高温条件下挂面储藏稳定性的研究

Effect of high-temperature on storage stability of dried noodles

在高温环境下,挂面中脂质的酸败速率会增加,储藏稳定性大幅降低,从而缩短挂面的货架期。为研究高温条件下挂面的储藏稳定性,选取3种不同加工精度小麦粉(1号、2号和5号)分别添加3种添加剂(Vc+脱脂大豆粉、葡萄糖氧化酶和脂肪酶)制作挂面,以2种形式(扎孔包装和脱氧包装(阻氧型包装袋+脱氧剂+密封))包装挂面,在恒温恒湿培养箱(40℃,RH 70%)中储藏28 d,研究储藏过程中挂面脂肪酸值、丙二醛含量和感官评分的变化。结果表明:小麦粉的加工精度是影响挂面储藏稳定性的最主要因素,其加工精度越低,制作的挂面脂肪酸值、丙二醛含量就越高,货架期越短,储藏稳定性越差;即使添加少量的酶制剂(如3 mg/kg脂肪酶、10 mg/kg葡萄糖氧化酶)也会促进酸败,缩短货架期,降低挂面的储藏稳定性;小麦粉中添加30 mg/kg Vc和0.2%脱脂活性大豆粉可延长挂面的货架期,提高其储藏稳定性;与扎孔包装相比,脱氧包装可延缓挂面脂肪酸值和丙二醛含量的升高,延长其货架期,提高储藏稳定性。

In summer or high-temperature environment,the rancidity rate of lipids in dried noodles will increase,storage stability will be greatly reduced,and the shelf life of dried noodles will be shortened.In order to study the storage stability of dried noodles under high-temperature condition,three kinds of wheat flour with different milling precision(No.1,No.2 and No.5 wheat flour,which milling precision gradually decreased),and 3 kinds of additives(30 mg/kg Vc+0.2%defatted soy flour,10 mg/kg glucose oxidase,and 3 mg/kg lipase,all of additives or combinations and dosages are representative)were selected to make dried noodles.Packed in two forms(ventilated or sealed with a deoxidizer inside)and stored in an incubator at 40℃and relative humidity of 70%for 28 days,the changes of dried noodles in fatty acid value,malondialdehyde content,and sensory score during storage were investigated.The results showed that the milling precision of wheat flour was the most important factor affecting the storage stability of dried noodles.As the milling precision of wheat flour decreases,the fatty acid value and malondialdehyde content of dried noodles increased,the shelf life shortened,and the storage stability decreased.For ventilated packaging without additives,the original fatty acid values of dried noodles made by No.1,No.2 and No.5 wheat flour were 9.92,15.07 and 65.31 mg/100 g,respectively,and the malondialdehyde content was 0.057,0.072 and 0.280 mg/kg,respectively.After 28 days of storage,the fatty acid values of the samples increased to 32.44,34.39 and 135.30 mg/100 g,respectively,and the malondialdehyde content increased to 0.059,0.082 and 0.306 mg/kg,respectively.The addition of 30 mg/kg Vc and 0.2%defatted active soy flour to wheat flour extended the shelf life of dried noodles and improved their storage stability.Enzymes(such as lipase,glucose oxidase,etc.),which are mainly used to improve the color and structure of steamed bread,are not recommended to be added into the wheat flour for making noodles.A small amount of enzyme(such as 3 mg/kg lipase and 10 mg/kg glucose oxidase)also accelerated rancidity,shortened the shelf life,and reduced the storage stability of dried noodles.Compared with ventilated packaging,sealing the package with a deoxidizer inside(oxygen-barrier type packaging bag plus deoxidizer plus seal)could reduce the fatty acid value and malondialdehyde content,extend the storage time of dried noodles,and improve their storage stability.For dried noodles made by No.5 wheat flour added with lipase,after 28 days of storage,the fatty acid value of dried noodles with ventilated packaging and sealing the package increased from 295.198 and 287.361 mg/100 g to 411.257 and 382.656 mg/100 g,respectively.And for the two kinds of noodles packaged with a deoxidizer inside the fatty acid values increased by 116.059 and 95.295 mg/100 g,respectively.The content of malondialdehyde increased from 0.238 and 0.221 mg/kg to 0.319 and 0.283 mg/kg,respectively.In summry,using wheat flour with high milling precision,adding 30 ppm of Vc plus 0.2%defatted soy flour,and sealing the package with a deoxidizer inside could reduce the rancidity rate and improve the storage stability of dried noodles.