Microwave (MW) Energy in Enzyme Deactivation: Stabilization of Rice Bran from Few Widely Consumed Indigenous Rice Cultivars (Oryza sativa L.) from Eastern Himalayan Range

Yen

2021

Foods

Radio frequency (RF) technology is considered as a rapid heating method. Lipase in rice bran could highly accelerate lipid oxidation. The objectives of this study were to establish the radio frequency heating conditions for lipase inactivation and to evaluate the stability and antioxidant capacity. The results showed that the suitable electrode gap for a 1 kg sample load was 6 cm, and it only took 2 min to heat rice bran from 25 °C to 100 °C. Besides, there were no significant differences in the total phenolic content, flavonoid content and color between the untreated and RF-treated group, and the DPPH free radical scavenging activity of the RF treatment reached 84.8%. The acid value, free fatty acid content and peroxide value of the RF-treated rice bran met the quality standard after 8 weeks of storage at 4, 25 and 37 °C. In summary, this study provides valuable information about the RF heating procedure, and shows the great potential of RF technology for stabilizing rice bran efficiently.

Section: Resultsmentioning

confidence: 99%

Effects of Radio Frequency Heating on the Stability and Antioxidant Properties of Rice Bran

Yen

2021

Foods

“…The phytochemical diversity among various rice cultivars worldwide may have differential activity. In our endeavour to explore the indigenous rice cultivars of this region (Begum et al ., ), we aspire to identify and quantify the bioactive phytochemicals in rice cultivars of this region, for selection of rice cultivars with increased antioxidant capacity. The study aims to identify and quantify the individual phenolic acids ( viz., ferulic, p‐coumaric, sinapic, caffeic, chlorogenic and vanillic acids) present in free and bound form in rice bran of seven most abundantly cultivated and widely consumed but unexplored rice cultivars of the region, and to assess their antioxidant capacity using the DPPH and cupric reducing antioxidant capacity (CUPRAC) assays.…”

Section: Introductionmentioning

confidence: 99%

A comparative study on free and bound phenolic acid content and their antioxidant activity in bran of rice (Oryza sativa L.) cultivars of Eastern Himalayan range

Begum

Goswami

Chowdhury

2015

Int J of Food Sci Tech

Self Cite

In our study, seven most prevailing but unexplored indigenous rice cultivars of northeast India, situated in the Eastern Himalayan Range, were investigated for their phenolic acid profile, total phenolic content (TPC) and antioxidant capacities in free and bound phenolic extracts of their bran. HPLC studies showed the presence of ferulic, p-coumaric, sinapic, caffeic, chlorogenic and vanillic acids, with ferulic and p-coumaric acids being the dominant phenolic acids in the bound form. The lower EC 50 values of the bound extracts than the free extracts suggested the better radical scavenging activity of the bound extracts. Significant correlations were observed between TPC and phenolic acid content (HPLC-DAD) of bound extracts, and between Trolox equivalents antioxidant capacity (TEAC) and phenolic acid content (HPLC-DAD) of both free and bound extracts. The findings suggest that phenolic acids in the rice cultivars investigated were exclusively present in bound form and contribute significantly towards their antioxidant capacity.Free and bound phenolic acids in rice bran A. Begum et al.

“…Rice bran is considered a healthy food, due to its high concentration of nutraceutical compounds [37]. Rice bran in fact contains about 60% of all the nutrients of the entire rice grain [4]. It incorporates around 11-17% of proteins, 12-22% of oil, 6-14% of fiber, 10-15% of moisture, and 8-17% of ash, and it is rich in micronutrients, such as vitamins, and in minerals, such as aluminum, calcium, chlorine, iron, magnesium, and manganese.…”

Section: Rice Branmentioning

confidence: 99%

“…Several techniques exist and have been studied for bran stabilization: these include parboiling, chemical methods, stove toasting methods, ohmic heating techniques, retained moisture heating, added moisture heating, dry heating under atmospheric pressure, extrusion cooking, microwave heating, and infrared heating. Many researchers agree that the most effective of the aforementioned methods is microwave heating, an inexpensive and fast method that generates a product with a low range of free fatty acid that remains stable over time [4,[38][39][40]. After stabilization, rice bran can be employed directly or can be subjected to other processes in order to obtain high-value products for food, nutraceutical or pharmaceutical industry applications.…”

Section: Rice Branmentioning

confidence: 99%

“…The by-products generated through various milling steps are husk, bran, germs, and broken rice, and they are usually discarded or used for animal feeds. Bran is the most attractive of these by-products, because even though it represents only 9% of the rice weight, it contains around 65% of the nutrients of the whole rice grain [4,5]. One of the most common uses of rice bran is the extraction of rice bran oil (RBO), which is mainly produced and consumed in Asian countries [6], where it is considered as a "healthy oil," thanks to its extraordinary proprieties.…”

Section: Introductionmentioning

confidence: 99%

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A short review of green extraction technologies for rice bran oil

Garofalo

Tommasi

Fino

2020

Biomass Conv. Bioref.

Rice is one of the most important crops throughout the world, as it contributes toward satisfying the food demand of much of the global population. It is well known that rice production generates a considerable number of by-products, among which rice bran deserves particular attention. This by-product is exceptionally rich in nutrients, since it contains a wide spectrum of macronutrients (proteins, fats, carbohydrates) as well as dietary fibers and bioactive compounds. However, rice bran is usually wasted or just used for the production of low-cost products. The lipidic fraction of rice bran contains an unsaponifiable fraction that is rich in such functional components as tocopherols, γ-oryzanol, tocotrienols, and phytosterols. This lipidic fraction can be extracted to obtain rice bran oil (RBO), a high value-added product with unique health properties as a result of its high concentration in γoryzanol, a powerful antioxidant mixture of bioactive molecules. Conventional extraction methods employ hexane as the solvent, but these methods suffer from some drawbacks linked to the toxicity of hexane for humans and the environment. The aim of the review presented herein is to point out the new green technologies currently applied for the extraction of RBO, by highlighting reliable alternatives to conventional solvent extraction methods that are in line with the twelve principles of green chemistry and a circular economy.