不同储藏条件对绿竹笋酶活性与纤维化的影响

对采收后绿竹Bambusa oldhami笋经不同的处理后,研究不同温度的储藏条件下,对绿竹笋中苯丙氨酸解氨酶（PAL）和过氧化物酶（POD）活性变化与纤维素和木质素质量分数变化规律的影响。结果表明：绿竹笋采收后,在低温储藏条件下,各处理PAL活性呈先升后下降趋势,2～3 d后PAL活性快速下降,4 d开始PAL活性变化趋缓;而常温条件下竹笋PAL活性上升得快,下降速度也快,常温条件下竹笋PAL酶的失活早于低温储藏的竹笋。储藏过程中各组POD活性迅速增加后降低,经保鲜处理后的各组竹笋POD活性增加和降低均迟于未处理的对照组;常温储藏的对照组POD采收后4 d就完全失活,常温储藏过程中竹笋纤维素和木质素质量分数增加速率比低温储藏的快。通过保鲜处理和低温条件储藏,能有效保持酶活性,延长竹笋保鲜时间,降低竹笋老化速度。图6表1参14

POD,PAL activities and fibrosis of Bambusa oldhami bamboo shoots with different storage conditions

After gathering the Bambusa oldhami bamboo shoots,we designed different treatments to storage bamboo shoots,including two storage temperatures（5 ℃ and 25 ℃）,removing or remaining bamboo shell,coating 10.0 g·kg-1 chitosan or not,and coating antistaling agent BYC or not.After different treatments,peroxidase（POD）,phenylalanine ammonia-lyase（PAL） activity,the change of cellulose,and lignin content of bamboo shoots were measured.The results showed that under the low-temperature（5 ℃） storage condition,PAL activity increased first then decreased（drop fast in 2-3 d,decline slowly after 4 d）;The PAL activity increased fast under 25 ℃,and decreased also fast,and inactivation of bamboo shoot＇s PAL under 25 ℃ is earlier than preserving under 5 ℃;The POD activity increasing and decreasing time with fresh keeping pretreatment were later than the control;The POD completely inactivated after 4 d under 25 ℃ storage temperature;The content of shoot cellulose and lignin in 25 ℃ increased faster than preserved in 5 ℃ temperature.Pretreatment and low storage temperature can keep the enzyme activity effectively and reduce the aging pace of the bamboo shoot.Ch,6 fig.1 tab.14 ref.]