共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
为了弄清食品在超高静压下的压致升温情况,以便准确控制杀菌的加工工艺条件,本文测定了较小热损失条件下(利用聚四氟乙烯套筒模拟)食品及其成分的压致升温值并提出了预测某一食品压致升温值的方法,与实测值比较可知此方法能较好地预测其压致升温值;由热力学第一定律推导出一定压力和温度范围内某一食品的压致升温值主要取决于其初始温度和压力,并通过经验方程拟合食品的压致升温值,建立了食品压致升温值与压力和初始温度之间的关系。在100~400 MPa下温度25~55℃时较小热损失条件下对水、大豆油和橄榄油的压致升温值进行拟合,结果表明,对这三种物质拟合得到方程的回归系数依次分别为0.976、0.990和0.981,此外,将实测值和用方程拟合得到的预测值进行比较,相对误差均不超过5%,说明此方程的拟合效果较好。 相似文献
3.
4.
5.
6.
7.
Pregelatinized corn starch solutions (8% solids) were mixed with 500 ppm each of 1-hexanol, 1-decanol and D-limonene, and subjected to three treatments: control or null treatment, addition of 4%β-cyclodextrin, and addition of 4% sucrose. Samples were frozen at ?15°C, ?60°C or ?198°C, and freeze-dried at a microwave power of 10W and a cavity pressure of 1 or 2 torr. Results showed that sample composition was significant in both drying rate and volatile retention. Samples containing β-cyclodextrin had higher levels of volatile retention than other treatments, probably due to inclusion complex formation and shorter drying times. In general, samples frozen at ?15°C had higher levels of volatile retention. Freeze-drying of samples at 1 torr resulted in higher final moisture contents than at 2 torr, but no appreciable differences in volatiles. 相似文献
8.
微波强化浸取天然色素数学模型的建立 总被引:1,自引:0,他引:1
微波强化浸取所得天然色素的产率不仅与微波的辐射功率、辐射时间有关,还与溶剂量、柚皮的破碎度等因素有关。为了把所有因素都考虑进去,首先采用“黑箱方法”先建立一个与数据拟合较好的数学模型,然后再逐渐逼近实验数据,最后用现代计算机技术按最小二乘法原则处理,确定式中的待定系数值。 相似文献
9.
按照2000年中国营养学会提出的食用油脂肪酸推荐比例:饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸的质量比是1:1:1、多不饱和脂肪酸中n-6与n-3的质量比是(4~6):1,建立数学模型,并将其编程,利用Matlab数学软件计算,方便快捷地计算出同时满足以上两个条件的调和油中各原料植物油所占百分比,并得出适合煎炸的调和油、米糠调和油、高档调和油和价格最低调和油的配方。经验证配方中脂肪酸比例符合中国营养学会推荐比例,说明建立的数学模型可有效地应用于营养型植物调和油配方研究。 相似文献
10.
11.
选用5种小麦为原料,研究霉变小麦霉菌和酵母菌总数变化与品质变化及其相关性,随着霉变程度的加深,小麦籽粒霉菌和酵母菌总数与容重、千粒重、发芽率、面筋指数、面团吸水率呈极显著性负相关,相关系数分别为:-0.713、-0.928、-0.766、-0.847、-0.628;与降落数值、湿面筋含量、干面筋含量、面团形成时间、稳定时间呈显著性负相关,相关系数分别为:-0.565、-0.489、-0.564、-0.534、-0.517;与面团最大拉伸比呈显著性正相关,相关系数为0.565.并建立数学模型进行验证回归分析,得出霉菌和酵母菌总数与各品质指标的回归方程为Y=-8 323.899X千粒重+123.628X容重-11 633.727X拉伸比+16 799.679X形成时间+2 973.845X面筋指数+415.119X发芽率-1 778.245 X湿面筋含量+17 598.095,验证结果表明建立的数学评价模型具有一定的统计意义和实际意义. 相似文献
12.
13.
14.
以气调包装冷却牛肉为研究对象,研究储藏在0、5、10℃温度条件下气调包装冷却牛肉中特定腐败菌(假单胞菌)的生长变化规律。通过Matlab7.0 软件拟合不同温度条件下假单胞菌的生长情况,得到假单胞菌生长的Gompertz 模型参数;利用响应面方程建立假单胞菌生长的二级模型;由平方根方程建立了温度对假单胞菌生长动力学影响的数学模型。进而验证0~10℃低温条件下假单胞菌的生长动力学模型。结果表明:建立的Gompertz 方程拟合相关系数均在0.99 以上,二级模型偏差度和准确度均在0.90~1.05 之间,说明建立的一级和二级模型能够真实有效地预测0~10℃条件下气调包装冷却牛肉中假单胞菌的生长情况。 相似文献
15.
Process evaluation for aseptic processing of participate foods was carried out using a model food system with a bioindicator. The model food was alginate spheres in Carboxy-methyl cellulose and the bioindicator was Horseradish peroxidase. Inactivation in the system was studied to determine thermal characteristics in the range 100–130°C using TDT cans. The D-value was 4.1, 2.6, 1.4 and 1.0 min at 100, 110, 120, and 130°C, respectively and the z-value was 48.4°C. Spherical particles containing immobilized peroxidase were made with alginate and dehydrated potato. These were processed in a continuous flow system at 110, 120, or 130°C. Destruction of peroxidase was related to thermal treatment received and was used to verify numerical simulation. Results were compared with those of a simulation for particle heating. Data showed good agreement between experimental and simulated results. 相似文献
16.
基于液汽两相流质量、动量、热量守恒方程组及表征性体积单元的概念,考虑到人体-服装-环境这一体系中的对流、扩散、蒸发、毛细运动、吸附等现象,建立了人体着装传热传质过程的数学模型,得到了较为满意的结果,为利用计算机技术对此进行数值分析和模拟奠定了基础。 相似文献
17.
18.
19.