Date of Graduation

8-2011

Document Type

Thesis

Degree Name

Master of Science in Food Science (MS)

Degree Level

Graduate

Department

Food Science

Advisor/Mentor

Hettiarachchy, Navam S.

Committee Member

Gbur, Edward E. Jr.

Second Committee Member

Seideman, Steven C.

Keywords

Biological sciences; Anticancer peptide; Functional foods; Functional orange juice; Rice bran peptide; Shelf life

Abstract

Functional foods offer consumers added benefits beyond the sole nutritional content of the food. Food companies are aggressively seeking new and cheaper sources of functional ingredients. Kannan et al. (2008) characterized anticancer peptides and peptide fraction from rice bran. However, information about their application and stability in food is lacking. In this study the stability of the peptide fraction in water at pH 7.2, at pH 3.5, and in orange juice was studied. The effect of the addition of the peptide fraction on the quality parameters of orange juice including sensory was also assessed. The results showed that the peptide fraction is stable at 4°C in water at pH 3.5 and in orange juice for 42 days; however, it was not stable in water at pH 7.2. A drop in pH to 5.5 from 7.2 in water and a decrease in the amount of peptide fraction were observed after 21 days. The orange juice's pH, color, and vitamin C content were not affected by the addition of the peptide; however, the total soluble solid content was significantly lower in the control compared to the orange juice with the peptide, a possible sign for interaction of peptide fraction with the orange juice components. A triangle test and a 9-point hedonic scale test were conducted with 36 panelists on freshly prepared control orange juice and freshly prepared orange juice with peptide fraction as well as control orange juice and orange juice with peptide fraction that has been stored at 4°C for 14 days. The sensory panelists did not report any differences between the control and the peptide fraction incorporated orange juice (p=0.05838) that were freshly prepared; however, the difference in flavor was reported when stored for 14 days at 4°C. These results show that there is a potential for using orange juice as a carrier for the bioactive peptide fraction.

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