Oyster shell waste has led to many problems, including displeasing odors, pollution of the seaside, and harm to the environment. Using calcined oyster shells as a natural preservative might solve the problem of oyster shell waste. We studied the use of calcined oyster shell powder (COSP) as a natural preservative for improving shrimp shelf-life over 12 days under refrigerated conditions. As compared with the control, COSP treatment effectively retarded pH change, reduced the formation of total volatile basic nitrogen, and inhibited bacterial growth during refrigerated storage. In addition, shrimp muscle lipid oxidation measured by peroxide value (PV) and thiobarbituric acid (TBA) was decreased during storage. The quality was preserved up to 12 days with 2.0–4.0% COSP treatment as compared with only 6 days for un-treated shrimp. The development of preservatives for aquatic products is expected to delay growth of and spoilage by microorganisms in the refrigerated state, thus providing more barrier protection for aquatic food safety.

Palmyra palm (Borassus flabellifer Linn.) is an important sugar-producing plant that is widely distributed in tropical Asian countries. Its jaggery and sweet sap are prevalent in Cambodia as a substitute for table sugar. They contain essential minerals, vitamins, and biological compounds. We investigated the changes in the nutritional composition, antioxidant properties, and biological activity of palm granulated sugar prepared by using three different drying–solidification processes under vacuum conditions: the drying temperature was controlled at 80 °C, 90 °C, and 100 °C, and the drying time was 60, 75, and 90 min, respectively. Palm granulated sugar contains 10 kinds of vitamins (mainly vitamin E 52.15–55.12 mg/100 g), 5-hydroxymethylfurfural (2.18 to 41.92 mg/100 g), and 38 volatile compounds that belong to the alcohol, ketones, pyrazines, acids, and phenols groups, and an aldehyde group. Moreover, palm granulated sugar exhibits a high total phenolic content (2.77–8.94 mg gallic acid equivalent/100 g), 2,2-diphenyl-1-1picrylhydrazyl (DPPH) radical scavenging activity (20.15%–37.88%), and ferric reducing antioxidant power (FRAP) value (322.68–378.23 μmol Fe2+/mL). Furthermore, palm granulated sugar-treated NIH3T3 cells showed a higher cell viability of 18.10% to 23.68%. This study confirmed that palm granulated sugar prepared at 90 °C for 75 min can have a better product quality with increased vitamin and mineral contents, antioxidant properties, and biological activity, while also being low in 5-hydroxymethylfurfural (HMF) content.

Palmyra palm syrup, produced from Borassus flabellifer flowers’ sap, is rich in nutrients and minerals and has unique flavors. This study evaluated the in vitro antioxidant activity, physicochemical characteristics, and Maillard reaction products of palmyra palm syrup prepared by thermal and ultrafiltration processes. Palmyra palm syrup prepared by a thermal process had smaller L*, b* values, and larger a* values than that prepared by an ultrafiltration process. Palmyra palm syrup contained 10 vitamins, the most abundant being vitamin E. Overall, 38 volatile compounds were found and classified into six groups in the order of alcohols > acids > ketones > sulfurs > pyrazines > phenols and aldehyde. Volatile compounds depended on concentration, temperature, and ultrafiltration process. Protein content decreased because of participation in the Maillard reaction and increased 5-hydroxymethylfurfural (HMF) and total phenolic content. The HMF content was very low (0.02–14.95 mg/100 g). The radical scavenging activity of 2,2-diphenyl-1-1 picrylhydrazyl and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) in palmyra palm syrup with thermal process was higher than with ultrafiltration. This study established that ultrafiltration pretreatment of palmyra palm syrup generated a good appearance and reduced the HMF content, however, it negatively affected the volatile compounds and physicochemical characteristics.

This study aims to investigate the physicochemical composition, textural parameters, and chemical constituent of flaky rolls incorporated with different proportions of black rice flour. According to farinographic characteristics, the addition of black rice could reduce the stability and increase the dough development time and water absorption (%). According to extensographic properties, the addition of black rice resulted in significantly different maximum resistance to extension (BU) and extensibility (cm) versus the control. With the addition of black rice in flaky rolls, the crude protein, total dietary fiber (TDF), soluble dietary fiber (SDF), and insoluble dietary fiber (IDF) were significantly improved. Glucose released was much lower with 10% and 20% black rice than the control and 5% black rice because of the higher black rice inclusion. TDF, SDF, and IDF also increased. With increasing black rice incorporation, total anthocyanin content was also increased, as was total phenolic content, 2,2-diphenyl-1-picrylhydrazyl, and oxygen radical absorption capacity. The content of asparagine, acrylamide, hydroxymethylfurfural, furfural, methylglyoxal, and glyoxal in flaky rolls was also increased. The proper content of black rice flour (5%) could significantly enhance the stability of the dough properties; control the final volume, texture, and appearance; and retain good protein and fiber composition, antioxidant capacity, and overall acceptance of the flaky roll.