Jayashree Arcot

Effect of domestic processing methods on the starch, non-starch polysaccharides and in vitro starch and protein digestibility of three varieties of rice with varying levels of amylose

The effect of processing on the in vitro protein and starch digestibility of three varieties of rice (Doongara, Inga and Japonica) with different levels of amylose was studied. The effect of heating processes on the amount of protein, amylose, total starch, and non-starch polysaccharide (NSP) and resistant starch (RS) contents was also analysed. Results indicated a highly significant increase in the protein and starch digestibilities of rice. Pressure-cooking rendered starch and protein more digestible. The levels of amylose affected the digestibility of starch, but not protein digestibility per se. Boiling and pressure-cooking caused only small changes in the total RS and NSP contents in all the three varieties but some redistribution from insoluble to soluble components was observed.

Folate assay of foods by traditional and tri-enzyme treatments using cryoprotected Lactobacillus casei

Variables affecting the efficacy of the microbiological assay of folate in foods were examined. Spinach, fortified bread and two ready-to-eat breakfast cereals were extracted with or without autoclaving and centrifugation. Autoclaving and centrifugation lowered the yield of total folate in all foods. The food sample, after digestion with protease and α-amylase was deconjugated with chicken pancreas or human plasma (tri-enzyme treatment) or simply with conjugase alone (tradition single enzyme treatment). The tri-enzyme treatment was a significant improvement over the single enzyme treatment only in fortified bread. Deconjugation with chicken pancreas gave a significantly higher folate value than did human plasma in all foods except spinach. Folate assay by cryoprotected frozen Lactobacillus casei was compared with serially sub-cultured inocula. Using the cryoprotected frozen inoculum took a shorter time, was less tedious, gave better reproducibility and was more economical than using the conventional serial culture. The effects of the size of test tubes on the growth of culture and the wavelength at which turbidity was measured to achieve maximum detection were also investigated. L.casei grew faster in small tubes than in larger ones. The absorbance peak at 540 nm was higher than that at 620 nm.

Folate retention in selected processed legumes.

The effect of soaking, boiling and pressure cooking on the retention of folates in whole chickpeas (Cicer arietinum) and field peas (Pisum sativum) was investigated. Pressure-cooking allowed significantly higher (p<0.05) retention of folates compared to boiling in both the legumes. Retention of folates in chickpeas was greater than field peas irrespective of the processing procedure used. Leaching into the cooking medium was identified to be the major cause for losses of folates during soaking and cooking. Leaching losses were greater in field peas compared to chickpeas.

Determination of folate contents in some Australian vegetables

Abstract The undeconjugated and total folate contents of 22 vegetables commonly available in Australia were assayed with Lactobacillus casei after preliminary digestion with chicken pancreas. The effect of conjugate type and extraction technique on the total folate content of two of the vegetables was also investigated. In two test samples, spinach and Chinese broccoli, deconjugation with chicken pancreas gave slightly higher, but statistically not different ( P P

Edible coating materials—their properties and use in the fortification of rice with folic acid

Abstract This study investigated the technical feasibility of adding folic acid on to rice and coating with edible polymers. The coating solutions were cast into film and their properties were investigated. A concentrated premix of rice was prepared in a rotating coating pan by spraying first with folic acid solution, and then with polymer solutions and drying. The fortified rice premixes were evaluated for washing and cooking losses. The loss of folic acid in washing was lowest in rice premixes coated with ethyl cellulose followed by pectin, composite mixtures of locust bean and other coating materials with highest loss in gum arabic coated rice. No edible polymer could satisfactorily retain folic acid during boiling in excess water. Edible polymers failed to mask the yellow color of folic acid and additional masking agent was needed. The premixes had a higher water uptake ratio than raw milled rice had. Triangle tests did not show any significant difference (α=0.05) between the sensory qualities of cooked fortified rice and raw milled rice.

Enzyme protein binding assay for determining folic acid in fortified cereal foods and stability of folic acid under different extraction conditions

The widespread fortification of cereal foods with folic acid has initiated the development of a faster, easier and more reliable method to determine folate in these foods. An enzyme protein binding assay (EPBA) kit developed by a Commercial Diagnostics Company was used for the analysis of folic acid present in folate fortified foods. The food samples were also analyzed by the microbiological assay for comparison of methods. Results from both methods showed no significant difference (p<0.05) in values and showed high correlation (r=0.89, p<0.001). However, the 95% confidence interval for the lower and upper limit of agreement was high. The addition of 1% ascorbic acid to the extraction medium offered better protection of folic acid against oxidation than foods extracted without ascorbic acid. No definite effect on the folate value was observed when extraction was carried out at two different sets of conditions, 10 min at 100 and 121 °C.

Determination of folate contents in selected Indian foods using the tri-enzyme extraction and estimated folate intakes of the population based on 24-h recall

The prevalence estimate of neural tube defects in India is restricted to some village clusters and has been reported to be 6.57–8.21 per 1,000 live births, one of the highest in the world. Dietary intake data for folate are scant and do not provide an accurate estimate because of the lack of analysed data in commonly consumed cooked/processed foods. A 24-h dietary recall survey of 200 respondents aged 17–24 years in one of the Southern states of India was used to prioritize the common foods consumed. Forty-three foods/preparations were analysed for their total folate content using the tri-enzyme extraction technique and microbiological assay using Lactobacillus casei, subsp. Rhamnosus. The mean dietary intake of the selected population was estimated to be 277 µg/day based on the analytical results obtained through this study. This value is relatively higher (2.8 times) than the calculated values reported on the intakes of the rural population (98 µg/day) reported by the National Nutrition Monitoring Bureau, India.

Characteristics of a free-standing film from banana pseudostem nanocellulose generated from TEMPO-mediated oxidation

Demand for bioplastic, especially for food packaging, increases as the consumers become more aware of the destructive effect of non-biodegradable plastics. Nanocellulose from banana pseudo-stem has great potential to be formed as a bioplastic. This study aimed to characterize the free-standing film produced from banana pseudo-stem nanocellulose that was prepared by TEMPO-mediated oxidation. The film was found containing calcium oxalate crystals, which most likely influenced the film transparency and possibly affected the contact angle and tensile strength. The film had initial degradation temperature at 205°C, the contact angle of 64.3°, the tensile strength of 59.5MPa, and elongation of 1.7%. This initial characterization of free-standing nanocellulose film showed a promising potential of TEMPO-treated nanocellulose from banana pseudo-stem as a source of bioplastic. This study could also be beneficial information for further possible modification to improve the banana pseudo-stem film properties.

Interactions between phytochemicals from fruits and vegetables: Effects on bioactivities and bioavailability

ABSTRACT The combinations of two or more phytochemicals bring about changes in the ultimate biological effects and/or the bioavailability of each component. A number of mixtures of pure bioactive compounds or phytochemical-containing plant extracts provide synergy with regard to antioxidant status, anti-inflammation, anti-cancer and chemoprevention of several oxidative stress and metabolic disorders in vitro. The biological activities of food phytochemicals depend upon their bioaccessibility and bioavailability which can be affected by the presence of other food components including other bioactive constituents. The interactions between phytochemicals during intestinal absorption could result in changes in the bioavailability of the compounds, which in turn affects the intensity of their bioactivities. This paper provides an overview of combined biological effects of phytochemical mixtures derived from fruits and vegetables with a focus on anti-oxidative, anti-inflammatory and anti-carcinogenic activities. The bioavailability impairment or enhancement caused by the co-consumption of dietary phytochemicals is also discussed. Finally, research gaps for future studies on phytochemical interactions are identified.

New data for vitamin D in Australian foods of animal origin: impact on estimates of national adult vitamin D intakes in 1995 and 2011-13.

OBJECTIVES To assess the potential dietary supply of vitamin D to Australian adults by application of new data for Australian primary foods of animal origin. METHODS New published analytical data on the vitamin D contents of Australian primary foods from animal products were obtained and assessed for reliability. Using food consumption data from Australian population dietary surveys for 1995 and 2011-2013, estimates were made of the likely average daily intakes of vitamin D equivalents from these sources by Australian adults. RESULTS Meats, chicken, fish, eggs and dairy produce may alone have contributed about 4.2 μg vitamin D equivalents per day to average Australian diets of adults >18 years in 1995 and 4.3 μg in 2011-2013. CONCLUSIONS Dietary vitamin D intake in Australia is likely to be higher than previously estimated because new data from improved analytical methods reveal the contributions to vitamin D supply from foods of animal origin. Absence of reliable vitamin D data for milk and milk products, and the gaps in vitamin D data for many commonly consumed seafood, poultry, eggs and processed animal products greatly limit estimation of dietary vitamin D intakes by Australians.