Some properties of rice grains, flour and starches: A comparison of organic and conventional modes of farming

Maninder Kaur, Navneet Kaur, Mandeep Kaur, Kawaljit Singh Sandhu

Department of Food Science and Technology, Guru Nanak Dev University, Amritsar 143005, India.

Abstract

The research focused on comparison of properties of rice grown by organic mode (OM) and conventional mode (CM) of farming. Paddy obtained from both the modes of farming was milled and studied for physicochemical, cooking and textural properties. Both the rice was then powdered to flour and their properties were compared. Starch was then isolated from both types of rice and analyzed for their amylose, swelling power, X-ray diffraction, pasting and morphological properties. Milled rice from OM farming exhibited significantly (P < 0.05) higher thousand kernel weight and length/breadth ratio but lower bulk density and protein content in comparison to rice from CM farming. Cooked rice grains from OM farming showed significantly (P < 0.05) higher elongation and width expansion ratio and lower gruel solid loss and grain hardness. Starch isolated from milled rice of CM farming showed significantly (P < 0.05) lower amylose content, pasting properties but higher swelling power and solubility in comparison to its counterpart OM starch. Both the starches showed typical A-type X-ray diffraction pattern. Scanning electron micrographs of starches from both modes of farming revealed the presence of smooth surfaced granules with polyhedral shape and a very few round shaped granules.

Keywords: Rice; Starch; Organic; Conventional; Pasting.