Effect of various plant starches on the quality characteristics of starch-based sweetened cow milk yoghurt

A Wadehra,Ak Singh,Ma Alim

doi:10.3329/jbau.v14i1.30606

Abstract

In this study, the textural, rheological and colour properties of different starch-based sweetened cow milk yoghurt were analyzed. Stickiness increased with increased addition level of modified starch for both homogenized (-2.231 to -5.304 N) and unhomogenized (-1.505 to -4.834 N) yoghurt sample. Firmness increased linearly for unhomogenized cow milk yoghurt sample at different incorporation level (3.019 to 4.887 N) but the homogenized cow milk yoghurt samples did not shown any clear significant difference. Viscosity also increased with increased addition level of modified starch and unhomogenized yoghurt sample at different incorporation level of modified starch showed clear and significant difference from sample to sample. Firmness, stickiness and viscosity of potato starch-based cow milk yoghurt with homogenization did not show any significant difference, but unhomogenized yoghurt sample showed linear increase of viscosity and firmness that ranged from 0.213 to 0.525 Pa.s and from 2.669 to 4.014 N, respectively. Stickiness of unhomogenized sample also increased with increased potato starch incorporation level. Viscosity increased with increased corn starch incorporation for homogenized sample. The pH values were more or less similar and the colour values showed it was lightness as white for all cases. The highest incorporation level (2%) was found for corn starch followed by potato (1.5%) and modified (1.0%) starch.J. Bangladesh Agril. Univ. 14(1): 119-126, June 2016

Highlights

Milk being a product of biological origin is extremely vulnerable to attack by microbes because it is a good source of nutrients such as carbohydrate (4.5 – 5.25%), protein (3 – 4 %), fat (3 – 4.5%), minerals and vitamins but the major component of milk is water (87%) (Jones, 2002)
Cow milk wascollected from National Dairy Research Institute (NDRI), Karnal, Haryana, India; analytical grade sulfuric acid and amyl alcohol were purchased from Merck Specialities Pvt
The textural and rheological properties of modified starch-based sweetened cow milk yoghurt at different substitution levels are tabulated in Table 1 and Table 2

Summary

Introduction

Milk being a product of biological origin is extremely vulnerable to attack by microbes because it is a good source of nutrients such as carbohydrate (4.5 – 5.25%), protein (3 – 4 %), fat (3 – 4.5%), minerals (approx. 275 mg/100g) and vitamins (approx. 15 mg/100g) but the major component of milk is water (87%) (Jones, 2002). Some bacterial strains used in cultures for manufactures of yoghurt or other fermented milks are known to produce polysaccharides outside the cell wall, called exopolysaccharides. The use of such strains modifies the physical properties of the fermented milk (Bouzar et al, 1997; Hassan et al, 2001). Yoghurt manufacturing processes are a little different depending on the country It always comprises a lactic acid fermentation that brings milk to gelification due to destabilization of the protein system. Consistency of yoghurt is dependent on its structure, a protein network formed by casein micelles strings and/or clusters entrapping serum and fat globules (Kalab et al, 1983). Texture represents all the rheological and structural attributes perciptible by means of mechanical, tactile and, when appropriate, visual and auditory receptors for food products

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