小黄姜腌制过程中硬度变化及其影响因素研究

目的 以贵州小黄姜为原料,通过对小黄姜脆度、多聚半乳糖醛酸酶活性、纤维素酶活性、果胶含量、纤维素含量进行检测,研究其在腌制过程中酶活的变化对产品脆度的影响。方法 采用质构仪检测小黄姜脆度；多聚半乳糖醛酸测定以及纤维素酶的测定采用DNS比色法；果胶含量的测定采用咔唑比色法；纤维素采用称量法。结果 随着腌制时间的延长,多聚半乳糖醛酸酶和纤维素酶活性都逐渐增强,在腌制第14天,两种酶的活性均有显著增强的情况；在腌制过程中,果胶含量逐渐降低,在腌制的第14天,果胶含量下降速度加剧；在腌制过程中,纤维素含量总体是降低的,但在腌制的第7天至21天,纤维素含量出现增高情况,具体原因有待研究；腌制至35天,小黄姜质地变软,脆度劣化严重。结论 相关性分析显示,脆度与果胶含量呈现极显著正相关,脆度与纤维素之间不显著,脆度与多聚半乳糖醛酸酶活以及纤维素酶活性呈现极显著负相关。

Study on hardness change and its influencing factors of Zingiber officinale Roscoe during pickling

Objective To comprehensively analyze the factors affecting the hardness of Zingiber officinale Roscoe during pickling. Methods The hardness of Zingiber officinale Roscoe was measured by texture analyzer, The pectin content was determined by carbazole colorimetry, cellulose and ethanol insoluble matter were measured by weighing method, total acid content adopted acid-base titration method, salt content adopted indirect precipitation titration method, and DNS colorimetry was used for the determination of polygalacturonase and cellulase activity. SPSS was used to analyze the correlation between hardness change and index changes during pickling. Results The hardness of Zingiber officinale Roscoe decreased during pickling, the hardness change was negatively correlated with the content of total acid, salt and water-soluble pectin (P<0.01), and positively correlated with the the content of ethanol insoluble, cellulose, pectin (P<0.01), the increase in total acid content, salt content and water-soluble pectin content would cause the decrease of hardness of ginger, the decrease of ethanol insoluble content, cellulose content and protopectin content would lead to the decrease of hardness of ginger; there was a significant positive correlation between polygalacturonase activity and hardness (P<0.05), and there was a very significant positive correlation between cellulase activity and hardness (P<0.01). Conclusion Each influencing factor is closely related to the hardness of Zingiber officinale Roscoe decreased during pickling. The change of pectin content is the main reason affecting the hardness of ginger pickles.