Kunchit Judprasong

Nutrients and bioactive compounds of Thai indigenous fruits.

This study determined the nutritional potential of Thai indigenous fruits in terms of nutrients, bioactive compounds, and antioxidant activities. Three indigenous fruits were collected at two conservation areas in Kanchanaburi province, Thailand. The results showed that Phyllanthus emblica L. exhibited the highest levels of vitamin C (575±452mg/100g), total phenolics (TP) (3703±1244mGAE/100g), and antioxidant activities, as measured by DPPH, FRAP and ORAC assays. Compared to the other two fruits, Antidesma velutinosum Blume contained higher levels of most nutrients and dietary fibre (15.6±5.9g/100g), as well as carotenoids (335±98μg/100g) and phytosterols (22.1±3.9mg/100g). Spondias pinnata (L.f.) Kurz was high in total phenolics (3178±887mGAE/100g) and antioxidant activity. Moreover, high correlations were found between TP and antioxidant activities (r>0.9). These Thai indigenous fruits are potentially good sources of nutrients, bioactive compounds, and antioxidant activities. Conservation and utilisation should be promoted for food security and consumption as part of a healthy diet.

Iodine Stability and Sensory Quality of Fermented Fish and Fish Sauce Produced with the Use of Iodated Salt

Background Universal salt iodization promotes the use of iodated salt for producing industrial food products, although it might affect product quality and iodine stability. Objective To assess iodine loss during fermentation of fermented fish and fish sauces produced by using iodated salt and the effect on product sensory quality. Methods Fermented fish and fish sauces were produced with iodated rock and grain sea salts (approximately 30 ppm iodine). Fermented fish was prepared from freshwater fish mixed with salt and rice bran and fermented for 6 months at room temperature. Fish sauces were prepared by mixing anchovy with salt and fermenting either exposed to sunlight or in the shade for 12 months. Residual iodine was determined with a spectrophotometer at day 0 and months 1, 3, and 6 for fermented fish and day 0 and months 3, 6, and 12 for fish sauces. After fermentation, the products were tested for sensory acceptability by Laotian and Thai panelists (approximately 50 in each panel) after they were cooked and served in the traditional manner. Results After fermentation, the level of residual iodine was 7.61 ppm (16% loss) in fermented fish, 5.57 ppm (55% loss) in fish sauce prepared with exposure to sunlight, and 9.52 ppm (13% loss) in fish sauce prepared in the shade. Sensory qualities of the products that were produced from fortified and unfortified salts as well as dishes prepared from these products were not significantly different (p > 0.05). Conclusions It is feasible to produce fermented fish and fish sauces with iodated salt and maintain acceptable iodine levels.

A continuous-flow dialysis system with inductively coupled plasma optical emission spectrometry for in vitro estimation of bioavailability

A continuous-flow dialysis (CFD) method with on-line inductively coupled plasma optical emission spectrometric (ICP-OES) simultaneous multielement measurement for the study of in vitro mineral bioavailability was developed. The method was based on a simulated gastric digestion in a batch system followed by a continuous-flow intestinal digestion. The simulated intestinal digestion was performed in a dialysis bag placed inside a channel in a flowing stream of dialyzing solution (NaHCO3). The mineral concentrations in the dialysate were determined by ICP-OES using Y and Sc as internal standards. The pH of the dialysate was also monitored on-line to ensure pH changes similar to the situation in the gastrointestinal tract.The developed system was applied to determining the dialysability of five essential elements (Ca, Mg, P, Fe, Zn) for various kinds of foods, i.e., milk-based infant formula reference material (NIST SRM 1846), milk powder, kale, mungbean, chicken meat, jasmine rice, and Acacia pennata. The dialysis profiles of elements and pH change profiles can be useful in understanding the dialysis change and factors affecting dialysability. All studied elements were rapidly dialysed in the first 30 min of simulated intestinal digestion. It is expected that this system will be useful for estimation of dialysability and for studying the mutual effects of components in food.

Nutrients and bioactive compounds in popular and indigenous durian (Durio zibethinus murr.).

This study identified nutrients, fatty acids, bioactive compounds and antioxidant activities of two popular varieties (Mon-thong, Cha-ni) and two indigenous varieties (Kra-dum and Kob-ta-kam) of durian. Each of variety was collected from 3 gardens in Nonthaburi province, Thailand. At optimal ripeness, the edible part was separated, homogenised or freeze dried, as fresh or dry samples for further analysis using standard methods. All durian varieties contained a considerable amount of dietary fibre (7.5-9.1g/100g dry matter, DM) and high amounts of carbohydrate and sugar (62.9-70.7g and 47.9-56.4g/100g DM respectively). Cha-ni, Kra-dum and Kob-ta-kam varieties had monounsaturated (MUFA) (6.1-7.8g/100g DM)>saturated (SFA) (4.2-5.7g/100g DM)>polyunsaturated fatty acid (PUFA) (0.8-1.5g/100g DM), whereas the Mon-thong variety had SFA>MUFA>PUFA (5.1, 4.0, 1.1g/100g DM, respectively). The Kob-ta-kam variety showed greater potential for health benefits in terms of carotenoids and β-carotene (2248μg and 1202μg/100g DM respectively). Phenolic compounds and antioxidant capacity were not significantly different among each variety, though the Cha-ni variety had the lowest. This study provides data on nutrients, bioactive compounds and antioxidant activities of indigenous and popular durian varieties that could be used for consumer education as well as for incorporation into the food composition databases.

Comparison of methods for iodine analysis in foods

Spectrophotometric and ICP-MS methodology for iodine determination was compared. Samples were alkali dry-ashed, dissolved in water, and iodine assayed by spectrophotometry and by ICP-MS. Iodine content in the studied foods ranged from 3 to 1304μg/100g. There was no significant difference (p>0.05) between iodine values determined spectrophotometrically using an external calibration curve and values determined using a standard addition. Foods containing low iodine concentrations (4-25μg/100g) also showed no significant difference (p>0.05) between iodine concentrations determined spectrophotometrically and concentrations determined by ICP-MS. For food items with more than 25μg/100g, the spectrophotometric methods yielded markedly higher (p<0.05) concentrations than the standard ICP-MS method (relative positive bias 25-122%), especially in foods with high sodium and/or iron contents. A catalytic effect of sodium and iron on the Sandell and Kolthoff reaction, leading to false high values in the spectrophotometric determination of iodine was demonstrated. ICP-MS is recommended for iodine determination in foods.

Method performance study of on-line internal standard addition in inductively coupled plasma mass spectrometry

The approach of adding an internal standard to all solutions at a constant level, by on-line merging of the internal standard (steady state) and the sample solution streams, was studied for multi element determinations using inductively coupled plasma mass spectrometry. An internal standard introduction system was developed using a knotted reactor, a mixing T-piece and two peristaltic pump channels. The tube length of the knotted reactor and the wash out time were optimized for achieving the best mixing efficiency. The performance of the optimized system was compared to the traditional method of internal standard addition (batch) and checked by analysis of the NIST 8415 SRM (egg powder). The uncertainty components of the internal standard addition were also evaluated and its contribution to the combined measurement uncertainty estimated. No significant difference was found in terms of accuracy and precision between the two methods. However, the new technique was proved to be very practical, robust and less time consuming than the traditional approach.

Laboratory performance on analysis of mandatory nutrients and preparation of nutrition labelling

This study assessed the performance of 17 laboratories in Thailand in analysing mandatory nutrients in salted, fried broad bean and in using data to prepare nutrition labels. Nutrient levels in the test material, as robust mean (x(∗)) and robust standard deviation (s(∗)), were assigned in line with ISO 13528. Data obtained from the laboratories were statistically evaluated against these values. Laboratories with satisfactory, questionable and unsatisfactory results for each nutrient were identified based on robust z-score. Laboratories achieving satisfactory analytical results (z-score⩽2) were for lipid, 82%; protein, 85%; Na, 82%; Ca, 62%; Fe, 81%; ash, 70%; and moisture, 62%. Reference values for some nutrients in broad bean powder were developed using data from satisfactorily performing laboratories. Less than 20% of the laboratories demonstrated good performance in preparing nutrition labels. Common mistakes were the nutrition information format, estimation of serving size and serving(s) per package.

Inulin content of fortified food products in Thailand

This study examined inulin content in 266 samples. They were 126 dried, 105 liquid and 27 semi-solid of twelve commercial inulin fortified food products and 8 samples of natural dried sunchoke. For dried food products, inulin content ranged from 3.0 ±0.8g/100g fresh weight (FW) in milk powder to 83.7± 17.8g/100g FW in inulin powder. The levels in a descending order are the powder of inulin, weight control diet, coffee mixed, instant beverage, supplemented food products for pregnant and milk. For liquid fortified foods, inulin at the level of 0.3± 0.1g/100mL FW was found in UHT milk, and up to 13.5± 4.1g/100mL FW in weight control diet beverage. The level of 2.0-2.3g/100g FW of inulin was found in beverage with different flavours, soybean milk and fruit juice. For semi-solid food, cream yoghurt, inulin at 3.9± 1.1g/100g FW was found. A serving of most products contributes inulin at 11-33% of the recommended daily intake of dietary fibre.

Nutrients and natural toxic substances in commonly consumed Jerusalem artichoke (Helianthus tuberosus L.) tuber

This study determined nutrients, chemical contaminants, (insecticide residues and heavy metals), and natural toxic substances (nitrate, nitrite, cyanide, oxalate, phytate, and trypsin inhibitor) in tubers of Jerusalem artichokes-Kaentawan in the Thai language-grown in four major provinces in Thailand. They were purchased, prepared, homogenized, and freeze-dried for further analysis using standard methods. All Kaentawan samples contained considerable amounts of fructans and dietary fiber (15.4±0.2gand3.2±0.8g/100gfresh weight [FW], respectively), as well as potassium and iron (339±61and0.32±0.05mg/100gFW, respectively). All samples had very low amounts of insecticide residues (37 compounds), cyanide, and trypsin inhibitor, as well as Pb, Cd, nitrate, and nitrite (0.82±0.09, 0.10±0.02, 1.9-17.5, and 0.01-0.24mgkg-1FW, respectively), in addition to oxalate and phytate (14±9and0.17±0.02mg/100gFW, respectively). This studys data can be used for food composition databases and for safety consumption.

Body mass index is associated with fat mass in normal, overweight/obese, and stunted preschool children in central Thailand

BACKGROUND AND OBJECTIVES Body mass index (BMI) is widely used as a surrogate measure of adiposity. The relationship between BMI and body fatness varies by race, sex, and age and more variations have been found among children. This study investigated the relationship between BMI and fat mass among 3-5 year old children having different nutritional status. METHODS AND STUDY DESIGN A cross-sectional study was conducted in 15 daycare centers in central Thailand. 137 healthy preschool children were recruited according to their nutritional status: thin [BMI for age Z scores, (BAZ) <-2 SD], normal BMI (-2 SD<= BAZ <=+2 SD), overweight/obese (BAZ >+2 SD), and stunted [height for age Z scores < -2 SD]. Fat-free mass was determined by deuterium dilution technique. Fat mass (FM) in kilograms (TFM) and in percentage (FM%), and fat mass index (FMI, FM/height2) were calculated. RESULTS FM and FMI were the highest in the overweight/obese groups. In the thin group, girls had higher FMI compared to boys (3.2 vs 2.8 kg/m2, p<0.05). The relationship between BMI with FMI and FM differed by nutritional status. BMI was more strongly associated with FMI, TFM, and FM% in the overweight/ obese (r=0.97, 0.95, 0.80, p<0.05) and the normal (r=0.88, 0.84, 0.68, p<0.05) groups but not in the stunted group, and inconsistent in the thin group. CONCLUSIONS The inconsistency in the relationship between BMI and body fatness suggests that BMI is appropriate for reflecting adiposity in normal and overweight/obese children, but not undernourished preschool children.