Rheology and Texture of Set Yogurt as Affected by Inulin Addition

Abstract

The effect of inulin addition on rheology and texture of nonfat yogurt (NFY) was studied by the large (texture analyzer) and small (dynamic oscillatory rheometry) deformation tests. Skim milks (12% solids) were supplemented with three commercial chicory inulins with different chain lengths at 4% level and inoculated with mixed cultures of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. Textural and rheological tests were conducted after an overnight storage at 4C and during a shelf life of 28 days. A good correlation was observed between the two tests. During storage, all inulin‐containing yogurts in comparison with the control NFY were characterized by lower values of firmness, apparent viscosity, yield stress, complex viscosity, storage modulus and loss modulus. NFYs supplemented with long‐chain inulin demonstrated a rheological behavior closer to that of control full‐fat yogurt. PRACTICAL APPLICATIONS The use of inulin and oligofructose in the food industry has grown recently because of their interesting nutritional and technological properties. In the work presented here, three commercial inulin products with different chemical composition and functions were added to yogurt milk, and changes in rheological properties of yogurt were investigated in comparison with nonsupplemented control yogurts. According to the manufacturer's specifications, Raftiline HP and Raftiline GR are suitable for fat replacement because of the presence of long‐chain inulins, while Raftilose P95, being rich in mono‐ and disaccharides, is highly recommended for sugar replacement. The knowledge obtained from this study may be applied for the development of nonfat yogurts to satisfy the nutritional expectations of ever‐increasing health conscious consumers and at the same time to match the sensory and textural characteristics of full‐fat yogurt.

Influence of variable water-soluble soy extract and inulin contents on the rheological, technological and sensory properties of grapeflavored yogurt-like beverages made from caprine milk

“…This thixotropic effect occurs as a result of structural breakdown and can be estimated by considering the area of the hysteresis loop between the two curves [26]. Similar results have been reported for dairy fermented beverages [27][28][29] and for fermented beverages made from WSSE [6]. According to Mohameed et al [30], the interactions present in a network of curds include electrostatic and hydrophobic forces that are considered weak bonds.…”

Iogurte probiótico com frutanos tipo inulina de diferentes graus de polimerização: características físico-químicas e microbiológicas e estabilidade ao armazenamento

“…A longa cadeia polissacarídica dessa inulina pode ter permanecido dispersa dentro das micelas de caseína, interferindo na formação da matriz protéica e sendo responsável por um gel mais macio (PASEEPHOL; SMALL; SHERKAT, 2008). Segundo Paseephol, Small e Sherkat (2008), o mesmo pode ser observado em iogurtes integrais, nos quais os glóbulos de gordura ficam dispersos dentro das micelas de caseína ocasionando a formação de géis menos firmes.…”

Characterization of goat milk and potentially symbiotic non-fat yogurt

“…Inulin seems particularly suitable as a fat replacer in low-fat dairy products since it may contribute to an improved mouthfeel. Guggisberg et al (2009), Guven et al (2005, Kip et al (2006) and Paseephol et al (2008) showed that inulin addition to lowfat yogurt resulted in enhanced creaminess. When inulin is added to food in low concentrations, the rheological properties and the sensory quality of the product will not be affected When choosing the appropriate method of skimming, it was taken into account that the fat content (by Gerber) (Association of Official Analytical Chemists, 1998) was not higher than 0.5 g/100 mL of milk; and lipolysis was lower than 1.82 µeq FFA (Free Fatty Acids)/mL of milk since higher values may result in unwanted tastes like stale, soapy, or bitter (Deeth, 2006).…”