Process Standardization for the Manufacture of Shrikhand Spread

S Sarkar,S Paul,B Sikder,S Basu,R Majhi,K Sarkar,A Sur,K Chatterjee

doi:10.6000/1929-5634.2018.07.01.3

Abstract

Purpose: Shrikhand Spread, a unique sweetened fermented Indian milk product is made by separation of whey from dahi, the Indian counterpart of Western yoghurt, followed by addition of sugar. Production of dahi employing traditional method involved undefined mixed starter cultures, uncontrolled fermentation and longer production time resulting in wide variation in its chemical and microbiological qualities. In order to cater to a product with desirable properties like lower post-acidification, higher flavour profile, firm body and lower syneresis coupled with shorter production time, conjugated application of yoghurt cultures and dahi cultures were tried. Since the shelf-life of dahi is limited, conversion into shrikhand spread may be used as a tool to extend the shelf-life and therefore the market reach towards commercialization into the global market as a potential functional food. Design/Methodology/Approach: Different batches of dahi were made from homogenized (Stage I - 2500 psi, Stage II - 500 psi) and pasteurized (74-78 °C/16-19 Sec) milk, pre-adjusted to 3.15-3.20% fat and 11.40% snf with diverse starter combinations selected upon the extent of post acidification, volatile acid production, syneresis and rheological characteristics. Homogenized, pasteurized and regulated milk was further subjected to a heat-treatment (90°C/10 min) and seeded with selected starter combinations to obtain firm curd intended for shrikhand spread manufacture. Shelf-life of shrikhand spread was evaluated in terms of chemical and microbiological criteria upto 7 days of storage at 8±1°C. Findings: Starter combination of eXactDahi 2+YoFlex Express 1.0 at an incubation temperature-time combination of 45°C/5h was found most suitable for producing dahi with smooth body, higher volatile acidity and low syneresis. Utilization of dahi obtained employing the above starter combination for the manufacture shrikhand spread was suggested and the product was found to retain its goodness when stored for 7 days at 8±1°C. Originality/Value: Conjugated use of yoghurt cultures with dahi cultures was suggested to overcome the drawbacks of traditional process of dahi manufacture suitable for conversion into shrikhand spread. This dahi was found capable of enhancing its dietetic value in addition.

Highlights

Elaboration of biologically active peptides exhibiting both functional and physiological roles in vitro and in vivo by lactic acid bacteria (LAB) have been drawing serious interest for its applications in food and nutrition science [1,2] resulting in consumer’s inclination towards healthful foods [3,4].The three major Indian fermented milk products namely dahi, shrikhand and lassi, might be considered as the Western counterpart to yoghurt, quarg and stirred yoghurt, respectively
Increase in acid production by STA IDC 701 was noted with the elevation of incubation temperature (37 to 42°C) but resulted in curd with bitter or salty taste. [24] reported increase in titratable acidity, excessive proteolysis and development of bitterness in yoghurt, which is influenced by species and strain of starter culture used
Lower firmness in yoghurt made using EPS producing starter was observed than those made with non EPS producing starter cultures starter [26, 27] might be attributed to differences in the amount and molecular characteristics of EPS and their ability to interact with proteins [28]

Summary

Introduction

Elaboration of biologically active peptides exhibiting both functional and physiological roles in vitro and in vivo by lactic acid bacteria (LAB) have been drawing serious interest for its applications in food and nutrition science [1,2] resulting in consumer’s inclination towards healthful foods [3,4].The three major Indian fermented milk products namely dahi (curd), shrikhand (sweetened concentrated curd) and lassi (stirred curd), might be considered as the Western counterpart to yoghurt, quarg and stirred yoghurt, respectively. Reviewed literature indicated that functional properties of traditional dahi could be enhanced either by manipulation of fortifying ingredients of basic mix, starter combinations and incubation temperature and time coupled with the adoption of appropriate packaging material [6] and their subsequent use for the manufacture of shrikhand. Traditional method of dahi production involving natural culturing of boiled cow, buffalo or mixed milk with undefined starter cultures and uncontrolled long fermentation could not be practical for industrial production. Conjugation application of yoghurt cultures capable of elaborating exopolysaccharides (ESP) along with normal dahi cultures might result in more acceptable product in terms of body, texture and flavour and greater antibacterial activity against pathogenic organisms. Microstructural study showed that dahi made with EPS-producing strains had relatively compact linear structure with more open structure and pores having discontinuous casein matrix than the controlled dahi [10]

Methods

Results

Conclusion