【作者】 陈瑞；

【导师】 宋伟；

【作者基本信息】 南京财经大学 ， 农产品加工与贮藏工程， 2011， 硕士

【摘要】 我国是稻米生产大国,按照目前的储藏条件储藏稻谷需要占用较大的仓容。且储运过程中运输的费用和所需的劳动力均较大,如改稻谷储藏流通方式为糙米流通方式则可以有效的解决上述问题。本文针对我国糙米储藏中出现的一些主要问题,以2009年新产粳米为试验材料,采用氮气钢瓶进行充氮气调的处理方式,将糙米储藏在设定好的不同氧气浓度、温度、水分的密闭容器中,选取糙米中还原糖、过氧化氢酶、质构和蒸煮品质来作为衡量糙米品质变化的典型指标,为大规模实仓储藏糙米提供一定的理论依据。主要的研究成果如下:(1)糙米在低氧状态下与自然条件下储藏其还原糖含量变化的差别是存在的,25℃下13.5%水分糙米在150天的储藏期内4个氧气梯度(2%、5%、8%、21%)下的糙米中其还原糖的含量均逐渐增加,分别为77%、89%、102%、132%。低氧短时间内可以有效的抑制糙米中还原糖的增加。在自然储藏条件下的14.5%水分含量的糙米在25和30℃条件下其还原糖含量在前120天储藏期内分别快速增加174%和176%,而后很快分别下降18%和27%。在较高的储藏温度下,糙米中还原糖含量变化趋势是先上升后下降。说明自然储藏条件下高水分的糙米在不同的储藏温度下,其中还原糖含量的变化趋势是不同的。(2)在150天的储藏期内,温度20℃、水分13.5%的4个氧气浓度梯度(2%、5%、8%、21%)的糙米其过氧化氢酶活性分别下降8%、10%、13%、26%。说明低氧储藏能够有效地抑制糙米中过氧化氢酶活性的下降速率。在自然储藏条件下,糙米中过氧化氢酶的活性的下降速率比低氧状态下要快许多。通过对自然储藏条件下水分13.5%不同温度条件下糙米过氧化氢酶活性变化情况来看,高温下(30℃)糙米过氧化氢酶活性的变化比低温和常温下要快许多,15℃和30℃下,糙米中过氧化氢酶活性的多重差异性水平P=0.020﹤0.05,说明两者有显著差别。15℃不同水分的糙米在自然储藏条件下过氧化氢酶活性多重差异比较的显著性水平Sig均大于0.05,说明在15℃下不同水分的糙米在150天内其过氧化氢酶活性变化影响不显著,30℃、16.5%高水分的糙米在储藏90天后其过氧化氢酶的活性仍有较大幅度的下降。说明水分和温度是影响粮食呼吸作用的主要因素,但两者并不是孤立的,二者相互影响。(3)通过对不同储藏条件下糙米的质构和蒸煮品质检测后发现,质构和蒸煮品质指标之间存在显著的相关性,具体如下:糙米的硬度、弹性与吸水率成显著的正相关。相关系数分别为0.718、0.783;弹性与膨胀率呈显著的正相关,相关系数为0.816。黏着性与米汤中的干物质呈显著的相关性,相关系数为0.716。因此,可用硬度、黏度、黏着性、弹性来评价糙米的食用品质。(4)结合Design-Expert软件分析,建立了还原糖、过氧化氢酶2个指标的数学评价模型;以还原糖为评价指标的多元线性回归方程为: Y1=+0.79453+0.02950×A+0.071750×B+0.09450×C+2.51200×A×B-0.040750×A×C-0.019250×B×C(其中A、B、C分别表示储藏的氧气浓度、温度、糙米的水分);以过氧化氢酶活性为评价指标的多元线性回归方程为: Y1=+7.33-0.16×A-0.55×B-0.64×C+0.075×A×B+0.003×A×C+0.13×B×C-0.24×A2-0.017×B2-0.24×C2(其中A、B、C分别表示储藏的氧气浓度、温度、糙米的水分)。通过软件分析可以得出,氧气浓度、温度、水分对糙米品质均有显著影响,各因素之间相互影响,其中温度和水分的交互作用对糙米中还原糖含量、过氧化氢酶活性影响极为显著。更多还原

【Abstract】 China is a big paddy producing country,in accordance with the present storage conditions,Storaging of rice needs to occupy a larger storage capacity. Also during the storage processing it required a lot in transport and labor, If it changes the way to storage rice into brown rice can effectively solve these problems. Solving the mainly questiones of brown rice in different conditions,Using the fresh brown rice gained in 2009 as material , the use nitrogen gas cylinder charging and it mainly reseach the effects of quality changes of brown rice storage during different oxygen concentration、moistrue content、temperature, selecting sugar content、the activity of catalase, texture and cooking quality as measured by changes in the quality of the typical indicators of brown rice, brown rice for large-scale implementation of storage reservoirs to provide a theoretical basis. The following are the main results:(1) Sugar content in brown rice in under hypoxic state storage and storage under natural conditions is different. With the brown rice storage atmosphere which temperature was 25℃, four oxygen concentration gradient (2%, 5%, 8%, 21%), moistrue content was 13.5%. Sugar content decreased by 8 %, 10%, 13%, 26%. Hypoxia inhibition of short brown rice can increase the reducing sugar content. Brown rice storage atmosphere which moistrue content was 14.5%,temperature was 25℃and 30℃,the reducing sugar content during storage of the previous 120d rapidly increase 174%、176%, then quickly fell 18% and 27%. At higher storage temperature, The trend of sugar content in brown rice increased and reduced quickly. Under natural conditions, high moisture storage of brown rice at different storage temperatures, the trend of reducing sugar content which is not the same.(2) In 150 days .With the brown rice storage atmosphere which temperature was 20℃,four oxygen concentration gradient (2%,5%,8%,21%), moistrue content was 13.5%.Their catalase activity decreased by 8 %,10%,13%,26%. That explained that low hypoxia could suppress the decrease of catalase activity in brown rice. In natural storage conditions, the activity of catalase in brown rice was decreased faster than that under low hypoxia. From the activity change in brown rice which storaged under natural conditions , moistrue content was 13.5% and different temperature conditions, The activity of catalase in high temperature (30℃) brown rice changed much faster than in that low temperature, Under 15℃and 30℃,the activity of catalase in brown rice multiple different level P=0.020<0.05, The difference was conspinuous . Brown rice under 15℃natural storage in different moisture content the differences between multiple levels of significance Sig>0.05, indicating that different moisture content at 15℃, Catalase activity in brown rice did not change significantly,After 90 days storage, 30℃. high moisture content such as 16.5% brown rice ,its catalase activity decreased greatly. Moisture content and temperature were the main factor of respiration. but the two are not isolated, Their affected each other .(3) From the cooking and texture quality of brown rice under different storage conditions, It could be discovered that texture and cooking quality had significant correlations, as follows:brown rice hardness, springiness length and water absorption positive related significant. Correlation coefficients were 0.718, 0.783;Brown rice springiness length and swelling positive related significant. Correlation coefficient of 0.816. Brown rice adhesiveness and dry matter of rice soup positive related significant.Correlation coefficient was 0.716. Thus,such hardness, springiness length, adhesiveness, adhesive force texture quality to assess the taste quality of brown rice was available.(4) Combined with the analysis of Design-Expert software, Established two indicators mathematical evaluation model of sugar content and catalase;The evaluation of multiple linear regression equation for sugar indicators is: Y1 = +0.79453 +0.02950*A +0.071750*B +0.09450*C +2.51200*A*B-0.040750*A *C-0.019250*B*C (where A,B,C represented the oxygen concentration, temperature, and moistrue content ); The evaluation of multiple linear regression equation for activity of catalase indicators is:Y1 = +7.33-0.16*A-0.55*B-0.64*C +0.075*A*B +0.003*A*C +0.13*B*C-0.24* A2-0.017*B2-0.24*C2(where A,B,Crepresented the oxygen concentration, temperature, and moistrue content );It could be discovered through the analysis of software that the oxygen concentration, temperature and moistrue content had significant effect on brown rice quality, Interactions between various factors,In which the interaction of temperature and moistrue content had conspicuous affected on the sugar content and catalase.activity in brown rice.更多还原