Abstract

Introduction. Whipped dairy products can be used both as finished and semi-finished products in confectionery industry. Therefore, this sphere constantly requires new technologies. A wide range of additives, stabilizers, and structure-forming agents make it possible to get products with programmed sensory, structural, and mechanical properties. Enzymatic processing of milk base is one of the modern directions in the development of whipping process, as it requires no artificial components. Enzyme preparations of plant and microbial origin were developed to satisfy the needs of the increasing production demand and to compensate for the acute shortage of animal rennet. These enzymes have a high proteolytic activity and exhibit good technological properties in dairy industry. The research objective was to study the fermentation process with preparations of different origin and optimize the proteolysis process to obtain a milk base with a high foaming capacity and maximal stability.
Study objects and methods. The research featured samples of fermented reduced skim milk. The following enzymes were selected for enzymatic hydrolysis: animal origin – rennet-beef enzyme SG-50 (Russia), chicken-beef enzyme KG-50 (Russia), pepsin (Russia); microbial nature – Fromase 750 (France), Pronase E (Russia); recombinant chymosin-preparation CHY-MAX M (Denmark). The fermented systems were tested for foaming ability, foam stability, relative content of free amino acids, and the diameter of casein micelles during hydrolysis by the ratio of the height of the foam column to the initial volume. The relative content of free amino acids was determined using the method of formal titration. The diameter of casein micelles during hydrolysis was determined by dynamic light scattering using a particle size analyzer in low-volume plastic cuvettes. These indicators were determined after inactivation of enzymes by pasteurization at 90–92°C for 3–5 sec.
Results and discussion. Enzyme preparations of various natures were added to milk. The temperature and duration were measured as rational parameters of fermentation. After inactivation of the enzymes by pasteurization method, the foaming capacity, foam stability, and the relative content of free amino acids were determined every 30 minutes after application of the preparation. The greatest foaming properties (800%) were observed in the milk base fermented with the recombinant enzyme CHY-MAX M. However, the use of this preparation in commercial production was found undesirable due to the high activity of the enzyme and the resulting complexity of the control process. The lowest foaming ability was observed in the milk sample fermented with preparations of animal origin – SG-50, KG-50, and pepsin. The optimal foaming capacity and stable whipped mass were registered in the samples hydrolyzed with microbial preparations Fromase and Pronase. Under certain rational parameters, the foaming capacity of milk was 740% and 700%, respectively, while the stability was 80%.
Conclusion. The research featured a comparative analysis of the foaming capacity and stability of reduced skim milk foam obtained using preparations of animal and microbial origin. The enzymes of the microbial group showed the best results for the enzymatic hydrolysis of proteins in reduced milk.

Keywords

Enzymatic hydrolysis, reduced milk, foaming capacity, microbial enzymes, animal enzymes, foam stability

REFERENCES

1. Prosekov AYu, Podlegaeva TV, Novikov RS. Fermentatsiya moloka dlya povysheniya penoobrazuyushchey sposobnosti [Milk fermentation as a means of increasing the foaming capacity]. Dairy Industry. 2002;(6):47. (In Russ.).
2. Prosekov AYu, Podlegaeva TV, Sergeeva IS. Biologicheskaya obrabotka moloka dlya uluchsheniya svoystv pri poluchenii dispersnykh molochnykh produktov [Biological processing of milk as a means of improving the properties of dispersed dairy products]. Storage and Processing of Farm Products. 2002;(8):45–47. (In Russ.).
3. Prosekov A, Babich O, Kriger O, Ivanova S, Pavsky V, Sukhikh S, et al. Functional properties of the enzyme-modified protein from oat bran. Food Bioscience. 2018;24:46–49. DOI: https://doi.org/10.1016/j.fbio.2018.05.003.
4. Jacob M, Jaros D, Rohm H. Recent advances in milk clotting enzymes. International journal of dairy technology. 2011;64(1):14–33. DOI: https://doi.org/10.1111/j.1471-0307.2010.00633.x.
5. Lebedeva GV, Proskuryakov MT. Purification and characterization of milk-clotting enzymes from oyster mushroom (Pleurotus ostreatus (Fr.) Kumm). Applied Biochemistry and Microbiology. 2009;45(6):623–625. DOI: https://doi.org/10.1134/S0003683809060088.
6. Leite Junior BRDC, Tribst AAL, Grant NJ, Yada RY, Cristianini M. Biophysical evaluation of milk-clotting enzymes processed by high pressure. Food Research International. 2017;97:116–122. DOI: https://doi.org/10.1016/j.foodres.2017.03.042.
7. Alecrim MM, Palheta RA, Teixeira MFS, Oliveira IMA. Milk-clotting enzymes produced by Aspergillus flavo furcatis strains on Amazonic fruit waste. International Journal of Food Science and Technology. 2015;50(1):151–157. DOI: https://doi.org/10.1111/ijfs.12677.
8. Zimina MI, Sukhih SA, Babich OO, Noskova SYu, Abrashina AA, Prosekov AYu. Investigating antibiotic activity of the genus bacillus strains and properties of their bacteriocins in order to develop next-generation pharmaceuticals. Foods and Raw Materials. 2016;4(2):92–100. DOI: https://doi.org/10.21179/2308-4057-2016-2-92-100.
9. Jensen JL, Jacobsen J, Moss ML, Rasmussen F, Qvist KB, Larsen S, et al. The function of the milk-clotting enzymes bovine and camel chymosin studied by a fluorescence resonance energy transfer assay. Journal of Dairy Science. 2015;98(5):2853–2860. DOI: https://doi.org/10.3168/jds.2014-8672.
10. Yegin S, Fernandez-Lahore M, Jose Gama Salgado A, Guvenc U, Goksungur Y, Tari C. Aspartic proteinases from Mucor spp. in cheese manufacturing. Applied Microbiology and Biotechnology. 2011;89(4):949–960. DOI: https://doi.org/10.1007/s00253-010-3020-6.
11. Prosekov AYu, Podlegaeva TV, Novikov RS. Penoobrazuyushchaya sposobnostʹ vosstanovlennogo tselʹnogo moloka [Foaming ability of reduced whole milk]. News of institutes of higher education. Food technology. 2001;264–265(5–6):39–40. (In Russ.).
12. Prosekov A, Babich O, Kriger O, Ivanova S, Pavsky V, Sukhikh S, et al. Functional properties of the enzyme-modified protein from oat bran. Food Bioscience. 2018;24:46–49. DOI: https://doi.org/10.1016/j.fbio.2018.05.003.
13. Kumar ABV, Gowda LR, Tharanathan RN. Non-specific depolymerization of chitosan by pronase and characterization of the resultant products. European Journal of Biochemistry. 2004;271(4):713–723. DOI: https://doi.org/10.1111/j.1432-1033.2003.03975.x.
14. Shlyapnikova SV, Batyrova ER. Features of coagulation of milk. Rennet enzyme preparation and its analogues. Biomics. 2017;9(1):033–041. (In Russ.).
15. Abesinghe AMNL, Islam N, Vidanarachchi JK, Prakash S, Silva KFST, Karim MA. Effects of ultrasound on the fermentation profile of fermented milk products incorporated with lactic acid bacteria. International Dairy Journal. 2019;90:1–14. DOI: https://doi.org/10.1016/j.idairyj.2018.10.006.
16. Kharitonov VD, Geraimovich OA. Technology of continuous fermentation process in the production of fermented milk products. Innovatsii v selʹskom khozyaystve [Innovations in Agriculture]. 2019;33(4):154–161.
17. Gavrilova E, Anisimova E, Gabdelkhadieva A, Nikitina E, Vafina A, Yarullina D, et al. Newly isolated lactic acid bacteria from silage targeting biofilms of foodborne pathogens during milk fermentation. BMC Microbiology. 2019;19(1). DOI: https://doi.org/10.1186/s12866-019-1618-0.
18. Halavach TN, Zhabanos NK, Furyk NN, Kurchenko VP, Rizevsky SV. The fetures of complex fermentation of milk proteins with different lactic acid bacteria. Food Industry: Science and Technology. 2013;19(1):76–84. (In Russ.).
19. Beermann C, Hartung J. Physiological properties of milk ingredients released by fermentation. Food and Function. 2013;4(2):185–199. DOI: https://doi.org/10.1039/c2fo30153a.
20. Zhao X, Wang J, Zheng Z, Zhao A, Yang Z. Production of a milk-clotting enzyme by glutinous rice fermentation and partial characterization of the enzyme. Journal of Food Biochemistry. 2015;39(1):70–79. DOI: https://doi.org/10.1111/jfbc.12108.
21. Khanal SN, Lucey JA. Evaluation of the yield, molar mass of exopolysaccharides, and rheological properties of gels formed during fermentation of milk by Streptococcus thermophilus strains ST-143 and ST-10255Y. Journal of Dairy Science. 2017;100(9):6906–6917. DOI: https://doi.org/10.3168/jds.2017-12835.
22. Hernndez-Ledesma B, Amigo L, Ramos M, Recio I. Application of high-performance liquid chromatography-tandem mass spectrometry to the identification of biologically active peptides produced by milk fermentation and simulated gastrointestinal digestion. Journal of Chromatography A. 2004;1049(1–2):107–114. DOI: https://doi.org/10.1016/j.chroma.2004.07.025.