Effect of the Addition of Milk Protein Preparations on Selected Quality Parameters and Nutritional Characteristics of Kefir

Małgorzata Ziarno,Rozeta Hasalliu,Angelika Cwalina

doi:10.3390/app11030966

Małgorzata Ziarno, Rozeta Hasalliu + Show 1 more

Open Access

https://doi.org/10.3390/app11030966

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Abstract

The aim of this study was to evaluate the effect of the addition of various milk protein powder preparations (MPC-80, WPC-70, sweet whey, non-demineralized or demineralized whey, whey permeate, rennet casein, buttermilk) to selected quality parameters and digestibility of milk proteins in kefir. Kefir samples analyzed in the study were prepared under laboratory conditions with three industrial bacterial starter cultures. They were examined microbiologically (lactobacilli, lactococci, yeast) and for pH, total protein content, hardness, adhesiveness, water-holding capacity (WHC), and protein digestibility (using two in vitro methods along with the determination of the content of available lysine and glycine). The counts of lactococci and lactobacilli were estimated at levels above 7 and 6 log(CFU/mL), respectively. Yeast was not found in the kefir samples. The pH value of the samples was 4.4–5.2. The pH, hardness, adhesiveness, and WHC were dependent on the type of kefir starter culture and the type of milk protein powder added. Each protein preparation added increased the amount of available lysine and glycine. However, when converted for 1 g of kefir protein, the changes in the content of available lysine and glycine were variable and depended on both the milk protein powder and starter culture used.

Highlights

IntroductionTraditionally made using cow’s milk or goat’s milk, originated from parts of Eastern Europe and Southwest Asia, which is usually produced using kefir grains or starter cultures containing the microflora that are necessary for carrying out lactic and alcoholic fermentation characteristic of kefir formation (i.e., lactobacilli, lactococci, yeasts, or sometimes acetic acid bacteria) [1,2,3]
Kefir is fermented milk, traditionally made using cow’s milk or goat’s milk, originated from parts of Eastern Europe and Southwest Asia, which is usually produced using kefir grains or starter cultures containing the microflora that are necessary for carrying out lactic and alcoholic fermentation characteristic of kefir formation [1,2,3]
This study aimed to evaluate the effects of the addition of various forms of milk proteins, including milk protein concentrates (MPCs), whey protein concentrates (WPCs), demineralized or non-demineralized whey, sweet whey, whey permeate, rennet casein, and buttermilk powders, on selected quality parameters and the digestibility of milk proteins in kefir

Summary

Introduction

Traditionally made using cow’s milk or goat’s milk, originated from parts of Eastern Europe and Southwest Asia, which is usually produced using kefir grains or starter cultures containing the microflora that are necessary for carrying out lactic and alcoholic fermentation characteristic of kefir formation (i.e., lactobacilli, lactococci, yeasts, or sometimes acetic acid bacteria) [1,2,3]. In addition to the use of skimmed milk powder (SMP) or concentration of the processing milk in a vacuum evaporator, other forms of milk proteins, such as milk protein concentrates (MPCs) or whey protein concentrates (WPCs) are used to increase the solid content of the milk base. Each of these additives produces a different effect on the quality and nutritional characteristics of fermented milk.

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