Publications by authors named "Prasad S Variyar"

The determination of absorbed dose in gamma radiation processed onion (treated with 20-100 Gy for sprout inhibition) during storage is an important regulatory requirement to control unfair practices. To address this problem, a microscopy based method was developed using propidium iodide (PI) staining of onion adaxial epidermis. A proportional radiation dose dependent increase in nuclei count was observed during ambient (26 ± 2 °C) and low (2 ± 1 °C) temperature storage.

View Article and Find Full Text PDF

Dip coating with pullulan and chitosan in combination with lemon peel polyphenols (LPP) was attempted for shelf life extension of raw poultry meat. Control samples demonstrated bacterial lag phase and shelf life of 1.3 and 1 day, respectively at 4 °C.

View Article and Find Full Text PDF

Microbial quality is the critical parameter determining the safety of refrigerated perishables. Traditional methods used for assessing microbial quality are time consuming and labour intensive. Thus rapid, non-destructive methods that can accurately predict microbial status is warranted.

View Article and Find Full Text PDF

Improving functional properties of biopolymers for use as environment friendly packaging is an area of current interest. Biodegradable films with improved barrier and mechanical properties were prepared from methylated guar gum. Methylation resulted in structural modification of guar gum (GG) promoting greater crystallization thereby enhancing thermal stability towards decomposition.

View Article and Find Full Text PDF

Red kidney beans are a staple pulse crop well known for its unique flavor characterized by kidney bean like, smoky, sulfury and earthy aroma notes. However, nature of compounds responsible for the unique beany odor of the cooked pulse has not been established. Steam distillation extracts of red kidney beans were subjected to Gas-chromatography olfactometry (GC-O) techniques namely detection frequency and aroma extract dilution analysis (AEDA).

View Article and Find Full Text PDF

The objective of this study was to develop biodegradable active film to improve the shelf-life of minimally processed fresh-produce. Guar gum (GG) based films with improved properties were fabricated by employing tween-80 (0.88%) as emulsifier, nanoclay (13.

View Article and Find Full Text PDF

Triterpene glycosides namely momordicoside K and momordicoside L causes bitterness in bitter-gourd thereby reducing its consumer acceptance. Reducing bitterness of the juice by addition of β-cyclodextrin (0.25-2%) was attempted and its effect on sensory quality, total phenolic content, antioxidant activity and antidiabetic potential was evaluated.

View Article and Find Full Text PDF

Volatile aroma compounds of three varieties of red kidney beans (Phaseolus vulgaris) namely Kashmiri red, Sharmili and Chitra were extracted in raw state using solid-phase microextraction (SPME) and cooked state using simultaneous distillation extraction (SDE). During cooking a significant (p<0.05) reduction in the content of several aldehydes, alcohols and terpene hydrocarbons while an increase in content of various sulfurous compounds, terpene alcohols, ketones and pyrazines was noted.

View Article and Find Full Text PDF

Glucosinolates, found principally in the plant order Brassicales, are modulated by different post-harvest processing operations. Among these, ionizing radiation, a non-thermal process, has gained considerable interest for ensuring food security and safety. In gamma-irradiated cabbage, enhanced sinigrin, a major glucosinolate, has been reported.

View Article and Find Full Text PDF

Gamma irradiation (0.5-2.5 kGy) in combination with low temperature (4-15 °C) storage was attempted to increase shelf life of ready-to-cook shredded cabbage wrapped in cling films.

View Article and Find Full Text PDF

Gamma irradiation is an effective method currently being used for microbial decontamination and insect disinfestations of foods. In the present study, mango (Mangifera indica L.) juice was irradiated at doses of 0, 1.

View Article and Find Full Text PDF

The effect of allyl isothiocyanate (AITC), in combination with low temperature (10°C) storage on post harvest quality of minimally processed shredded cabbage was investigated. An optimum concentration of 0.05μL/mL AITC was found to be effective in maintaining the microbial and sensory quality of the product for a period of 12days.

View Article and Find Full Text PDF

Guar gum based nano-composite films were prepared using organically modified (cloisite 20A) and unmodified (nanofil 116) nanoclays. Effect of nanoclay incorporation on mechanical strength, water vapor barrier property, chromatic characteristics and opacity of films was evaluated. Nano-composites were characterized using X-ray scattering, FTIR and scanning electron microscopy.

View Article and Find Full Text PDF

Gamma-radiation induced browning inhibition in minimally processed shredded cabbage stored (10 °C) for up to 8 days was investigated. γ-irradiation (2 kGy) resulted in inhibition of browning as a result of down-regulation (1.4-fold) in phenylalanine ammonia lyase (PAL) gene expression and a consequent decrease in phenylalanine ammonia lyase (PAL) activity.

View Article and Find Full Text PDF

Effect of radiation processing (0.5-2 kGy) and storage on the volatile oil constituents and glucosinolate profile of cabbage was investigated. Among the volatile oil constituents, an enhancement in trans-hex-2-enal was noted on irradiation that was attributed to the increased liberation of precursor linolenic acid mainly from monogalactosyl diacyl glycerol (MGDG).

View Article and Find Full Text PDF

Mechanical and water vapor barrier properties of biodegradable films prepared from radiation processed guar gum were investigated. Films prepared from GG irradiated up to 500 Gy demonstrated significantly higher tensile strength as compared to non-irradiated control films. This improvement in tensile strength observed was demonstrated to be due to the ordering of polymer structures as confirmed by small angle X-ray scattering analysis.

View Article and Find Full Text PDF

Guar gum hydrolyzate (GGH) modified with n-octenyl succinic anhydride (OSA) and oleic acid having induced hydrophobicity was evaluated for encapsulation of mint oil and compared with gum Arabic (GA) and GA-OSA as wall material. Spray dried microcapsules prepared with these wall materials were evaluated for qualitative changes by principal component analysis and for percent retention of mint oil during 8-week storage. Results revealed that microcapsules with GGH-OSA and GGH-oleate showed slightly lower retention of mint oil as compared to GA.

View Article and Find Full Text PDF

The antioxidant property of the 70% aqueous ethanol extract of Phyllanthus amarus roots and its ether-soluble, ethyl acetate-soluble, and aqueous fractions were investigated by various in vitro assays. The root extracts showed higher DPPH, hydroxyl, superoxide, and nitric oxide radical scavenging and reducing power activity. Among all the samples, the ethyl acetate-soluble fraction demonstrated highest radical scavenging activity and total phenolics content.

View Article and Find Full Text PDF

Spray dried microcapsules of mint oil were prepared using gum Arabic alone and its blends with radiation or enzymatically depolymerized guar gum as wall materials. Microcapsules were evaluated for retention of mint oil during 8-week storage during which qualitative changes in encapsulated mint oil was monitored using principal component analysis. The microcapsules with radiation depolymerized guar gum as wall material component could better retain major mint oil compounds such as menthol and isomenthol.

View Article and Find Full Text PDF

Unlabelled: A study of gamma-irradiated Indian medicinal plant products was carried out using electron paramagnetic resonance (EPR) spectroscopy. Improved approaches like high-power measurement, microwave saturation, and thermal behavior of the radicals were explored for detection of irradiation. Aswagandha (Withania somnifera), vairi (Salacia reticulata), amla (Emblica officinalis), haldi (Curcumin longa), and guduchi (Tinospora cordifolia) exhibited a weak singlet at g = 2.

View Article and Find Full Text PDF

Impact of radiation processing on the lipid profile of fenugreek and turmeric was investigated. Oleic and linoleic acid were the dominant fatty acids with an appreciable amount of linolenic acid in both cases. Gamma-irradiation did not bring about any significant changes in the fatty acid profile of these spices despite a high content of unsaturation.

View Article and Find Full Text PDF

Increased outbreaks of food-borne illnesses, including deaths in recent years, attributed in large part to consumption of food contaminated with Escherichia coli O157:H7, have become a worldwide concern. Food-borne illnesses constitute an unacceptable health risk demanding stringent food safety controls. Despite food irradiation being a known effective method to eliminate pathogens that are difficult to eradicate by conventional methods, consumers and industry at large have been reluctant to adopt it.

View Article and Find Full Text PDF

Glycosidically bound volatile compounds of nutmeg were identified as glyco-conjugates of p-cymene-7-ol, eugenol, methoxyeugenol and alpha-terpineol. Using phenyl-beta-glucoside as external standard the contents of these glycosidic precursors were estimated based on the measurement of TLC spot density on a densitometer. p-Cymene-7-ol rutinoside was the major aroma glycoside (3.

View Article and Find Full Text PDF

Soybean samples were treated with gamma-radiation doses between 0.5 and 5 kGy for achieving insect disinfestation and microbial decontamination. Nutritional quality of soybeans with respect to antioxidant isoflavone content was tested in radiation-treated and untreated samples.

View Article and Find Full Text PDF