Semester of Graduation

Spring 2018

Degree

Master of Science (MS)

Department

Animal Sciences

Document Type

Thesis

Abstract

Yogurt has been recognized as a healthy food. Nutritional value of yogurt can be increased with the addition of aloe vera juice (AVJ) and inulin. People are interested in consuming products without artificial ingredients and with high content of bioactive compounds. The aims of this study were to develop a functional plain yogurt enhanced with inulin and AVJ, to evaluate the physicochemical properties, the enumeration of Streptococcus thermophilus and Lactobacillus bulgaricus, inulin content, and consumer acceptability. Six treatments were evaluated at day 1, 7, 14 and 30 at 4°C. Treatments were prepared using 2% fat milk, ABY culture, 5 and 15% of AVJ, and 1.5 % of inulin. Yogurts were analysed for syneresis, pH, color, titratable acidity (TA), viscosity, inulin content, enumeration of starter cultures. A consumer test was also conducted. Triplicate experiments were conducted, data were analyzed at α= 0.05 using a factorial arrangement with repeated measures in time. Results show pH decreased and TA increased over time. Addition of inulin and increase levels of AVJ decreased pH and TA. Luminosity (L*) was reduced significantly (PStreptococcus thermophilus counts increased (P9 CFU/g. Lactobacillus bulgaricus counts decreased at day 14 and increased significantly at day 30 with values higher than 106 CFU/g. Inulin content decreased over time. The treatment with 15% AVJ had the lowest inulin content. For sensory evaluation, treatments had significantly lower sensory scores. Purchase intent increased after the consumers are made aware of the health benefits. The study demonstrated that use high concentration of AVJ in combination with inulin negatively affect important properties in yogurt; however, yogurt can be fortified with inulin and low concentrations of AVJ to provide health benefits.

Date

4-4-2018

Committee Chair

Boeneke, Charles

DOI

10.31390/gradschool_theses.4688

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Dairy Science Commons

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