Chemical composition, sensory property and glycemic response of ready-to-eat breakfast meal developed from partially milled rice

Abstract

Ready-to-eat (RTE) breakfast meals developed from brown rice milled to 9% degree of milling (DOM) were investigated for chemical composition, sensory properties, and glycemic response. A twin-screw laboratory extruder operated at 20 kg/h constant feed rate, 15.5% feed moisture, 284.5 rpm screw speed, and 176.5oC barrel temperature was used. The optimum proximate composition of the meal included 7.63% protein, 0.77% fat, 1.07 ash, 0.94% fibre and 81.62% carbohydrate with 3987.93 kCal/kg energy. The minerals were 3.5 calcium, 36.2 magnesium, 104.5 potassium, 8.4 sodium, and 223.4 mg/100 g phosphorus. Analysis showed significantly (p<0.05) higher protein, fat, ash, and energy and significantly (p<0.05) lower carbohydrate content in the RTE meal developed from 9% DOM compared to 12% DOM. The meal had higher calcium, magnesium, potassium, sodium, and phosphorus than the meal developed at 12% DOM. The meal had high sensory scores for hardness, crispiness, adhesion, fracturability, and chewiness. Conversely, they had low scores for aroma, taste, and aftertaste, except for colour, the meal served with cold, lukewarm, and warm milk differed in sensory qualities. RTE meals hydrated with cold milk were the most preferred for texture attributes. The RTE with hot and lukewarm milk had better colour, aroma, taste, and after-taste scores than those with cold milk. Significant (p<0.05) reduction in the glycemic index of the developed product was observed, due to elevated protein and crude fat content, and reduced carbohydrate content. Brown rice at 9% DOM could provide nutrient-dense RTE breakfast meals with acceptable textural characteristics and moderate glycemic index.