双孢菇高氧动态气调保鲜参数优化

Parameter optimization of high O_2 dynamic controlled atmosphere storage of agaricus bisporus

为提高双孢蘑菇保鲜效果,在(2±1)℃下采用高氧动态气调方法对双孢蘑菇进行贮藏试验,选取第1阶段不同O_2/CO_2比例的气体组分、换气时间、第2阶段不同O_2/CO_2比例的气体组分作为影响因素,考察双孢蘑菇贮藏过程中总色差ΔE、硬度以及感官品质的变化,对双孢蘑菇的动态气调参数进行优化。研究结果显示,第1阶段O_2比例高于80%时,可显著抑制双孢蘑菇ΔE的上升(P<0.05);第2阶段80%O_2+20%CO_2气体组分,可使双孢蘑菇的ΔE显著低于其他处理,硬度显著高于其他处理(P<0.05);而换气时间则影响较小。最优的动态气调条件为:第1阶段气体组分100%O_2,第3天换气,第2阶段气体组分80%O_2+20%CO_2,双孢蘑菇的ΔE、硬度值和感官品质评分分别为:19.40、6.84×105 Pa和9.52。将此最优动态气调运用于双孢蘑菇的保鲜,研究发现,与静态气调相比,该动态气调显著抑制了双孢蘑菇的呼吸速率与膜结构的损坏,维持了较高的过氧化物酶、抗坏血酸过氧化物酶活性与较低的多酚氧化酶活性,有效抑制了贮藏过程中的酶促褐变,保持了较高的可溶性蛋白含量,并延长其保鲜期至28 d,提高了双孢蘑菇的耐贮性。

Agaricus bisporus is highly perishable due to its thin protective structure,which could protect it from physical and microbial attack.Meantime,the high metabolism of white mushroom could accelerate the progress of senescence including water loss,cap opening and enzymatic browning,and damage its nutrition value and commercial quality seriously.It only has a short shelf life of 3-4 days at ambient temperature after harvest.Thus,an effective storage method plays an important role in mushroom industry.In this study,dynamic controlled atmosphere（DCA） was used to extend the shelf life of white mushroom.Several studies had confirmed that DCA performed well in some fruits and vegetables storage.Compared with traditional controlled atmosphere,DCA is a technique that periodically changes the ambient gas of products.It is designed to provide an optimal storage condition in different storage periods,aiming at improving the quality of products and preventing the development of physiological disorders.In this study,white mushrooms were stored at（2±1） ℃ and the first-stage gas（100% O_2,90% O_2＋10% CO_2,80% O_2＋20% CO_2,70% O_2＋30% CO_2）,transaired time（2nd,3rd,4th and 5th day） and second-stage gas（100% O_2,90% O_2＋10% CO_2,80% O_2＋20% CO_2,70% O_2＋30% CO_2） were determined as a single factor on the effect of ΔE,firmness and sensory value.Meantime,white mushroom storage conditions were optimized for orthogonality,and the physiological and biochemical quality changes under optimal storage condition were obtained during storage of white mushroom by using conductivity meter,O_2/CO_2 analyzer and other equipments.Under the condition of a single factor,the ΔE,firmness and sensory value were determined and the appropriate first-stage gas of 100% O_2,90% O_2＋10% CO_2,80% O_2＋20% CO_2,transaired time of 2nd,3rd and 4th day and second-stage gas of 100% O_2,90% O_2＋10% CO_2,80% O_2＋20% CO_2 were employed in orthogonality.The best condition of orthogonal optimization was 100% O_2 first-stage gas,transaired time 3rd day and 80% O_2＋ 20% CO_2 second-stage gas.The ΔE,firmness and sensory value in this condition was 19.40,6.84×105 Pa and 9.52 respectively.The results showed that the first-stage gas whose O_2 fraction above 80% could inhibit the increase of ΔE significantly（P〈0.05）.The 80% O_2＋20% CO_2 second-stage gas treatment retained significant（P〈0.05） lower ΔE and higher firmness than that of other treatments.The transaired time had no significant effect on the quality of mushrooms（P〈0.05）.During storage of orthogonal optimization,compared with static controlled atmosphere（SCA）,DCA could inhibit the decrease of soluble protein content of white mushroom significantly（P〈0.05） and retain its good nutrient quality.Meantime,it suppressed the respiration rate and retained certain cell membrane integrity,then further slowed down the senescence of white mushrooms.In addition,white mushroom stored in DCA had moderate peroxidase（POD）,higher ascorbate peroxidase（APX） and lower polyphenol oxidase（PPO） activity than those stored in SCA,indicating that DCA is potential to slow down the progress of enzymatic browning.In this study,DCA treatment preserved relative good quality of white mushroom during storage and extended its storage time to 28 d,confirming that DCA is a suitable method for white mushroom storage and a potential technique for fruits and vegetables storage.