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Objective: To identify and quantify the bioactive compounds, along with biological activities, of native Thai edible Zingiberaceae. Methods: The bioactive compounds evaluated were phenolic acids, flavonoid, vitamin C, curcumin, 6-gingerol, eugenol and essential amino acids; analyses involved HPLC and LCMS/MS. Antioxidant activities were assessed by DPPH and FRAP assays. Results: Zingiber officinale was the richest source of bioactive compounds, followed by Z. officinale, Alpinia zerumbet and Alpinia conchigera. Total phenolic content and total flavonoid contents ranged widely across these species (17 to 200 mg GAE/100 g DW and 17 to 66 mg RE/100 g DW). All the species studied possessed strong antiglycation properties, ranging from 82 to 98%, with strong positive correlations of total phenolic content and antioxidant activity. The contents of curcumin, 6-gingerol, eugenol and vitamin C were in the range of 1 to 26, 1 to 140 µg/ g DW, 5 to 1600 and 4 to 21 mg/100 g DW, respectively. Seven essential amino acids identified by using LCMS/MS were found in most samples studied ranging from 2 to 6752 µg/100 g DW. Conclusion: Z. officinale is an abundant source of bioactive compounds and antioxidant activity in all these samples. These plants are fresh sources for developing novel functional ingredients in either food or cosmetics.

Microbial oil is one of alternative sources for biofuel and value-added chemical production in biorefining process of lignocellulosic biomass. The bottleneck of this process is the low conversion rate of lignocellulose biomass to the target product. This research aims to optimize microbial oil production as raw material for biorefining process from agricultural waste by using Plackett–Burman (PB) design and Response Surface Methodology (RSM). Acid-hydrolysates of cassava pulp and sugarcane bagasse were converted to bio-oil by fermentation activities of two oleaginous yeasts, designated as MSU2 and Ka28. The fermentation parameters were screened by PB design to identify their impacts on oil yield, and the condition of each parameter was optimized by RSM to maximized oil yield. The predicted optimal condition obtained from RSM provided the highest lipid yield at 34.56 and 21.85% from hydrolysates of cassava pulp and sugarcane bagasse, respectively. Then, fatty acid compositions in oil were analyzed by GCMS, and our results demonstrated that palmitic acid and oleic acid were the major constituents at 72.95 and 195.01 mg/g-crude lipid, respectively. These fatty acid distribution profiles were suitable for application in biodiesel production and suggested the utilization of agricultural waste in biorefining process.

This study aims to examine the pathogenic bacterial contaminations in foods sold in hospital cafeteria. A study was conducted between April and September of 2008 using cafeteria located in Mahasarakham provincial hospital, Thailand, as a study area. The cafeteria foods were evaluated for contaminations with Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Streptococcus faecalis, which have been earlier reported to cause nosocomial outbreaks. Of 33 different types of ready-to-eat foods, the majority (54.54%) were found to have bacteria >10(7) colony forming units per gram of food (cfu g(-1)), whereas 36.36% and only 9.10% of them were found to have bacteria at 10(6)-10(7) and <10(6) cfu g(-1), respectively. In addition, most of ready-to-eat foods were also shown to be contaminated with Escherichia coli (57.57%), followed by Streptococcus faecalis (51.51%), Staphylococcus aureus (48.48%) and Salmonella typhimurium (27.27%), respectively. In contrast, of 7 different types of freshly-made foods, the majority (71.42%) were found to have bacterial <10(6) cfu g(-1). Staphylococcus aureus was the most commonly found bacteria in freshly-made foods (42.85%), followed by Escherichia coli and Streptococcus faecalis at equal percentages (14.28%). None of the freshly-made foods were found to be contaminated with Streptococcus typhimurium. The results concluded that a number of ready-to-eat foods sold in the Mahasarakham hospital cafeteria were contaminated with several pathogenic bacteria at unacceptable levels. Healthcare authorities should be more aware that ready-to-eat cafeteria foods that are heavily contaminated with pathogenic bacteria may be harmful to healthcare workers and visitors and may result in nosocomial infections of the patients.