蒸汽爆破对不同品种米糠可溶性膳食纤维结构及特性的影响

Effects of Steam Explosion on Structural and Properties of Soluble Dietary Fiber in Rice Bran from Different Varieties

以稻花香、长粒香、赣晚籼40号3种稻谷米糠为原料,探究蒸汽爆破对不同品种稻谷米糠可溶性膳食纤维的影响。应用傅里叶变换红外光谱、X射线衍射和扫描电镜探究蒸汽爆破对米糠SDF结构的影响;以持水力、持油力、吸附胆固醇能力、吸附葡萄糖能力、α-淀粉酶活性抑制能力及抗氧化能力为评价指标,研究蒸汽爆破对米糠SDF功能特性的影响。结果表明,蒸汽爆破使米糠SDF红外光谱中部分吸收峰的吸收强度增加、结晶度降低、结构疏松多孔;稻花香、长粒香、赣晚籼40号稻谷米糠经汽爆后其SDF的含量较其对照分别增加了87.22%、94.72%、70.31%;3种蒸汽爆破米糠SDF的持水性、持油性、在人体胃液环境下吸附胆固醇能力、吸附葡萄糖能力以及对ABTS^(+)·、·OH清除率和总抗氧化能力较其对照均显著增加(P<0.05);蒸汽爆破长粒香和赣晚籼40号米糠SDF对α-淀粉酶活性的抑制能力较其对照分别增加了7.60%和21.72%。蒸汽爆破稻花香米糠SDF的持水力、吸附胆固醇的能力较强(pH2)以及对DPPH·的清除率最高,分别达到1.06 g/g、43.93μmol/g和14.25%,而蒸汽爆破长粒香米糠SDF的持油力、对α-淀粉酶活性抑制能力和总抗氧化能力最高,分别达到4.02 g/g、86.53%和3.82μmol/g;蒸汽爆破赣晚籼40号米糠SDF吸附葡萄糖的能力和对ABTS^(+)·、·OH清除率较强,分别达到625.16 mg/g、98.26%和27.85%。综上,蒸汽爆破使3种米糠SDF的含量增加,功能特性较其对照得到改善,但3个蒸汽爆破品种米糠SDF的功能特性存在明显差异。

Rice bran from 3 rice varieties,namely Daohuaxiang,Changlixiang and Ganwanxian No.40 were used as raw materials to investigate the effect of steam explosion on structural and properties of soluble dietary fiber in rice bran of different varieties.The structure alteration of SDF in rice bran treated by steam explosion was observed by Fourier transform infrared spectroscopy,X-ray diffraction and scanning electron microscopy.The impact of steam explosion on SDF functional properties of rice bran was studied by a series of evaluation indicators,such as water holding,oil holding,cholesterol adsorption,glucose adsorption,α-amylase inhibition and antioxidant capacity.The results showed that steam explosion could increase some absorption peaks intensity in the infrared spectrum of SDF,decrease crystallinity and form loose and porous structure of rice bran SDF from 3 rice varieties.The SDF contents in Daohuaxiang,Changlixiang and Ganwanxian No.40 rice bran by steam explosion were increased by 87.22%, 94.72% and 70.31%, respectively. Notably, the functional properties of steam-exploded rice bran from 3 rice varieties, such as water retention, oil retention, cholesterol adsorption capacity under human gastric fluid environment, glucose adsorption capacity, ABTS^(+) and OH free radical scavenging rate and total antioxidant capacity were significantly increased compared with control group (P<0.05). The α- amylase inhibition activity of SDF in steam-exploded Changlixiang rice bran and Ganwanxian No.40 rice bran increased by 7.60% and 21.72%, respectively. The SDF in steam-exploded Daohuaxiang No.40 rice bran showed stronger water retention, cholesterol adsorption ability (pH2) and higher clearance rate of DPPH·, which reached 1.06 g/g, 43.93 μmol/g and 14.25%, respectively. In contrast, the SDF from Changlixiang rice bran by steam explosion exhibited higher oil retention, α-amylase activity inhibition ability and total antioxidant capacity, which reached 4.02 g/g, 86.53% and 3.82 μmol/g, respectively. The SDF in Ganwanxian No.40 rice brans showed stronger ability to adsorb glucose, and the radical scavenging ability for ABTS^(+)· and ·OH was 625.16 mg/g, 98.26% and 27.85%, respectively. In summary, the SDF content in bran of 3 rice varieties by steam explosion was increased and their functional properties were improved compared with the control group, the SDF treated by steam explosion from 3 rice varieties showed different functional properties.