毛竹笋干加工中不同杀青方式对营养及风味物质的影响

Effects of Different De-enzyming Methods on Nutrition and Flavor Substances of the Dried Bamboo Shoots During Processing

【目的】研究在毛竹笋干加工过程中,杀青方式(蒸汽和水煮)和时间对竹笋营养和风味物质的影响,为毛竹笋干加工过程中提高笋干品质提供科学依据。【方法】分别对经过蒸汽和水煮杀青0.0(对照)、0.5、1.0、1.5、2.0、3.0、4.0和5.0 h后的毛竹笋的蛋白质、草酸、单宁、可溶性糖和总酸含量进行检测,分析不同处理时间和处理方式对毛竹笋营养和风味物质的影响。蛋白质的检测采用二辛可宁酸法,草酸的检测使用靛酚蓝比色法,单宁的检测使用分光光度计直接检测法,可溶性糖的检测使用蒽酮比色法,总酸的测定按照国家标准GB 12456—2021《食品安全国家标准食品中总酸的测定》执行,糖酸比的计算:糖酸比=糖/酸。【结果】经过杀青处理后,所有的样品蛋白质均有流失,其中水煮处理的笋蛋白质含量显著减少且与处理时间没有相关关系。蒸汽处理的笋草酸含量为0.8~1.0 mg·g^(-1),水煮处理的笋草酸含量均约为1.0 mg·g^(-1),对照含量约0.1 mg·g^(-1);蒸汽处理和水煮处理的笋单宁含量分别约为0.38 mg·g^(-1)和0.41 mg·g^(-1),对照为1.2 mg·g^(-1);且草酸和单宁含量的变化与处理时间没有相关关系。蒸汽杀青处理与水煮处理相比,能够保留更多的可溶性糖,蒸汽处理的样品可溶性糖均值为8.82 mg·g^(-1),水煮处理为6.96 mg·g^(-1),对照为18.31 mg·g^(-1);经过2种方式处理的样品总酸含量为0.1~0.2 mg·g^(-1),对照为0.84 mg·g^(-1),且也与处理时间没有明显的相关性。【结论】蒸汽杀青处理与水煮处理相比,可以保留更多的蛋白质、可溶性糖和更少的草酸和单宁。故而推测蒸汽杀青方式优于水煮杀青方式,再结合在实际生产中,蒸汽杀青的流水线可以更快、更及时地处理大量的鲜笋,减少了剥壳后鲜笋在常温条件下的放置时间,这种优势也会更明显。此外处理时间对营养和风味物质的影响不大。

【Objective】This paper aims to study on the effects of different de-enzyming methods,such as steaming and boiling,and time durations,on the nutrition and flavor substances of bamboo shoots,so as to provide scientific basis for improving the product quality in processing dried bamboo shoots.【Method】The contents of protein,oxalic acid,tannin,soluble sugar and total acids in bamboo shoots after steaming and boiling for 0.0,0.5,1.0,1.5,2.0,3.0,4.0 and 5.0 h were analyzed respectively to find out effects on Moso bamboo shoots by different time durations with various treatment methods.Protein was detected with method of BCA(bicinchoninic acid),oxalic acid was detected with method of indophenol blue colorimetry,tannin was detected with method of spectrophotometer directly,soluble sugar was detected with method of anthrone colorimetry,and the determination of total acid was carried out according to the national standard GB 12456—2021“National Food Safety Standards,Determination of Total Acid in Foods”.The calculation of sugar-acid ratio is:sugar—acid ratio=sugar/acid.【Result】After steaming and boiling,the content of protein in all sample bamboo shoots was lost,and there was no evidence to prove that the significant loss of bamboo shoot protein by boiling is strongly linked to the treatment time.The content of oxalic acid of bamboo shoots by steaming was between 0.8 and 1.0 mg·g^(-1),and that by boiling was about 1.0 mg·g^(-1),and the control was about 0.1 mg·g^(-1).The tannin content of bamboo shoots treated with steaming and boiling was about 0.38 mg·g^(-1)and 0.41 mg·g^(-1),respectively,that of the control was 1.2 mg·g^(-1).Besides,the changes of oxalic acid and tannin contents have no correlation with the treatment time.Compared with boiling,in de-enzyming,steaming can retain more soluble sugar,the average soluble sugar of bamboo shoots by steaming was 8.82 mg·g^(-1),that of boiling was 6.96 mg·g^(-1),the control was 18.31 mg·g^(-1).The total acid content of bamboo shoots treated with the two methods was 0.1-0.2 mg·g^(-1),and the control was 0.84 mg·g^(-1),which had no obvious correlation with the treatment time.【Conclusion】Compared with boiled bamboo shoots,the steamed bamboo shoots retain more protein,soluble sugar and less oxalic acid and tannin.Therefore,it can be speculated that in de-enzyming,steaming is better than boiling.Combined with the actual production,the assembly line of steaming can process more fresh bamboo shoots faster,reducing the time for the peeled fresh bamboo shoots to be placed at room temperature,which greatly hilight this advantage.Another conclusion is treatment time has little effect on nutrition and flavor substances.