No abstract

Changes of phytochemicals and probiotic in the pressurized purple rice beverages on storage were compared with heated products. Germinated or nongerminated purple rice were used to produce the beverages which were subjected to either pressurization at 500 MPa for 20 min at 25°C or heat at 95°C for 20 min. Subsequently, encapsulated Lactobacillus casei 01 was aseptically added to the beverages which were stored at 4°C for 4 weeks. It was found that germination led to reduction of anthocyanins, phenolic compounds and antioxidant capacity, but enhanced GABA and γ‐oryzanol contents. Pressurized beverages were lighter in color than thermally treated ones; however, their color changed faster than the heated samples during storage. Phytochemicals such as anthocyanins, phenolics, and DPPH radical inhibitors in both pressurized (germinated and nongerminated) beverages had the same trends of decreasing, but GABA and γ‐oryzanol were stable on storage. L. casei 01 remained at about 8 log CFU/ml. Practical applications Compared to ordinary rice, purple rice contains higher contents of phytochemicals such as anthocyanins and phenolic compounds. In particular, germinated grains have high concentrations of health promoting aminobutyric acid and γ‐oryzanol. To enrich its health benefits, an encapsulated probiotic can be added to the processed beverages and pressurization is a promising process to preserve these phytochemicals. Currently, pressure treatment, though relatively expensive, is becoming more widely used in food manufacturing. Since its benefits in retaining important nutrients and, as this study shows, phytochemicals are significant, and justify the increased costs that health conscious consumers will pay. The increasing popularity of functional foods suggest the processes researched in this study could be easily taken up and exploited in the market place to produce high‐quality purple rice products.

Sesame and perilla seeds were analyzed for fat, protein, moisture and ash. Their mineral contents, lignan, γ-tocopherol and fatty acid profiles were also determined. The results showed that sesame seeds had higher protein, lipid and mineral contents but lower fiber contents than perilla seeds, accounting for 17.38-20.76%, 42.70-46.18%, 3.07-6.47%, 18.00-21.88%, respectively. Major minerals in the seed were 0.26-0.95% calcium and 0.11-0.23% magnesium. Perilla oil showed lower pH than sesame oil giving it higher acid value. Most lignans were more concentrated in sesame than perilla. Sesamin was the predominant lignin, followed by sesamolin. The sesamin and sesamolin contents in sesame were ranged for 148.30-183.68 mg/100g and 33.96-43.54 mg/100g, respectively. Although black sesame oil had low content of sesamin and sesamolin, it performed high physiological functions due to its high contents of γ-tocopherol and unsaturated fatty acid. Gamma tocopherol of the oils was ranged from 35.81 to 51.64 mg/100g, and perilla oil showed the highest γ-tocopherol content. Fatty acid profiles revealed that the major fatty acids in sesame oils were 44.43-47.21% linoleic followed by 36.40-38.39% oleic, 7.07-9.64% palmitic and 5.09-7.72% stearic acids, giving them high polyunsaturated fatty acids (PUFA), followed by monounsaturated fatty acids (MUFA) and saturated fatty acids (SFA). White sesame oil had higher linoleic acid but lower oleic acid than other sesame oils. Perilla oil contained high amounts of 55.27% α-linolenic followed by 19.75% linoleic, 12.70% oleic and 7.38% plamitic acids, giving it high PUFA, but low SFA and MUFA. Keywords: Chemical composition, Minerals, Fatty acid profiles, Lignans, Gamma-tocopherol