USE OF A THERMOPLASTIC, BIOBASED AND BIODEGRADABLE MATERIAL HAVING BRITTLE FRACTURE MECHANICS AS A SHELL FOR AN EGG OR EGG-REPLACEMENT PRODUCT, AND VEGAN EGG-REPLACEMENT PRODUCT ENCASED BY SUCH A SHELL

Abstract

The invention relates to a use of an extruded material, including (A) one or more biodegradable, thermoplastically processable biopolymer(s) and (B) one or more inorganic, organic or low-solubility salt(s) as a shell for an egg-replacement product, and to an egg-replacement product including vegan-based egg white and egg yolk which are encased by the shell.

Claims

1. A use of a material made from (A) one or more biodegradable, thermoplastically processable biopolymer(s), and (B) one or more inorganic, organic or hardly soluble salt(s) as a shell for an egg replacement product.

2) The use according to claim 1, wherein the material is produced from components (A) and (B) by extrusion.

3) The use according to claim 1 or 2, wherein the biopolymer (A) is characterized by a degradation rate of at least 90% within 180 days, an achieved disintegration level of less than 10% dry mass with particles larger than 2 mm after 12 weeks and/or passed ecotoxicity analysis regarding plant growth.

4) The use according to one of claims 1-3, wherein the biopolymer (A) is a polyhydroxyalkanoate, polyhydroxyalkanoate copolymer or polylactide.

5) The use according to one of claims 1-4, wherein the salt (B) is a carbonate, sulfate, hydrogen sulfate, sulfite, sulfide, phosphate, hydrogen phosphate, oxide, hydroxide, citrate or oxalate of an alkaline earth element, a transition metal or aluminum.

6. The use according to one of claims 1-5, wherein the salt (B) is CaCO.sub.3, CaSO.sub.4, Ca.sub.3(PO.sub.4).sub.2, MgCO.sub.3, BaSO.sub.4, Ca-citrate, Ca-oxalate, Fe.sub.2O.sub.3 or Al.sub.2O.sub.3.

7. The use according to one of the claims 4-6, wherein the polyhydroxyalkanoate and/or the polyhydroxyalkanoate copolymer is a poly(3-hydroxypropionate), poly(3-hydroxybutyrate), poly(3-hydroxyvalerate), poly(3-hydroxyhexanoate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), poly(3-hydroxynonanoate), poly(3-hydroxydecanoate), poly(3-hydroxyundecanoate), poly(3-hydroxydodecanoate), poly(3-hydroxytetradecanoate), poly(3-hydroxypentadecanoate), poly(3-hydroxyhexadecanoate); poly(3-hydroxypropionate-co-3-hydroxybutyrate), poly(3-hydroxypropionate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), medium chain PHAs with side chain lengths of C.sub.3-C.sub.11 or long chain PHAs with side chain lengths greater than C.sub.12.

8. The use according to one of the claims 4-6, wherein the polylactide is an amorphous or crystalline variant of poly (L-lactide) PLLA, poly (D-lactide) PDLA, stereocomplex (polylactide) sc-PLA, stereoblock (polylactide) sb-PLA.

9. An egg substitute product, comprising: an egg white and egg yolk on a vegan basis, enveloped by a shell made from a material produced by extrusion from (A) one or more biodegradable, thermoplastically processable biopolymer (s), and (B) one or more inorganic, organic or hardly soluble salt(s), wherein both albumen and yolk include (a) vegetable protein from legumes, oilseeds, cereals and/or algae, and (b) a combination of at least two hydrocolloids with a different reaction to temperature changes.

Description

[0085] The invention is described in more detail with reference to drawing figures, wherein:

[0086] FIG. 1 illustrates a microscopic structure of a chicken egg shell (taken from reference [1]);

[0087] FIG. 2: illustrates water vapor and oxygen permeability of various polymers (adapted from reference [23]);

[0088] FIG. 3: illustrates tensile strength and stiffness (modulus of elasticity) of various polymers (adapted from reference [23]);

[0089] FIG. 4: Exemplary representations of the finished eggshell.

[0090] The following examples are as possible embodiments and do not represent any restriction to exactly these embodiments.

EMBODIMENTS

Embodiment 1; Production of Compound from PHBV and CACO.SUB.3

[0091] PHBV with a melting point of 175 C. was dried overnight at 50 C. and CACO.sub.3 at 100 C., mixed in powder form in a ratio of 7:3 and compounded and granulated at a temperature profile of 45-140-150-150-150 C. A pressed film with a thickness of approx. 240 m was produced from the light brown granules. The gas permeability measurement showed a water vapor permeability (WVTR, 85->0% relative humidity, 23 C.) of 1.8 g m.sup.2 d.sup.1 (normalized to 100 m: 4.4 g m.sup.2 d.sup.1) and an oxygen permeability (OTR, 23 C./50% relative humidity) of 10.5 cm.sup.3 m.sup.2 d.sup.1 (normalized to 100 m: 67.2 cm.sup.3 m.sup.2 d.sup.1). The mechanical tensile test showed a tensile strength of 21.6 MPa, an elongation at break of 1.1% and a modulus of elasticity of 2.9 GPa.

Embodiment 2: Production of Compound from PLLA and CaCO.SUB.3

[0092] PLLA with low proportion of D-isomers (melting point 160 C.) was dried at 60 C. and CaCO.sub.3 at 100 C. overnight, mixed in powder form in a ratio of 8:2 and at a temperature profile of 60-160-190-190-145-145-145 C. compounded and granulated. A pressed film with a thickness of approx. 200 m was produced from the whitish granules. The gas permeability measurement showed a water vapor permeability (WVTR, 85->0% relative humidity, 23 C.) of 11 gm.sup.2 d.sup.1 (normalized to 100 m: 22 g m.sup.2 d.sup.1) and an oxygen permeability (OTR, 23 C./50% relative humidity) of 75 cm.sup.3 m.sup.2 d.sup.1 (normalized to 100 m: 150 cm.sup.3 m.sup.2 d.sup.1). The mechanical tensile test showed a tensile strength of 40 MPa, an elongation at break of 1.0% and a modulus of elasticity of 4 GPa.

[0093] FIGS. 2 and 3 show a comparison of the achieved permeation and mechanical properties of the compounds of embodiments 1 and 2 to standard polymers for food packaging.

Embodiment 3: Structure and Shape of the Shell

[0094] The compound from embodiment 1 is formed into two rotationally symmetrical half-shells of the same height through an injection molding process (see FIG. 4). Before thermoplastic processing, the compound is dried at 50-80 C. for 6-48 hours. Depending on the stability and viscosity of the melt, the temperature profile in the injection molding extruder corresponds to that of the previous compounding process, but can also be selected slightly higher if necessary. In order to ensure suitable material and heat distribution in the injection mold, the geometry of the injection point can be configured either centrally or equatorially. The volume of the egg-shaped hollow body, which results from the combination of the two half-shells, corresponds to that of a larger hen's egg and is between 60-65 ml. The shell thickness of the injected half-shells corresponds approximately to that of a hen's egg, i.e. approx. 0.6-0.75 mm. The two half-shells have a plug-in mechanism along the equator, which makes it possible to join them with a perfect fit. In the area of the plug-in connection, the shell thickness increases slightly, by a factor of about 2, in order to ensure greater mechanical stability here. One of the two half-shells, ideally the one at the top, which narrows towards the tip, has an opening of between 3 and 5 mm on the side in the upper third or centrally on the axis of rotation, which is formed during the injection molding process. This opening makes it possible to fill the resulting hollow body, which results from the firm connection of the two egg shell halves, with one or more flowable and conveyable components (egg white and optionally egg yolk).

BIBLIOGRAPHY

[0095] 1. Arias, J. L., et al., Eggshell Growth and Matrix Macromolecules. Handbook of Biomineralization, 2008. [0096] 2. Hahn, E. N., et al., Nature's technical ceramic: the avian eggshell. Journal of the Royal Society Interface, 2017. 14(126). [0097] 3. Lomholt, J. P., The Development of the Oxygen Permeability of the Avian Egg Shell and Its Membranes during Incubation. Journal of Experimental Zoology, 1976. 198(2): p. 177-184. [0098] 4. Spiesz, E. M., et al., Bacterially Produced, Nature-inspired Composite Materials. Small, 2019. 15(22): p. 1805312. [0099] 5. Jost, V., Effect of additives on the mechanical and permeation properties of biopolymer films from alginate and PHBV PhD, 2019. TU Munich: Freising [0100] 6. Hochrein, T. and I. Alig, Prozessmesstechnik in der Kunststoffaufbereitung 2011, Wrzburg: Vogel Buchverlag. [0101] 7. Cinelli, P., et al., Biocomposites Based on Polyhydroxyalkanoates and Natural Fibers from Renewable Byproducts. Applied Food Biotechnology, 2019. 6(1): p. 35-43. [0102] 8. Chen, G. X., et al., Crystallization kinetics of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/clay nanocomposites. Journal of Applied Polymer Science, 2004. 93(2): p. 655-661. [0103] 9. Duangphet, S., et al., Effect of Calcium Carbonate on Crystallization Behavior and Morphology of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate). Key Engineering Materials, 2017. 751: p. 242-251. [0104] 10. Cabedo, L, et al., Studying the degradation of polyhydroxybutyrate-co-valerate during processing with clay-based nanofillers. Journal of Applied Polymer Science, 2009. 112(6): p. 3669-3676. [0105] 11. Ding, Y., et al., Mechanical properties, thermal stability, and crystallization kinetics of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium carbonate composites. Polymer Composites, 2011. 32(7): p. 1134-1142. [0106] 12. Kirboga, S. and M. ner, The properties of PHBV/CaCO3 composites prepared by melt processing, in 6th International Conference on New Trends in Chemistry. 2020. virtual. [0107] 13. Xiong, L, et al., Preparation of PBS and CaCO.sub.3 Composite Degradable Materials based on Melt Blending. IOP Conference Series: Materials Science and Engineering, 2020. 730: p. 012012. [0108] 14. Gigante, V., et al., Evaluation of Mussel Shells Powder as Reinforcement for PLA-Based Biocomposites. International Journal of Molecular Sciences, 2020. 21(15). [0109] 15. Sathiyavimal, S., et al., Natural organic and inorganic-hydroxyapatite biopolymer composite for biomedical applications. Progress in Organic Coatings, 2020. 147: p. 105858. [0110] 16. Misra, S. K., et al., Polyhydroxyalkanoates (PHA)/Inorganic Phase Composites for Tissue Engineering Applications. Biomacromolecules, 2006. 7(8): p. 2249-2258. [0111] 17. Rodriguez-Contreras, A., Recent Advances in the Use of Polyhydroyalkanoates in Biomedicine. Bioengineering, 2019. 6(3). [0112] 18. Chemozem, R. V., et al., Piezoelectric 3-D Fibrous Poly(3-hydroxybutyrate)-Based Scaffolds Ultrasound-Mineralized with Calcium Carbonate for Bone Tissue Engineering: Inorganic Phase Formation, Osteoblast Cell Adhesion, and Proliferation. ACS Applied Materials & Interfaces, 2019. 11(21): p. 19522-19533. [0113] 19. Jagoda. A., Polyhydroxyalkanoate-based thin films: characterization and optimization for calcium phosphate crystallization PhD, 2013. University of Basel: Basel [0114] 20. Degli Esposti, M., et al., Highly porous PHB-based bioactive scaffolds for bone tissue engineering by in situ synthesis of hydroxyapatite. Materials Science and Engineering: C, 2019. 100: p. 286-296. [0115] 21. Kulman, D. Imitation egg product 2019. US20190263557A1. [0116] 22. Fink, D., et al., Flexible, atmungsaktive Polymerfolie und Verfahren zu deren Herstellung 2003. DE10301984A1. [0117] 23. Detzel, A., et al., Biobasierte Kunststoffe al Verpackung von Lebensmitteln, Heidelberg, Freising, Berlin, 2018.