Study of process model system on physicochemical properties and quality modification of instant rice flour

Abstract

即食沖泡米穀粉屬預糊化穀類製品 (pregelatinized cereal products)，其主要將穀粒、穀粉漿 (cereal paste) 以乾式預糊化：膨發 (puffing)、焙炒 (roasting) 或濕式預糊化：滾筒乾燥 (drum dry)、蒸煮或擠壓 (extrusion) 加工等方式進行糊化、乾燥、粉碎、過篩 (seive) 而得。其中膨發鎗及滾筒乾燥均為便利及節省成本之預糊化方式，因此常被用於製造即食穀類製品。本研究擬以膨發及滾筒預糊化處理製備即食沖泡米穀粉，進行 (1) 不同膨發壓力 (0,3,5,7,9,11 kgf/cm2 )，(2) 冷、熱漿入料，(3) 不同滾筒表面溫度 (115、125、130℃)，對 (4) 不同直鏈澱粉含量之國產米 (台中在來一號- TCN1、台粳九號- TK9、台中糯70- TCW70) 預糊化處理後，探討其理化特性、復水性質影響及產品混濁安定性，並以多元回歸分析建立加工參數與其吸水、溶解特性之數學模式，另以食用膠與自製膨發米穀粉 (TCW70-11 kgf/cm2 ) 改善即食沖泡米穀粉之品質。 實驗結果如下，隨膨發壓力增加，膨發米穀粉之WAI、WSI、SP、糊化度、糊精度提升，粒徑、分子量變小，離層性及混濁安定性增加。並由數學方程式WAI = 8.00100－0.233223×A+ 0.014585×T+ 0.0288663×P (r 2=0.87) 、SP = 10.70046－0.42053×A+ 0.04572×T+0.40982×P (r 2=0.84)、WSI = 7.514986－0.821779×A +0.131696×T +1.730803×P (r 2=0.87)、separation ratio = 0.538692-0.020034×A + 0.002299 T+0.049799×P (r 2=0.89)，可在加工前預估成品之復水性質及離層安定性。滾筒乾燥米穀粉呈多孔性，均完全糊化，且隨滾筒溫度增加其溶解度、糊精度、混濁安定性、離層性提升，分子量變小。並由數學方程式冷漿入料：WAI = 9.861863－0.334415A+0.087127T+ 0.039369 TS (r2=0.87)、SP = 1.101079－0.481397A+0.199154T+ 0.106375TS (r2=0.95)、separation ratio =0.562169-0.019469A+0.000952T +0.003206Ts(r2= 0.94)；熱漿入料：WSI=53.87873－2.61321A+0.21491 T+0.09996TS (r2= 0.99)、separation ratio=0.230230-0.014633A+0.001675 T+0.005635Ts (r2= 0.88)可在加工前預估成品之復水性質及離層性。 以0.2 % 關華豆膠修飾膨發米穀粉沖泡液及2 % TCW70-11kg/cm2修飾滾筒米穀粉沖泡液有良好之離層、混濁安定修飾效果及最受歡迎之整體接受性。

Instant rice flour belongs to the pregelatinized cereal products group and mainly uses the dry methods: puffing, roasting or wet methods: drum drying, steaming or extrution to carry out gelatinization, drying, grinding, sieving to obtain the cereal particles and paste. The puffing gun and drum dryer are often used to produce edible cereal products because of their low costs and easy to use. This study uses puffing and drum drying to prepare instant rice flour and examines the effects of (1) different puffing pressures (0, 3, 5, 7, 9, 11kg/cm2), (2) cold and hot slurry feed, (3) different surface temperatures, (4) amylase content of rice (TCN1, TK9 and TCW70) on the physicochemical properties, rehydration properties and product turbidity stability; and multiple regression analysis was used to set up math models of the processing effect parameter of puffing and drum drying, absorbent index, and solubility. Moreover, modify the quality of instant rice flour by adding gums and puffed TCW70 -11 kg / cm2. The results show that the WAI, WSI, SP, degree of gelatinization, dextrin content, separation ratio and turbidity stability of puffed instant rice flour increase with the puffing pressure rises, but particle size and molecular weight decrease. The products' hydration preperties and separation ratio can be estimated by three math model: WAI = 8.00100－0.233223×A+ 0.014585×T+ 0.0288663×P (r 2=0.87), SP = 10.70046－0.42053×A+ 0.04572×T+0.40982×P (r 2=0.84), WSI = 7.514986－0.821779×A +0.131696×T +1.730803×P (r 2=0.87) and separation ratio = 0.538692-0.020034×A + 0.002299 T+0.049799×P (r 2=0.89). Multiple-porous structures and completed gelatinization are found in drum dried instant rice flour, and it's WSI, dextrin, turbidity stability and separation ratio increase with surface temperature increase. The hydration preperties and separation ratio of drum dried instant rice flour also can be estimated by math modle, respectively: cold slurry feeded could be used by WAI = 9.861863－0.334415A +0.087127T+0.039369TS (r2=0.87), SP = 1.101079－0.481397A +0.199154T+0.106375TS (r2=0.95) and separation ratio = 0.562169-0.019469A+0.000952T+0.003206Ts(r2= 0.94); Hot slurry feeded could be used by WSI=53.87873－2.61321A+ 0.21491T+0.09996TS (r2= 0.99) and separation ratio =0.230230- 0.014633A+ 0.001675T+0.005635Ts (r2= 0.88). There are good separation stability, turbidity stability and most popular overall acceptance when puffed instant rice flour is modified by adding 0.2 % guan gum and drum dried instant rice flour is modified by adding 2 % puffed TCW70 -11 kg / cm2 flour.