Degree

Doctor of Nutrition and Food Sciences (PNFS)

Department

Nutrition and Food Sciences

Document Type

Dissertation

Abstract

There is a great demand for plant-based yogurt alternatives (YAs) due to societal prevalence of milk sensitivities and allergies as well as some consumers abstaining from animal-derived products. Producing YAs from rice flour has considerable potential because (1) rice is not a major food allergen, (2) using rice flour is more economical compared to plant milks, the main ingredient in commercially available YAs, and (3) there are no rice-based yogurt alternatives in today’s marketplace. The overall goals of this study were to develop probiotic YAs from brown and white rice flours, and to evaluate their storage stability, probiotic’s survival in simulated gastrointestinal conditions, and sensory quality.

Brown (FB) and white rice (FW) flours obtained from a high-protein rice cultivar (Oryza sativa L.) called Frontière were fermented with Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, and L. rhamnosus LGG (a probiotic) to produce FB and FW YAs, respectively. The YAs were stored at 4 °C and evaluated during 28 days for physicochemical properties, separate lactic acid bacterial (LAB) counts, and probiotic survival in simulated gastrointestinal conditions. Cow’s milk yogurt (MY) and YAs made from commercially available brown and white rice flours (CMB and CMW) served as controls. A consumer study was also conducted to compare FB and FW YAs to a commercially available oat-based YA. Consumers (n = 90) rated the YAs using 9-point hedonic and just-about-right (JAR) scales.

All treatments maintained at least 8 log CFU/g for each LAB during storage. Samples’ pH dropped significantly from 4.58 to 3.62 during storage. There was no significant difference in probiotic survivability within treatments for simulated gastric studies. However, YAs prepared from white rice flours retained significantly more probiotic counts (>7 log CFU/g) than YAs prepared from brown rice flours (

Date

7-17-2022

Committee Chair

King, Joan

Available for download on Tuesday, July 08, 2025

Share

COinS