Coomassie staining, of 43.7±1.3 kDa, 32.9±1.0 kDa, 30.4±0.9 kDa, 19.7±0.5 kDa, and 6±1 kDa; and, said composition comprises proteins having molecular weights identical to within one standard deviation of molecular weights of proteins of said starting material, as determined by SDS-PAGE electrophoresis with Coomassie staining.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0073] The invention will now be described with reference to the figures, wherein:

[0074] FIG. 1 shows the general glucosinolate structural formula (FIG. 1A) and structural formulas of three typical gluconsinolates: glucotropaeolin (FIG. 1B), glucosoonjnain (FIG. 1C), and glucomoringin (FIG. 1D);

[0075] FIG. 2 shows HPLC-MS chromatograms that show the peak corresponding to glucomorinigin in samples of Moringa before and after treatment according to the method disclosed herein; and,

[0076] FIG. 3 shows SDS-PAGE electrophoresis gels comparing the protein compositions of raw Moringa seeds and Moringa seed material after treatment by the process disclosed herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0077] In the following description, various aspects of the invention will be described. For the purposes of explanation, specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent to one skilled in the art that there are other embodiments of the invention that differ in details without affecting the essential nature thereof. Therefore, the invention is not limited by that which is illustrated in the figures and described explicitly in the specification, but only as indicated in the accompanying claims, with the proper scope determined only by the broadest interpretation of said claims. In some cases, for clarity or conciseness, individual elements of the invention are discussed separately. Nonetheless, any combination of elements of the invention that is not self-contradictory is considered by the inventors to be within the scope of the invention.

[0078] Some embodiments of the invention are described as “comprising” a set of components or method steps, i.e. the scope of the invention may include embodiments that include components or method steps in addition to those explicitly listed. In all cases in which an embodiment is described as “comprising” a set of components or method steps, the scope of invention is to be understood to include embodiments in which the invention “consists of” the listed components or method steps, i.e. embodiments that include the listed components or method steps and no others, and embodiments in which the invention “consists essentially of” the listed components or method steps, i.e. embodiments that do not include any components or method steps not listed that would materially affect the basic and novel characteristics of the invention.

[0079] Unless otherwise specified, as used herein, the term “Moringa” is used to refer to any plant of genus Moringa.

[0080] Unless otherwise specified, when the term “Moringa seeds” is used generically, it is used to refer to Moringa seeds without reference to the amount or type of processing they may have undergone prior to their treatment by the method disclosed herein. Unless otherwise specified, the term “Moringa seed material” refers to a material made of processed Moringa seeds without specific reference to the processing that they have undergone.

[0081] Unless otherwise specified, with reference to numerical quantities, the term “about” refers to a range of ±20% about the nominal value.

[0082] Unless otherwise specified, as used herein, the term “excess” with respect to the relative amounts two materials refers to a mass excess.

[0083] As used herein, the abbreviation “PP” stands for “polypropylene.”

[0084] Unless otherwise specified, as used herein, the term “protein content” refers to the total amount of protein (e.g. percentage by weight) in a sample, without reference to the specific proteins or amino acids present in the sample.

[0085] Unless otherwise specified, the terms “defatted” and “de-oiled” used interchangeably to describe Moringa seeds that have undergone a process to remove at least partially their oil or fat content.

[0086] Unless otherwise specified, reported protein concentrations are obtained from the amount of nitrogen in the sample as determined by the Kjehldahl method. Total Kjehldahl Nitrogen (TKN) is used as a proxy for protein content, and the reported protein concentrations represent TKN multiplied by a standard constant factor of 6.25.

[0087] As used herein, the term “soaked Moringa seed material” refers to Moringa seeds or processed Moringa seeds that have undergone a step of contact with water, whether that step comprises quiescent contact with water or active contact, e.g. contact under conditions of stirring or mixing.

[0088] The instant invention provides a novel method for treating Moringa seeds that removes the bitter taste and unpleasant aftertaste of the seeds while retaining most of the protein content that characterizes Moringa. The inventors have discovered, surprisingly, that removal of the bitter taste of Moringa seeds is possible in which the only material used to treat the seeds is water. The novel method does not incorporate any step in which an organic solvent is used, and in preferred embodiments of the invention, the process takes place without any step that requires treatment at a specific pH in particular or under specifically basic or acidic conditions in general.

[0089] A novel Moringa seed composition that contains at least 30% protein by weight and from which the bitter taste of unprocessed Moringa seed has been removed is also disclosed herein.

[0090] In the description that follows, the process and product are described in terms of the use of Moringa seeds as the starting material. While in some embodiments, Moringa seeds are used, embodiments in which the starting material comprises germinated Moringa seeds and/or fermented Moringa seeds in addition to or instead of Moringa seeds are considered by the inventors to be within the scope of the invention.

[0091] In preferred embodiments of the method disclosed herein, ground Moringa seeds are used in the starting material, as they provide better results than whole Moringa seeds. In more preferred embodiments of the method, the Moringa seeds are dehulled prior to grinding. In particularly preferred embodiments of the invention, the starting material comprises ground Moringa seeds that have undergone a process that extracts at least part of their oil (“defatted Moringa seeds”). A non-limiting embodiment of such a process is cold pressing. In preferred embodiments of the invention in which the starting material comprises defatted Moringa seeds, the process of defatting does not involve the use of any organic solvent. The oil itself is tasteless, and the starting material retains the bitter taste of untreated Moringa seeds; thus, it is not essential to remove all of the oil. In preferred embodiments of the invention, the starting material is ground Moringa seed cake made from seed material that remains after commercial oil extraction, i.e. after all of the oil that can be extracted economically has been removed.

[0092] The starting material is contacted with water, e.g. by placing the starting material in an appropriate receptacle, adding water, and allowing the seeds to soak for a predetermined length of time, preferably with stirring. Any source of water appropriate for use with food may be used. A non-limiting example is tap water. In typical embodiments of the invention, sufficient water is added to create a slurry. In preferred embodiments of the invention, water is added to the starting material in a volume ratio of between 2:1 and 20:1. In especially preferred embodiments of the invention, water is added to the starting material in a volume ratio of about 4:1. In some embodiments of the invention, the water is at room temperature (typically about 20-25° C.). In some embodiments of the invention, cold water, typically at a temperature of less than 10° C. and preferably at a temperature of about 4° C., is used. In some embodiments of the invention, warm water, typically at a temperature of about 40° C., is used. In some embodiments of the invention, hot water, typically at a temperature between 88° C. and 97° C. and preferably at a temperature of between 90° C. and 93° C., is used.

[0093] In preferred embodiments of the invention, the step of contacting the starting material with excess water is performed by adding the water to the starting material in an appropriate receptacle and then mixing continuously for 30-90 minutes.

[0094] After the starting material has contacted the water, the soaked Moringa seed material is separated from the water. Any method known in the art can be used to separate the water from the soaked Moringa seed material; non-limiting examples include filtration, decanting, and centrifuging. The separation need not be complete; in typical embodiments of the invention, the soaked Moringa seed material is still wet after the water has been separated.

[0095] In preferred embodiments of the invention, after separation of the water from the soaked Moringa seed material, the soaked Moringa seed material is then contacted a second time with water. In particularly preferred embodiments of the invention, an excess of water is used in this step as well. As in the first step of contact with water, any source of water suitable for use with food can be used. The second contact is generally shorter than the first one, and in typical embodiments comprises adding an excess of water to the soaked Moringa seed material and then mixing for 5-10 minutes. In some embodiments of the invention, the second contact comprises rinsing the Moringa seed material on an appropriate filter.

[0096] In some embodiments of the invention, after the second contact with water, the soaked Moringa seed material is dried, typically to a final water content of less than 8% by weight. In other embodiments of the invention, following the second contact with water, the soaked Moringa seed material is passed directly to an extruder. The extruded material can then be processed according to any method known in the art.

[0097] In preferred embodiments of the invention, the steps of contacting the Moringa seed material with water are performed using water as received from its source, i.e. at a pH of 7 and without any additives or processing. In some embodiments of the invention, at least one of the steps of contacting the starting material with water is performed under acidic or basic conditions, i.e. the pH of the water is adjusted prior to its contact with the Moringa seeds by addition of an acid or base that is compatible with and approved for use in food processing prior to the step of contact with the Moringa seed material. When neutral water is used in the steps of contacting the Moringa seed material with water, the pH of the supernatant liquid typically equilibrates at a value of 5-5.5. Thus, in some embodiments of the invention, at least one of the steps of contacting the Moringa seed material with water comprises contacting the Moringa seed material with water until the supernatant liquid has reached a pH of between 5 and 5.5.

[0098] While the method disclosed herein includes within its scope embodiments in which at least one of the steps of contacting the Moringa seed material is performed under acidic or basic conditions, it is emphasized that in contrast to methods known in the art (e.g. the method disclosed in '041), the method disclosed herein does not require any use of organic solvent or any step of pH adjustment at any point in the process; methods of protein extraction known in the art, such as the one disclosed in '041, require extraction of the protein under basic conditions followed by lowering of the pH to the protein's isoelectric point. Jain has shown that the extractability of protein from Moringa is not strongly pH-dependent. Without being bound by theory, it appears that not only is there no single pH at which the extraction of the protein from the raw starting material is most efficiently performed, but there is also no single isoelectric point that characterizes the Moringa proteins that would require adjustment of the pH in order to increase the efficiency of the separation of the proteinaceous material. As can be seen from the non-limiting examples presented below, contact and rinsing with water is sufficient to improve significantly the taste of Moringa, and in typical embodiments of the invention, approximately 50% of the protein of the Moringa starting material is retained in the product, independent of the pH to which the water is adjusted.

[0099] As the non-limiting examples given below demonstrate, not only does the method disclosed herein yield a product that has a protein content similar to that of the starting material, it also produces a product that is significantly more palatable than the starting material. As was explained above, it is widely believed that the bitter taste of Moringa is due to naturally-occurring glucosinolates. In order to assess the ability of the method disclosed herein to remove glucosinolates, HPLC-MS analyses were performed of a sample of Moringa as received and after treatment by the method disclosed herein. A milled defatted Moringa seed cake was treated according to the method disclosed herein, with the steps of contacting the Moringa with water performed using cold (˜4° C.) water. The analysis was performed with an Agilent Technologies Model 6550 Q-TOF LC/MS system. MS detection was performed with an ESI interface in negative mode, and LC detection with an Agilent Model 1290 UV detector operating at a detection wavelength of 229 nm. A KROMASIL 100-5-C18 250 mm×2.1 mm×5 μm column was used; the column temperature was 25° C., the sample temperature 20° C., and the flow rate of the mobile phase (acetonitrile/H.sub.2O+20 mM ammonium formate, run in gradient mode from 2% acetonitrile at t=0 to 50% acetonitrile from 30-40 min and then to 2% acetonitrile at t=42 min) was 0.3 ml/min.

[0100] Samples of the starting material and product of the process were prepared by placing ˜0.5 gin a 250 ml glass bottle, inserting a magnetic stirrer, adding 50 ml distilled water, mixing, and adding 50 ml methanol. The bottle was placed in a 70° C. oil bath and the contents stirred for 15 minutes. The sample was then removed from the oil bath and cooled for 10-15 min until undissolved material had precipitated. 1 ml of the supernatant was filtered through an 0.2 μm PTFE syringe filter, and 0.5 ml of the filtrate diluted with 0.5 ml of a 1:1 (v/v) water/methanol mixture. Following the completion of the treatment of the Moringa seeds, samples of the water that had been used to contact the Moringa seed material were prepared by adding 10 ml methanol to a ˜10 ml sample along with a magnetic stirrer. The sample was placed in a 70° C. oil bath and stirred for 15 minutes. The sample was then removed from the oil bath and cooled for 10-15 min until undissolved material had precipitated. 1 ml of the supernatant was filtered through an 0.2 μM PTFE syringe filter, and 0.06 ml of the filtrate diluted with 0.94 ml of a 1:1 (v/v) water/methanol mixture to produce a 33-fold dilution of the process liquid.

[0101] Reference is now made to FIG. 2, which shows LC chromatograms corresponding to the MS peak at 570 Da, assigned to the [M-H].sup.− peak of glucomoringin (FIG. 1D; MW=571). FIG. 2A shows the chromatogram of the starting material, FIG. 2B the chromatogram of the product of the treatment, and FIG. 2C the water used to contact the Moringa seed material, obtained following the conclusion of the treatment. As is clear from the chromatograms, the process disclosed herein removes >95% of the glucomoringin from the Moringa seeds, and transfers it to the water used to contact the Moringa seed material.

[0102] It is within the scope of the invention to disclose a Moringa seed composition that has a high protein content but that is considerably less bitter than unprocessed Moringa seeds. The Moringa seed composition includes no ingredients other than processed Moringa seeds and contains at least 30% protein by weight; in preferred embodiments, the composition contains at least 40% protein by weight. In some embodiments, the composition contains between 30% and 60% protein by weight. The composition is characterized by a glucosinolate concentration that is less than 10%, and in preferred embodiments, less than 5% of the glucosinolate concentration of the starting material, e.g. unprocessed (naturally occurring) Moringa seeds. In some embodiments, the composition comprises 0.5-16% fat by weight. In some embodiments, the composition comprises about 50% fiber by weight. In preferred embodiments, the composition comprises 15%-40% by weight soluble fiber and about 15% by weight insoluble fiber. In some embodiments, the composition comprises 0.5-3.5% sugar by weight. In some embodiments, the composition comprises 2-3% ash by weight. In some embodiments, the composition comprises 1-10% moisture by weight.

[0103] In preferred embodiments, the composition comprises Moringa seeds from which at least part of the oil has been extracted, preferably by a method that does not involve any contact of the Moringa seeds with organic solvent. As shown in the examples below, the composition is highly palatable. In typical embodiments, it has a bitterness of ≤2.5 on a scale in which 0 represents no taste at all and 5 represents extremely bitter. In preferred embodiments, it has a bitterness of ≤2. In more preferred embodiments, it has a bitterness of ≤1. In preferred embodiments, the composition is produced by the process disclosed herein.

[0104] After the completion of the treatment of the Moringa seeds, the water used in the treatment retains useful material such as extracted protein and glucosinolates that can be separated and recovered. As a non-limiting example, the protein can be recovered by ultrafiltration with a suitable membrane and then drying, e.g. on a spray dryer. The recovered protein can be used separately, or added to the product to increase its protein concentration. The glucosinolates and carbohydrates extracted from the Moringa seeds do not appear to degrade or decompose, and can also be separated from the water for further use.

[0105] The following examples are presented to assist a person of ordinary skill in the art to make and use the invention herein disclosed, and are not intended to be limiting in any way. In the examples, the seeds used in all cases were from Moringa oleifera. In cases in which the amounts of components are given as ranges, each range represents the range of results of independent analyses of the compositions a plurality of different samples. In cases in which more than result is reported in a given table, each result represents an independent experimental run.

[0106] Determination of the level of bitterness of samples was performed by a blind taste test in which unmarked samples were given to each member of a group of six individuals to taste. The members of the group rinsed their mouths with water following the tasting, and in cases in which the sample was judged to be extremely bitter, the next sample was not tasted until after the bitter taste had completely gone away. In some of the examples, the taste was rated on a scale of 0-5, in which 0 represents no bitter taste at all and 5 represents extremely bitter.

EXAMPLE 1

[0107] A sample of Moringa seeds was treated according to the method of Ogunsina and Radha. The Moringa seeds were then tasted and found to be extremely bitter.

EXAMPLE 2

[0108] A sample of defatted milled Moringa seeds as obtained. The starting material was analyzed and found to contain approximately 50% protein, 25% fiber, 10% fat, and 2% sugar by weight.

[0109] 1.9 kg of the starting material was mixed with 7.7 kg tap water that had been heated to ˜93° C. The resulting slurry was had a pH of —5.4. The slurry was mixed in a stirrer for 45 minutes under heating to 93-98° C. The slurry was then filtered on a 20 μm PP filter cloth. An additional 7.7 kg of tap water that had been heated to ˜92° C. was added to the wet solids and stirred for an additional 5-10 minutes followed by filtration. The resulting wet cake, weighing ˜3.6 kg, was dried in a vacuum oven dryer at 70° C. and a pressure of 20-50 mbar.

[0110] The dry product weighed ˜1 kg and was found to contain approximately 39% protein, 53% fiber, 1.5% fat, and 1.5% sugar, with improved taste.

EXAMPLE 3

[0111] Moringa seeds milled after oil extraction were obtained. The milled seeds were analyzed and found to contain ˜50% protein, ˜25% fiber, and ˜10% fat.

[0112] 1 kg of the Moringa seeds was mixed with 4 kg of cold tap water (˜4° C.). A sufficient quantity of a 10% (w/v) aqueous solution of NaOH was added to raise the pH to 9. The mixture was kept at 4° C. for 15 minutes under continuous mixing. A sufficient quantity of an 8% (w/v) aqueous solution of HCl was added to lower the pH to 4. The mixture was then kept at 4° C. for 1 hour under continuous mixing, followed by filtration on a 20 μm PP filter cloth. 4 kg of room-temperature tap water was added to the wet solids retained after filtration, and the resulting slurry mixed for an additional hour followed by filtration. The wet solids remaining after the second filtration were then dried in a vacuum oven at 70° C. under a pressure of 20-50 mbar. After drying, ˜0.45 kg of a dry powder was obtained.

[0113] The powder contained ˜36% protein by weight, and had an improved taste relative to the starting material.

EXAMPLE 4

[0114] Milled Moringa seeds containing 45-55% proteins, 4-13% fat, 15-22% soluble fiber, 8-14% insoluble fiber, 3.5-7% sugar, 4-6% ash, and 6-9% moisture were obtained.

[0115] 1 kg of the milled seed cake was mixed with 4 kg room temperature tap water. A sufficient quantity of a 10% (w/v) aqueous NaOH solution was added to raise the pH to 9. The mixture was mixed at room temperature for 15 minutes. A sufficient quantity of an 8% (w/v) aqueous HCl solution to lower the pH to 4 was then added. The resulting mixture was then mixed for 1 hour at room temperature, followed by filtration on a PP filter cloth. The wet solids retained after filtration were washed with additional tap water, and then dried in a vacuum drying oven at 70° C. and a pressure of 20-25 mbar. After drying, ˜0.45 of a dry powder was obtained.

[0116] The powder contained by weight 30-45% protein, 0.5-1.5% fat, 35-40% soluble fiber, 15% insoluble fiber, 0.5-2% sugar, 2-3% ash, and 3-7% moisture. The bitter taste of the starting material was not present in the product.

EXAMPLE 5

[0117] 1.9 kg of Moringa seeds obtained from plants grown in Israel, milled after oil extraction, were used as a starting material. The seeds were determined to contain ˜50% protein, ˜25% fiber, and ˜10% fat. The Moringa seeds were mixed with 7.7 kg of hot (˜93° C.) tap water to form a mixture having a pH of ˜5.4. The mixture was stirred for 45 minutes while the temperature was maintained at 93-98° C. The mixture was then filtered on a 20 μm filter cloth. And additional 7.7 kg of hot (92° C.) tap water was added to the wet solids remaining after filtration to form a slurry and stirred for an additional 5-10 minutes. The slurry was filtered, yielding ˜3.6 kg of wet cake, which was dried in a vacuum oven at 70° C. and a pressure of 20-50 mbar. After drying, ˜1 kg of a dry powder was obtained.

[0118] The powder contained ˜47% by weight protein, and had an improved taste relative to the starting material.

EXAMPLE 6

[0119] A number of tests were made in which raw Moringa seeds were washed with organic solvents and then dried as described above. Results of the tests are summarized in Tables 1 and 2.

TABLE-US-00001 TABLE 1 Material Total protein, % Taste Raw moringa seed 45.5 4 Moringa seed after ethanol wash 54.4 5

TABLE-US-00002 TABLE 2 Material Total protein, % Taste Raw moringa seed 52.2 4 Moringa seed after 1:5 ethylacetate wash 46.1 5 and filtration Moringa seed after 1:5 methanol wash, not determined 3 followed by 1:5 ethanol wash and filtration

[0120] As can be seen from the results summarized in the tables, in no case did washing with organic solvent significantly improve the taste of the Moringa seed.

EXAMPLE 7

[0121] A series of experiments were performed in which the Moringa seed starting material was contacted a single time with an excess of room temperature tap water. The Moringa raw material comprised 45.5% protein and 12.3% fat, and was characterized by a loss on drying (LOD) of 7.4% and a protein content (dry basis) of 49.1%. The starting material was characterized by a bitterness of 4 on the scale described above.

[0122] In one experiment, 50 g of starting material were mixed with a fourfold excess of water, and the water then extracted without an additional step of washing. The final product had a bitterness level of 4 on the scale described above.

[0123] In a second experiment, 3 g of starting material were mixed with a tenfold excess of water, and the water then extracted without an additional step of washing. The final product had a bitterness level of 4 on the scale described above.

[0124] These experiments indicate that a single contact with water is insufficient, and the Moringa seed material needs to be contacted at least twice with water.

EXAMPLE 8

[0125] A series of experiments were performed in which the same starting material used in the previous example was washed with different amounts of water at different temperatures and then dried as described above. The results are summarized in Table 3.

TABLE-US-00003 TABLE 3 Moringa Moringa/ starting water ratio Dry Total Protein, material first second contact product, protein, LOD, % w/w (g) contact contact T, ° C. g % w/w % w/w dry basis Taste 50 1:17 1:9 40 21.9 —.sup.a —.sup.a —.sup.a 1 50 1:16 1:8 45 23.9 30.0 1.8 30.6 2 50 1:17 1:9 26 20.6 37.1 2.0 37.9 1 .sup.anot measured

[0126] The results of the experiments summarized in the table show that raising the temperature of the water used to contact the Moringa material from room temperature to 45° C. does not significantly affect the taste or the protein content of the final product, and retains some two thirds of the protein content of the starting material.

EXAMPLE 9

[0127] A series of experiments were performed in which the procedure was performed as above, using the same starting material as in the preceding two examples, except that the second contact with water was performed using a 1:1 Moringa/water ratio. The results are summarized in Table 4.

TABLE-US-00004 TABLE 4 Moringa starting Moringa/ Dry Total Protein, material water ratio contact product, protein, LOD, % w/w (g) (first contact) T, ° C. g % w/w % w/w dry basis Taste 50 1:5 25-26 23.2 32.9 0.9 33.2 3 50 1:5 26 24.1 30.0 1.8 33.3 3 50 1:4 23-24 25.1 30.5 3.1 31.5 2

[0128] These results show that lowering the Moringa:water ratio in the second contact does not significantly improve the protein content of the final product, but that the product formed under these conditions has a significantly more bitter taste than that made when the second contact is performed using an excess of water.

EXAMPLE 10

[0129] A series of experiments was performed in which the contact with water was performed at high temperature. In these experiments, the water was heated prior to contact with the Moringa seed material, and the contact was performed with heating. Some of the runs were performed on a laboratory scale (˜50 g of starting material), while others were performed at a pilot industrial scale (˜1 kg of starting material). The results are summarized in Table 5.

TABLE-US-00005 TABLE 5 Moringa Moringa/ starting water ratio Dry Total Protein, material first second contact product, protein, LOD, % w/w (g) contact contact T, ° C. g % w/w % w/w dry basis Taste  45.sup.a 1:4 1:4 92-98 23.4 45.0 4.3 47.0   0.5 1002.sup.b 1:4 1:4   88-92.5 611.5 26.5 3.1 27.3 1-1.5 1002.sup.c 1:4 1:4   82-91.5 605.6 23.1 3.2 23.9 1-1.5 1000.sup.d 1:4 1:4 89-95 418 39.9 4.9 41.9 1 1006.sup.d 1:4 1:4 91-93 478 40.0 7.1 43.1 1 1000.sup.d 1:4 1:4 90-91 540 40.2 5.4 42.5 1  750.sup.d 1:4 1:4 91-93 299 41.7 5.8 44.3 1 1000.sup.e 1:4 1:4 90-93 516 54.2 4.2 56.5 1-1.5 1000.sup.e 1:4 1:4 90-93 544 52.9 3.4 54.7 1-1.5 1000.sup.e 1:4 1:4 89 520 52.4 2.5 53.7 1-1.5 1000.sup.e 1:4 1:4 91-92 288 53.0 1.7 53.9 1-1.5 .sup.aStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 50.1% total protein, 10.2% fat, LOD 7.3%, 54.1% total protein (dry basis); bitterness 3.5-4 .sup.bStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 32.4% total protein, LOD 4.7%, 34.0% total protein (dry basis); bitterness 3.5-4 .sup.cStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 30.5% total protein, LOD 4.6%, 32.0% total protein (dry basis); bitterness 3.5-4 .sup.dStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 44.9% total protein, LOD 7.3%, 48.4% total protein (dry basis); bitterness 3.5-4 .sup.eStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 47.2% total protein, LOD 4.6%, 49.5% protein (dry basis), 15.6% fat (3.9% saturated), 5.3% ash, 18.0% deitary fiber, 9.3% carbohydrates (3.3% total sugar); bitterness 3.5-4

[0130] The results show that that performing the contact with water under heating does not adversely affect the flavor or protein content of the final product. In addition, the results demonstrate that scaling up the process does not affect its efficiency or the quality of the final product.

EXAMPLE 11

[0131] Experiments were performed in which both stages of contact with water were performed under acid conditions. In each case, prior to the contact with the Moringa seed material, the pH of the water was adjusted to 4.5 by addition of HCl or citric acid. The results of the experiments are summarized in Table 6.

TABLE-US-00006 TABLE 6 Moringa Moringa/ starting water ratio Dry Total Protein, material first second contact product, protein, LOD, % w/w (g) contact contact T, ° C. g % w/w % w/w dry basis Taste 50.sup.a 1:4 1:1 23-24 20.7 26.5 3.1 27.3 1.5 50.sup.a .sup. 1:4.4 .sup. 1:0.6 23-24 21.8 28.1 2.7 28.8 1.5-2   50.sup.a  1:16  1:8.sup.e 25-28 22.9 44.8 2.3 45.8 0-1 50.sup.b 1:4 1:1 20.7 19.3 34.1 3.4 35.3 2.5 50.sup.b 1:4 1:4 19.5 19.8 30.8 9.5 34.1 1 50.sup.b 1:4 1:4 22 16.7 34.2 3.1 35.3 1.5 50.sup.b 1:4 1:4 22.2 16.9 32.9 2.7 33.9 1.5 45.sup.b 1:4 1:4 3 20.1 39.9 4.4 41.7 2 45.sup.b 1:4 1:4 4 18.6 39.6 7.0 42.6 1.5 50.sup.c 1:4 1:4  4-14 19.3 32.1 1.6 32.6 1.5 50.sup.c 1:4 1:4 17-18 18.7 29.9 1.9 30.5 2 45.sup.d 1:4 1:4 89-97 17.3 34.6 6.9 37.2 2 45.sup.d 1:4 1:4 89-97 18.4 38.3 4.0 39.9   1-1.5 .sup.aStarting material: Milled defatted seed cake from moringa seeds from plants grown in Israel; 45.5% total protein, 12.3% fat, LOD 7.4%, 49.1% total protein (dry basis); bitterness 4 .sup.bStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 52.2% total protein, 7.5% fat, LOD 6.2%, 55.7% total protein (dry basis); bitterness 4 .sup.cStarting material: Milled defatted seed cake from moringa seeds from plants grown in Israel; 38.8% total protein, 3.6% fat, LOD 8.8%, 42.6% total protein (dry basis); bitterness 5 .sup.dStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 50.1% total protein, 10.2% fat, LOD 7.3%, 54.1% total protein (dry basis); bitterness 3.5-4 .sup.eSecond contact with water was followed by a third contact using water adjusted to a pH of 9-9.5 and a moringa/water ratio of 1:0.85

[0132] The results of these experiments indicate that performing the steps of contacting the Moringa seed material with water under acid conditions does not yield results that are significantly from those obtained when plain water (i.e. at neutral pH) is used. Both the bitterness of, and the amount of protein in, the product are similar to those of the product obtained from use of water without any adjustment of the pH.

[0133] The results of these experiments also show that the temperature of the water used to treat the Moringa seed material does not significantly affect the protein content or taste of the product.

EXAMPLE 12

[0134] Starting material comprising 50 g of milled defatted seed cake from Moringa seeds from plants grown in India and characterized as containing 50.1% total protein, LOD 7.3%, 54.1% total protein (dry basis) was treated according to the method disclosed herein. The second contact with water was performed under basic conditions, the pH of the water used for the second contact having been adjusted to 9-9.5 prior to the contact. The second contact was performed at a temperature of 31-35° C. A 3.6 g sample of dry product was obtained from the filtrate obtained after filtration of the product of the second washing. The product was characterized as having a 24.2% total protein content, LOD 13.2% and 27.9% protein (dry basis). The product had a salty taste.

EXAMPLE 13

[0135] In order to compare the method disclosed herein with similar methods known in the prior art, Moringa seed material was treated according to the method for extracting protein from plant material as disclosed in '041. In this method, the starting material was first contacted with aqueous base at a pH of 9, and then with aqueous acid at a pH of 4. The results are summarized in Table 7.

TABLE-US-00007 TABLE 7 Moringa Moringa/ starting water ratio Dry Total Protein, material first second contact product, protein, LOD, % w/w (g) contact contact T, ° C. g % w/w % w/w dry basis Taste 50.sup.a 1:4 1:4 4-15 18.2 32.4 1.7 33.0 0.5-1 4000.sup.a  1:4 1:4 7-10 1104 32.7 4.4 34.2 1.5 50.sup.b 1:4 1:4 8-18 20.7 35.4 9.2 38.9 0.5 4000.sup.b, c  1:4 1:4 7-11 1784 35.2 3.1 36.3 0.5-1 .sup.aStarting material: Milled defatted seed cake from moringa seeds from plants grown in Israel; 38.8% total protein, 3.6% fat, LOD 8.8%, 42.6% total protein (dry basis); bitterness 5 .sup.bStarting material: Milled defatted seed cake from moringa seeds from plants grown in India; 50.1% total protein, 10.2% fat, LOD 7.3%, 54.1% total protein (dry basis); bitterness 3.5-4 .sup.cDetailed analysis determined product to contain 8.0% fat, 1.5% sugars (=total carbohydrates), 49.2% dietary fiber (36.1% soluble fiber, 13.1% insoluble), and 3.0% ash

[0136] While the method of '041 did succeed in removing the bitter taste of the starting material, and yielded a final product similar in its protein content to that of the product of the method disclosed herein, it did not produce results that were significantly better than those of the method disclosed herein. That is, these results clearly demonstrate that no step of pH adjustment is necessary in a treatment of Moringa seeds that will improve their palatability while retaining the majority of their food values.

EXAMPLE 14

[0137] In order to compare the protein content of the Moringa seed product produced by the process disclosed herein with that of raw Moringa seeds, SDS-PAGE electrophoresis with Coomassie staining was performed on samples of raw Moringa seeds and a sample of the product of the method disclosed herein; the sample comprised 47.2% (w/w) total protein. Reference is now made to FIG. 3, which presents the results of the electrophoresis (10 μg protein per lane). The results for electrophoresis of the product of the process disclosed herein are shown in lane 2 (notated as “257” in the figure), while those for the raw Moringa seeds are shown in lane 3 (notated as “258” in the figure). The results are summarized in Table 8.

TABLE-US-00008 TABLE 8 Raw moringa seeds Treatment product Band # MW (kDa).sup.a Band % MW (kDa).sup.a Band % 1 43.0 ± 1.3  2.90 43.7 ± 1.3 2.21 2 32.5 ± 1.0 14.95 32.9 ± 1.0 7.77 3 — — 30.4 ± 0.9 8.14 4 19.4 ± 0.6 12.94 19.7 ± 0.6 12.42 5  6 ± 1 69.21  6 ± 1 69.46 .sup.areported errors are estimated 1σ uncertainties

[0138] As can be seen from the electrophoresis results, the protein composition of the Moringa seed product is quite similar to that of the raw Moringa seed starting material. All of the bands present in the electrophoresis of the raw Moringa seed starting material are present in the electrophoresis of the product of the method of treatment disclosed herein, with molecular weights that are identical to within experimental error. One new band appears at 30.4±0.9 kDa; from the relative band intensities, it appears bands 2 and 3 in the electrophoresis of the treatment product represent the same protein as band 2 in electrophoresis of the raw Moringa seed. Without wishing to be bound by theory, it appears that the production process may have induced partial denaturation of a portion of the protein making up band 2 that led to a change (e.g. a conformational change) that altered its R.sub.f value.

[0139] An amino acid profile of the protein content of the Moringa treatment product of Table 8 is given in Table 9.

TABLE-US-00009 TABLE 9 percent of total amino Amino acid add content alanine 4.95 arginine 13.46 aspartic acid 5.80 cysteine + cystine 3.90 glutamic acid 20.37 glycine 5.63 histidine 2.75 isoleucine 3.98 leucine 7.11 lysine 1.81 methionine 2.11 phenylalanine 5.50 proline 6.58 serine 3.68 threonine 3.23 tryptophan 1.53 tyrosine 2.60 valine 5.00

[0140] While the sample overall was enriched in protein relative to the starting material, the overall distribution of amino acids was quite similar to values reported in the literature.