Properties of Sweet Buttermilk Released from the Churning of Cream Separated from Sheep or Cow Milk or Sheep Cheese Whey: Effect of Heat Treatment and Storage of Cream.

Lambros Sakkas,Panagiotis E. Igoumenidis,Vasiliki Evageliou,Golfo Moatsou

doi:10.3390/foods11030465

Lambros Sakkas, Panagiotis E. Igoumenidis + Show 2 more

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https://doi.org/10.3390/foods11030465

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Abstract

The objective of the study was to compare the buttermilk released from the churning of sweet cream separated from sheep milk (BSM) or whey (BSW) with the buttermilk from sweet cow milk cream (BCM). Additional experimental factors were the heat treatment (68 °C for 10 or 30 min) and storage of cream (refrigeration or freezing). The composition of BSM was the most advantageous in terms of non-fat solids, protein—which was the most abundant solid component—casein, calcium and phosphorus contents. No significant differences were observed in the phospholipids (PL) content of BSM, BCM and BSW. Antioxidant potential and emulsion stability (ES) of BSM were the highest. The radical scavenging activity (RSA) of BSW was high opposite to chelating activity (CA). Some functional properties of BSW were similar to those of BSM and BCM. The freezing of cream affected the churning, the fat content, the soluble nitrogenous fraction at pH 4.6 (WSN) and some functional properties of buttermilk, but not in a consistent manner. The properties of BSM were marginally affected or unaffected by the use of frozen cream. The freezing of whey cream caused significant changes (p < 0.05) in the protein profile and the functional behaviour of BSW. Cream heat treatment affected the WSN of BSW opposite to its sweet cream counterparts.

Highlights

IntroductionSweet or acidified buttermilk is the by-product of the butter making process and contains most of the ingredients of milk fat globule membrane (MFGM) and relatively small amounts of triglycerides, depending on the butter making conditions [1]
The average composition of raw sheep milk (SM) used for the preparation of cream was as follows: fat 6.21 ± 0.59%, protein 5.43 ± 0.17%, lactose 4.64 ± 0.05%, acidity 19.08 ± 1.01% lactic acid (LA) and pH 6.68 ± 0.04
The pH was not in accordance with % acidity, due to the interference of caseins in the estimation of the latter. Both the acidity and the pH of whey cream were statistically significantly lower (p < 0.05) than those of cream prepared from milk

Summary

Introduction

Sweet or acidified buttermilk is the by-product of the butter making process and contains most of the ingredients of milk fat globule membrane (MFGM) and relatively small amounts of triglycerides, depending on the butter making conditions [1]. The composition of sweet buttermilk is similar to skim milk in terms of gross composition and its major components are the non-fat components of churned cream, i.e., caseins, serum/whey proteins, lactose and minerals [2,5]. Buttermilk contains parts and components of MFGM, such as proteins and polar lipids [3,6,7,8,9,10], in quantities affected by the conditions of the heat treatment and churning of cream [2,5,11,12]

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