低温解除后大米储藏品质的变化及相关性分析

Storage Quality Changes and Correlation Analysis of Rice after Low Temperature Released

摘要:

为研究低温解除后大米储藏品质的变化规律，模拟我国大米主消费区的环境条件（35 ℃，80% RH和30 ℃，70% RH），并以常温储藏为对照，进行贮藏试验。通过测定丙二醛含量、脂肪酸值、降落数值、电导率、过氧化物酶活性等储藏品质指标探讨低温解除后大米品质的变化规律，并对各指标之间及其与食味值的相关性进行分析，建立食味值预测模型。结果表明：低温储藏解除后大米多酚氧化酶活性和过氧化物酶活性随着时间的延长均逐渐减小；脂肪酸值、电导率和降落数值则呈现逐渐升高的趋势；丙二醛含量变化不稳定，先升高后降低。高温高湿（35 ℃，80% RH和30 ℃，70% RH）条件下品质指标变化速率相对较快，不宜于大米的储藏；在35 ℃、80% RH和30 ℃、70% RH和常温条件下大米的货架期分别为75 d，100 d和175 d。对建立的大米储藏品质预测模型进行验证，验证试验表明所建模型是可靠的。

Abstract:

In order to investigate the quality changes of rice after low temperature storage, the quality indexes, such as malondialdehyde content (MDAC), fatty acid value (FAV), falling number, electrical conductivity rate (ECR), peroxidase (POD) and polyphenoloxidase (PPO) were measured for samples stored in the stimulated high temperature environments of the typical rice storage areas in China (35 ℃, 80% RH and 30 ℃, 70% RH), and rice stored at ambient temperature was used as the control. Then the correlation between quality indexes and eating quality of rice were analyzed and a prediction model for eating value was established. The results showed that after low temperature storage was released, the activity of POD and PPO decreased with the time prolonging, while the FAV, ECR and the falling number increased. The MDAC of rice increased at first and then decreased. Under the stimulated conditions, the rice quality changed fast, which was not suitable for rice storage. The shelf-life of rice in the 35 ℃ with 80% RH, 30 ℃ with 70% RH conditions and ambient temperature was 75 d, 100 d and 175 d, respectively. The verification test of rice quality showed that the model was credible.