Nithiya Rattanapanone

Biotechnological valorization of cashew apple: a review.

Cashew apple, the peduncle of cashew fruit, is an agricultural waste byproduct from harvesting cashew nuts. Cashew apple juice contains about 10% reducing sugar. Its bagasse contains about 20% of cellulose. The byproducts can be used as a substrate for several microbial fermentation processes. Wine and bioethanol were produced by Saccharomyces cerevisiae. Probiotic beverage and lactic acid were produced by Lactobacillus casei. Biosurfactants-rhamnolipids, emulsan and surfactin were synthesized by Pseudomonas aeruginosa, Acineto- bacter calcoaceticus and Bacillus subtilis, respectively. Tannase and pectinase were produced during solid-state fermentation of Aspergillus spp. Prebiotic oligosaccharides were synthesized by the activity of dextransucrase produced by Leuconostoc spp. Cashew apple is a potential substrate for producing a variety of products, depending on the type of microorganisms used.

Optimizing Tannin Precipitation in Cashew Apple Juice

The juice extracted from cashew apples contains tannins that must be reduced due to their astringency and anti-nutritional properties. This study investigated reducing the tannins in cashew apple juice by mixing gelatin at 0.0 to 1.0% (w/v) with the juice for 5 to 15 min. Response surface methodology was used to simulate tannin concentration, turbidity, and weight of precipitate as a function of gelatin concentration and mixing time. All models were significant (P<0.01) and residuals exhibited normal distribution. Increasing the gelatin concentration decreased tannins and juice turbidity. Optimal conditions for minimum concentration of tannins and turbidity were obtained by adding gelatin at 0.67% (w/v) for 15 min. Cashew apple juice with the tannins reduced could be used in the subsequent production of wine and bioethanol.

Combined effect of calcium salt treatments and chitosan coating on quality and shelf life of carved fruits and vegetables

This study analyzed the combined effect of three types of calcium salts (CaCl2, Ca lactate, and Ca propionate) and chitosan coating on the quality and shelf life of carved fruits and vegetables (pumpkin, cantaloupe, carrot, Chinese radish, and Japanese cucumber). The best concentration of each salt was compared with chitosan (0.25 or 0.5%) coating combined with 0.5% CaCl2. The quality and shelf life of the five carved fruits/vegetables in rose-shape were investigated during storage in a clamshell container at 5±1°C. The study simulated the use of the carved samples as decorative food by transferring them daily between storage and room/display temperature (5 and 25°C). The combination of 0.5% CaCl2 + chitosan (0.25% or 0.5%) was the most effective for carved (rose shape) pumpkin, cantaloupe, and carrot. Chitosan coating helped delay dehydration and maintained the color of the carved samples better than the calcium salt alone. The shelf life of the carved (rose and carnation shapes) pumpkin and carrot was 6 and 12 days, respectively. The shelf life of the carved cantaloupe as rose and carnation shapes was 9 and 6 days, respectively; the shelf life of the carved Chinese radish (rose shape) and carved Japanese cucumber (lotus shape) was 9 and 6 days, respectively.

Prediction of Antioxidant Capacity of Thai Indigenous Plant Extracts by Proton Nuclear Magnetic Resonance Spectroscopy

Antioxidant capacities of the ethanol extracts from 28 Thai indigenous plants were determined by FCRC, DPPH, ABTS and FRAP assays. Proton nuclear magnetic resonance spectra of the extracts dissolved in D2O were mea- sured at 300 MHz. The antioxidant capacity and integrated peaks of nuclear magnetic resonance (NMR) spectra were analyzed by partial least square (PLS) regression. Linear correlation was found between the actual and predicted an- tioxidant capacities of all assays with R 2 more than 0.84 for calibration models and more than 0.54 for cross-validation models. However, these values were lower than those using infrared (IR) spectroscopy in our previous study. The lower efficiency of NMR-PLS regression might be due to the integrated NMR spectra having lower resolution than the whole IR spectra. Therefore, full NMR spectra should be further investigated for predicting the antioxidant capacity or other biochemical properties of plant extracts.

Quality Changes in Ripened Mango and Litchi Flesh After Cryogenic Freezing and During Storage

This study investigated a methodology to cease the activity of polyphenol oxidase (PPO) enzyme and peroxidase (POD) enzyme on ripened mango flesh cv. Maha Chanok and litchi flesh cv. Hong Huay before storage using liquid nitrogen. The immersion of halved-ripened mango flesh in a mixture solution of 1% citric acid and 1% calcium chloride for 2 min resulted in the optimal activity decrease of PPO and POD at 64.0 and 48.3%, respectively. Compared to the control, which was soaked in the previously stated mixture solution before freezing by liquid nitrogen and kept at -24°C for 6 months, the PPO and POD enzyme activities of the frozen ripened mango flesh only slightly increased during the storage period. The average enzyme activities in the control group were lower by 53.4 and 40.8%, respectively. In case of litchi flesh, the implementation of 0.5% calcium chloride solution for 5 min inactivated PPO and POD enzyme activities by 39.9 and 34.2%, respectively, whereas the texture of the flesh was improved, without leaving a bitter taste. In addition, the measured compression force of the litchi flesh texture, which belonged to the experimental set, was higher than the control set and differed significantly (p ≤ 0.05) from each other. When the presoaked litchi flesh in 0.5% calcium chloride solution was frozen in the liquid nitrogen and maintained at -24°C for 6 months, the firmness of frozen litchi flesh after thawing was relatively stable throughout the storage period. The activity of PPO enzyme dropped slightly, whereas POD activity only decreased during the first month and the activities increased afterwards. The activities of enzymes in the experimental set were significantly lower than the control set (p ≤ 0.05).

Physico-chemical changes during growth and maturation of tangerine fruit cv. 'Sai Nam Phueng' and 'See Thong'

Several tangerine cultivars are popular and commercially produced in Thailand. Despite this, no published data exists on the physico-chemical characteristics of the Thai cultivars, assessing their quality, throughout the various stages of fruit development. This study will assess the quality of the physicochemical characteristics of two cultivars, ‘Sai Nam Phueng’ and ‘See Thong’, during growth and maturation. Chlorophyll degradation and carotenoid accumulation in peel resulted in changing color from green to yellow-orange throughout fruit development of both cultivars. Carotenoid accumulation in juice resulted in changing color from yellow-orange to deep orange. Titratable acidity (TA) and citric acid content of both cultivars peaked at the early growth stage, then rapidly decreased during growth and slightly decreased during maturation. Malic acid and vitamin C content were very high at early growth stage, and then declined toward fruit maturation. Isocitric acid content gradually decreased during maturation. The total soluble solids (TSS), TSS/TA ratio, sucrose, glucose and fructose content rapidly increased during growth and slowly increased during maturation. During maturation, ‘Sai Nam Phueng’ had higher TA, TSS, citric acid, vitamin C, sucrose, glucose and fructose content and lower peel carotenoid, isocitric acid content, juice pH and TSS/TA ratio than ‘See Thong’. Peel and juice colors, peel chlorophyll, juice carotenoid and malic acid content did not differ between the two cultivars during maturation.