Sathira Hirun

Fruit-derived phenolic compounds and pancreatic cancer: Perspectives from Australian native fruits

ETHNOPHARMACOLOGICAL RELEVANCE Pancreatic cancer is a devastating cancer that presents late, is rapidly progressive and has current therapeutics with only limited efficacy. Bioactive compounds are ubiquitously present in fruits and numerous studies in vitro are addressing the activity of these compounds against pancreatic cancer, thus studies of specific bioactive compounds could lead to new anti-pancreatic cancer strategies. Australian native fruits have been used as foods and medicines by Australian Aboriginals for thousands of years, and preliminary studies have found these fruits to contain rich and diversified bioactive components with high antioxidant activity. Thus, Australian native fruits may possess key components for preventing or delaying the onset of tumorigenesis, or for the treatment of existing cancers, including pancreatic cancer. MATERIALS AND METHODS Numerous databases including PubMed, SciFinder, Web of Knowledge, Scopus, and Sciencedirect were analysed for correlations between bioactive components from fruits and pancreatic cancer, as well as studies concerning Australian native fruits. RESULTS In this review, we comprehensively highlight the proposed mechanisms of action of fruit bioactives as anti-cancer agents, update the potential anti-pancreatic cancer activity of various major classes of bioactive compounds derived from fruits, and discuss the existence of bioactive compounds identified from a selection Australian native fruits for future studies. CONCLUSION Bioactive compounds derived from fruits possess the potential for the discovery of new anti-pancreatic cancer strategies. Further, Australian native fruits are rich in polyphenols including some flora that contain unique phenolic compounds, thereby warranting further investigations into their anti-cancer properties.

Phenolic Compounds, Antioxidant and Anti-Cancer Properties of the Australian Maroon Bush Scaevola spinescens (Goodeniaceae)

Scaevola spinescens (Goodeniaceae) has been traditionally used by indigenous Australians to treat various ailments including cancer, thus it is necessary to identify optimum extraction conditions for bioactive components from this plant. This study investigated the effects of different extraction conditions on Total Phenolic Content (TPC), antioxidant capacity (ABTS, DPPH, CUPRAC, FRAP assays) and anti-cancer activity (MTT assay) of S. spinescens. The results showed that optimal extraction conditions for TPC using water were 80°C, 15 min and ratio of 20:1 mL/g. However, the aqueous extract prepared under optimal conditions had lower TPC and less antioxidant capacity than those of the organic solvent extracts. The acetone extract displayed the greatest TPC as well as the highest antioxidant capacity and anti-cancer activity against a panel of cancer cell lines, including cancers of the pancreas, breast, lung, brain, skin, colon and ovary. Therefore, further investigations should be conducted to identify key bioactive compounds as potential anti-cancer agents.

Physical and chemical properties of Nam Prig Noom, a Thai green-chili paste, following ultra-high pressure and thermal processes

A study of processing green-chili pastes (Nam Prig Noom) by pressurization (100–600 MPa/30–50°C/20 min), pasteurization (90°C/3–5 min) or sterilization (121°C/4 min), subsequently, their physical, biochemical and microbiological qualities as well as the sensory acceptance were assessed. It was found that pressure at low levels (100–300 MPa) could improve activities of enzyme peroxidase (POD), polyphenoloxidase (PPO) and lypoxygenase (LOX) in the chili paste by more than 100%, while pressures above 500 or 300 MPa combined with heat would significantly inactivate these enzyme activities. Both color parameters and enzyme activities illustrated that though some enzymatic browning occurred with the pressurized products indicated by b* (yellowish) parameter, the magnitude of these browning was still milder than those thermally treated products indicated by−a* (greenness) and L (lightness) parameters, presumably as a consequence of the Maillard reaction. Moreover, the sensory scores were found in accordance with color parameters, firmness and capsaicin contents.

Optimization of far-infrared vacuum drying conditions for Miang leaves (Camellia sinensis var. assamica) using response surface methodology

Far-infrared (FIR) vacuum is an advanced drying technique that has recently been applied in food processing. Optimal drying conditions for processing tea from Miang leaves using FIR vacuum drying were investigated. Response surface methodology with a central composite design was used to design, analyze, and predict the optimal time and temperature conditions for FIR vacuum drying, taking into account the physicochemical properties of Miang leaves. When the temperature increased from 50 to 65°C and the time from 60 to 120 min, the amount of epicatechin, epicatechin gallate, epigallocatechin gallate, and total catechins significantly (p<0.05) increased while the moisture content and water activity significantly (p<0.05) decreased, compared with controls. The physicochemical properties of dried Miang leaves were significantly (p>0.05) influenced by time and temperature, compared with controls. Drying conditions of 65°C for 120 min are recommended for optimization of drying.

Investigating the Commercial Microwave Vacuum Drying Conditions on Physicochemical Properties and Radical Scavenging Ability of Thai Green Tea

The effects of drying conditions using a commercial microwave vacuum dryer on the physicochemical properties and antioxidant activity of Thai green tea were investigated. Nine different drying conditions (power 3200, 3600, and 4000 Watts vs. radiation time 20, 25, and 30 min) were applied in this study. The results showed that individual catechins, their total quantities, radical scavenging ability, and moisture content were significantly affected; however, total polyphenol content and color parameters were not significantly affected by these drying conditions. Based on this data, to obtain optimal physicochemical properties of green tea, drying conditions at 3600 Watts for 30 min were recommended.