氣變包裝與溫度對綠竹筍貯藏品質之影響

Abstract

摘要 綠竹筍（Bambusa oldhami Munro）採後生理代謝旺盛，切口褐化與品質劣變快速不耐貯藏，於室溫貯藏1日後即失去商品價值。本試驗目的為尋求適當氣變包裝技術與貯藏溫度，以延長綠竹筍儲藏時間。綠竹筍利用LDPE塑材包裝於0℃、3℃、5℃、10℃貯藏後，檢測其鮮重、總醣含量、組織截切力、粗纖維含量、切口顏色與褐化面積，皆證明低溫貯藏能有效延緩劣變。綠竹筍於貯藏10天後進行官能品評，其中於0℃、3℃可維持較佳風味，其組織細緻度與整體接受度較佳，因此再進一步比較不同塑材（LDPE、PP）配合不同包裝模式（空氣、真空）於0℃及3℃之貯藏效果。在真空包裝方面，雖可降低褐化面積，使切口色澤較佳，但由於無法經適當通透氧氣與二氧化碳，造成袋內氧氣降低（2%）且二氧化碳累積（40%），進而導致醣降解快速並使組織產生異味；在另一方面，空氣包裝則可維持較佳風味，且延緩褐化作用以3℃較佳。此外，PP塑材包裝之綠竹筍其切口表面黃化程度較LDPE高。綜合前述，使用LDPE塑材配合空氣包裝，可保持較佳品質。若於LDPE塑材包裝進行穿刺一微小孔洞以利氣體交換，則可延長貯藏時間至15天。穿孔處理之組別在鮮重、總醣含量、組織截切力方面接顯示能維持較佳品質，其中以直徑0.15 mm孔洞則能有效延緩褐化。總而言之，綠竹筍以具有一0.15 mm孔洞之LDPE塑材進行包裝並貯藏於3℃能維持最佳品質。

Summary Post harvest green bamboo shoots（Bambusa oldhami Munro）are characterized by an increased respiration and browning, storage life were lose in one day under room temperature storage. In this study, the appropriate modified atmosphere packaging condition and storage temperature to extend storage life of green bamboo shoots were investigated. Green bamboo shoots were packed with LDPE bag, after 0℃, 3℃, 5℃ or 10℃ storage, fresh weight, total sugar content, cutting force, total fiber content, color value and browning area were examined, all these results prove that low temperature storage could reduce decay. Sensory evaluation were perfomred after 10 days storage. 0℃and 3℃ storage, it provide better flavor, tender texture and high consumer acceptance. Moreover, the effect of LDPE and PP packaging combined with different package model（air、vacuum）were investigated. Althogh the vacuum packaging could reduce color change and browening, however the atmosphere filtration could not perforem effectivily, result in low O2 （2%）and high CO2 concentration（40%）in bag than cause rapid sugar degradation and off-flavor. On the other hand, air packaging could maintain better flavor and 3℃ storage reduce browning better. Beside, PP packaging was more yellowing than LDPE packaging. The microperforated on package can improve gas excahge, and extend storage life to 15 days. The examination on fresh weight, total sugar content and texture were illustrated that microperforated could maintain better quality, especially with 0.15 mm penetration. In conclusion, package with LDPE bag combine 0.15 mm penetration and store in 3℃ is the best condition of green bamboo shoots storage.