Functional properties and possibility of application of whey protein hydrolysates obtained by biotechnological processing

Abstract

The amount of whey products on the market is negligible in relation to the amount of unused whey, which leads to the conclusion that developing and improving the process of whey processing must introduce new unconventional products, which would take a more significant place in the range of consumer products. In this sense, the aim of this doctoral dissertation was the production and characterization of bioactive whey proteins hydrolysates, which as such could be applied separately or in combination with other food products. In order to produce bioactive whey protein hydrolysates, a selection of an optimal biotechnological process for the production of hydrolysates with improved biological properties was performed. In the research, selection of optimal microorganisms and enzymes, optimization of the processes of fermentation and enzymatic hydrolysis were performed in order to produce hydrolysates of high biological activity. The produced hydrolysates are analyzed in both the bioactivity aspect and the aspect of their functional characteristics, after which the optimal production process was adopted. In the last phase of the research, a proposal for the application of the produced bioactive hydrolysate in a confectionery fat filling was made. The fat filling enriched with bioactive hydrolysate of whey proteins has been thoroughly examined in terms of sensory characteristics and texture, and the formulation by which it is possible to obtain a final product with optimal characteristics is proposed. During the selection of microorganisms and enzymes, biotechnological modification of whey proteins was carried out using Lactobacillus acidophilus ATCC 4356, Lactobacillus rhamnosus ATCC 7469 and Lactobacillus reuteri ATCC 23272 strains, as well as commercial enzymes Pepsin® and Tripsin®. Fermentation and enzymatic hydrolysis processes are optimized with the aim of producing hydrolysates with high antioxidant activity. After that, the selection of optimal bacterial strain and enzyme was performed, as well as the optimal processes conditions. During the selection, the antioxidant activity, the protein and amino acid content, the degree of hydrolysis, the foam formation ability, emulsifying properties, digestibility and bioavailability were monitored. The obtained bioactive hydrolysates were then dried, analysed and added, in powder form, to the fat filling as a model of the confectionery product. During the characterization, antioxidant, antirheumatic, anti-inflammatory and antimicrobial activity, the ability to inhibit lipid peroxidation, and the stability of the antioxidant activity of the produced hydrolysate powder were monitored. After that, an optimal amount of hydrolysate powders, which can be added to the fat filling without adversely affecting its sensory properties and texture, was tested...

Količina proizvoda od surutke na tržištu je zanemarljivo mala u odnosu na količinu surutke koja se nepropisno odlaže što navodi na zaključak da bi se razvojem i unapređenjem procesa prerade surutke mogli dobiti novi nekonvencionalni proizvodi koji bi zauzeli značajnije mesto u paleti proizvoda namenjenih širokoj potrošnji. U tom smislu cilj ove doktorske disertacije je bio proizvodnja i karakterisanje bioaktivnih hidrolizata proteina surutke, koji bi kao takvi mogli biti primenjeni zasebno ili u kombinaciji sa drugim prehrambenim proizvodima. U cilju proizvodnje bioaktivnih hidrolizata proteina surutke izvršena je selekcija optimalnog biotehnološkog procesa pomoću koga se mogu proizvesti hidrolizati proteina surutke unapređenih bioloških svojstava. U okviru istraživanja izvršena je selekcija optimalnih kultura mikroorganizama i enzima, optimizacija uslova procesa fermentacije i enzimske hidrolize u cilju proizvodnje hidrolizata visoke biološke aktivnosti. Proizvedeni hidrolizati su detaljno okarakterisani kako sa stanovišta bioaktivnosti tako i sa stanovišta njihovih funkcionalnih karakteristika, nakon čega je usvojen optimalan proces proizvodnje.. U poslednjoj fazi istraživanja dat je predlog primene proizvedenog bioaktivnog hidrolizata u masnom kremu namenjenom konditorskoj industriji. Konditorski masni krem obogaćen bioaktivnim hidrolizatom proteina surutke je detaljno ispitan po pitanju senzornih karakteristika i teksture na osnovu čega je predložena receptura čijom primenom je moguće dobiti fimalni proizvod optimalnih karakteristika. Tokom selekcije kultura mikroorganizama i enzima izvršena je biotehnološka modifikacija proteina surutke primenom sojeva Lactobacillus acidophilus ATCC 4356, Lactobacillus rhamnosus ATCC 7469 and Lactobacillus reuteri ATCC 23272, kao i komercijalnih enzima Pepsin® i Tripsin®. Procesi fermentacije i enzimske hidrolize su optimizovani sa ciljem proizvodnje hidrolizata visoke antioksidativne aktivnosti. Nakon toga izvršena je selekcija optimalnog bakterijskog soja i enzima kao i uslova izvođenja ovih procesa. Tokom selekcije praćena je antioksidativna aktivnost, sadržaj proteina i aminokiselina, stepen hidrolize, svojstvo stvaranje pene, emulgujuća svojstva, svarljivost i bioraspoloživost. Dobijeni bioaktivni hidrolizati su nakon toga sušeni, detaljno okarakterisani i u praškastom obliku dodavani u masni krem kao model konditorskog proizvoda. Tokom karakterizacije praćeni su antioksidativna, antireumatska, anti-inflamatorna i antimikrobna aktivnost, sposobnost inhibicije lipidne peroksidacije kao i stabilnost antioksidativne aktivnosti proizvedenih hidrolizata u prahu. Nakon toga, ispitana je optimalna količina hidrolizata u prahu koja može biti dodata u konditorski masni krem bez negativnog uticaja na njegova senzorna svojstva i teksturu...