电子束辐照对留胚米理化性质及食用品质的影响

Effect of Electron Beam Irradiation on Physicochemical Properties and Edible Qualities of Rice with Remained Germ

为了减缓留胚米储藏期间的脂肪酸败,延长留胚米的储藏期限,作者利用电子束辐照处理留胚米,并考察了储藏过程中留胚米的品质变化。结果表明,经0.5 kGy电子束辐照处理后,留胚米的留胚率、碎米率以及腰爆率变化不大,脂肪酶相对酶活力下降了28.2%,当辐照剂量增至1.0 kGy后,留胚米的腰爆率显著上升;在储藏过程中,电子束处理的留胚米样品,其水分含量下降较快,而脂肪酸值增幅速率变缓;此外,未处理样品的脂肪酶相对酶活力在储藏过程中呈现出先上升后下降的趋势,而电子束处理样品的脂肪酶相对酶活力呈线性降低的趋势;25℃和37℃储藏条件下,未处理样品的保质期均为15 d,电子束辐照处理能显著延长保质期(≥60 d);在食用品质方面,0.5 kGy处理的样品在25℃储藏120 d后,其综合评分为69.9,接近相应的未处理样品(70.6),但提高辐照剂量和储藏温度均会加速留胚米的食用品质劣化。综上,电子束辐照处理是一种有效延长留胚米储藏期限的方法。

To slow down the fatty acid abortion and prolong the storage period of rice with remained germ,electron beam irradiation was used to treat the rice with remained germ and its quality changes during storage were investigated.The results showed that after 0.5 kGy electron beam irradiation,the germ retention rate,broken rice rate and waist burst rate of rice with remained germ showed little change,and the lipase activity decreased by 28.2%.When the irradiation dose was increased to 1.0 kGy,the rate of waist burst of rice with remained germ increased significantly.During storage,the moisture content of rice with remained germ treated with electron beam decreased rapidly,while the increase rate of fatty acid value slowed down.In addition,the lipase of untreated samples rised first and then decreased during storage,while the lipase activity of samples treated with electron beams linearly decreased during the process.Under the storage conditions of 25℃and 37℃,the shelf life of untreated samples was 15 d,while electron beam treatment could significantly prolong the shelf life(≥60 d).In terms of taste quality,after storage at 25℃for 120 d,the comprehensive score of 0.5 kGy treated samples was 69.9,which was close to that of the corresponding untreated samples(70.6).Increasing the radiation dose and storage temperature accelerated the deterioration of the taste quality of rice with remained germ.In conclusion,electron beam irradiation treatment is an effective method to prolong the storage period of rice with remained germ.