不同包装方式对留胚米理化及食味品质的影响

为延长留胚米的储藏期限,本文以新鲜加工的留胚米为研究对象,采用普通、充N2、充CO2、真空和真空+脱氧剂等五种方式进行包装,探究储藏过程中留胚米水分含量、脂肪酸值、脂肪酶活和食味品质的变化。结果表明,储藏期间留胚米的水分含量呈下降趋势,而脂肪酸值显著升高；以脂肪酸值35 mg/100 g(KOH)为储藏界限,25℃和37℃下普通包装留胚米的保质期最短(均为15 d),真空和真空+脱氧剂包装的保质期最长(均为75 d)；随着储藏时间的延长,五种包装留胚米的脂肪酶活均呈先升高后降低的趋势,但是普通包装的酶活上升速度更快且峰值也更大；在食味品质方面,五种包装方式留胚米的外观、口感和综合评分均呈下降的趋势,硬度显著增大,粘度则略有增加；总体来说,真空和真空+脱氧剂包装对留胚米食味品质劣化具有更好的抑制效果。

Effect of packaging methods on the physicochemical properties and eating qualities of the rice with remained germ

To extend the shelf-life of rice with remained germ (RRg), the RRg was stored using five packaging methods, including normal package, nitrogen filling, carbon dioxide filling, vacuum package, and vacuum package coupled with desoxidant, and the moisture content, fatty acid value, lipase activity, and eating qualities of fresh-prepared RRg during storage were subsequently investigated. The results suggest that the moisture content in stored RRg decreased while the fatty acid value significantly increased. On the basis of 35 mg/100 g (KOH) for storage bound, the stored RRg showed the shortest shelf-life (15 days) using normal package method at 25 °C and 37 °C whereas a longest shelf-life was observed for vacuum package and vacuum package coupled with desoxidan (75 days). With the increasing of storge time, the lipase activity of all stored RRg showed the trend to increase at the first stage, and to decrease at the following stage. Besides, the stored RRg under normal package method had faster increasing rate of lipase activity and higher value of lipase activity than the other four packaing methods. In the case of eating qualities, all five packaging methods lowered the appearance, mouthfeel, and comprehensive evaluation of the stored RRg, but significantly improved the hardness and slightly increased the adhesiveness. Overall, these results reveal that the vacuum package and vacuum package coupled with desoxidant methods have better capability to restrain the quality deterioration of RRg during storage.