参薯粉浆酶法水解条件优化与动力学分析

采用液态高温α-淀粉酶水解参薯粉浆,分别通过单因素和正交试验,检测水解液中总还原糖的含量,考察和优化参薯粉浆酶法水解液化过程,并进行酶解反应动力学分析。结果表明：酶解温度90℃、粉浆pH值5.6、参薯粉浆质量浓度40mg/mL、加酶量0.07mL/g、水解时间50min时效果最佳,水解液中总还原糖得率可达到52.95%,米氏常数为Km＝80.84mg/mL,Vm＝1.26mg/(mL ·min)。     

响应面法优化山药鱼肉饼的生物抑菌保鲜剂配方

研究了生物保鲜剂对山药鱼肉饼的抑菌效果。在单因素试验的基础上,采用响应面法分析了壳聚糖、乳酸钠、乳酸链球菌素对山药鱼肉饼抑菌保鲜作用的影响,建立了二次回归方程,得到复合生物抑菌保鲜剂的最优配方为:壳聚糖0.35%、乳酸钠4.0%、乳酸链球菌素250 mg/kg,添加此配方保鲜剂的山药鱼饼冷藏10 d测得细菌生长对数值为2.56。     

紫薯在肉制品中的应用前景

自紫薯引入中国,其产品开发类型主要围绕着色素提取和功能性食品进行的;其中功能性食品包括紫薯全粉、冻干食品、紫薯饮料、茎尖蔬菜和休闲食品。结合紫薯的营养价值和紫薯淀粉的理化性质,本文对紫薯在肉制品行业的应用前景进行了探讨,同时为新品研发提供可行性依据。     

紫甘薯保健醋发酵工艺优化

以紫甘薯为原料,液态发酵酿造紫甘薯保健醋,采用单因素试验、正交试验和响应面法优化酿造工艺条件。结果表明:酒精发酵最佳条件为发酵温度30℃、初始糖度16%、发酵时间72h得到酒精度最高;醋酸发酵的最佳条件为发酵温度32.01℃、初始酒精度7.25%、醋酸菌接种量9.79%、初始pH值4.54,紫甘薯醋酸度值最高,预测值为6.69%,与实际值6.73%相符。     

5种多酚类化合物提高紫甘蓝花色苷热稳定性及辅色机理初探

该研究选取儿茶素、没食子酸、香兰素、槲皮素、山奈酚五种多酚化合物作为辅色剂对紫甘蓝花色苷进行辅色,结果表明随着浓度增加,儿茶素和没食子酸的辅色作用不断加强,当浓度达到0.01 mol/L时,辅色作用增长缓慢;香兰素浓度达到0.004 mol/L时,辅色作用最强,浓度继续增加辅色作用反而减弱;槲皮素和山奈酚对紫甘蓝花色苷...     

食品成分对山药淀粉老化度和冻融稳定性的影响

研究了氯化钠、蔗糖、单甘酯对山药淀粉老化度和冻融稳定性的影响,结果表明山药淀粉的老化度随氯化钠浓度的增大而有所增大,随蔗糖浓度、单甘酯浓度的增大而有所减小;山药淀粉的冻融稳定性随氯化钠浓度、蔗糖浓度、单甘酯浓度的增大而改善,氯化钠、蔗糖、单甘酯对山药淀粉的冻融稳定性有促进作用。     

紫甘薯肉丸的研制

以提取色素后的紫甘薯淀粉为原料,研究紫甘薯肉丸的最佳配方,选取紫甘薯淀粉添加量、大豆分离蛋白添加量、卡拉胶添加量3个影响因素进行正交试验。结果表明:2号肉30%、2:8碎肉25%、肥碎15%、食盐1.3%、味精0.3%、鸡蛋6%、鲜姜4%、鲜葱5%、磷酸盐0.4%、料酒0.5%、白胡椒0.1%、紫甘薯淀粉10%、大豆分离蛋白3%、卡拉胶0.4%为最佳配方。所制得的紫甘薯肉丸色泽漂亮,弹性和组织状态良好,口感细腻,咀嚼感强。     

The bone‐protective effect of a Taiwanese yam (Dioscorea alata L. cv. Tainung No. 2) in ovariectomised female BALB/C mice

BACKGROUND: Yam products have been marketed for treating postmenopausal syndromes. This study investigated the effects of Dioscorea alata L. cv. Tainung No. 2 (TNG yam) on the bone density of ovariectomised (OVX) female BALB/c mice and the mechanism whereby TNG yam exerted this effect. Sham and OVX control groups were fed a control diet while remaining OVX mice were randomly allocated into experimental diets, i.e. yam (630 g TNG powder kg^?1), E2 (20 mg 17β‐oestradiol kg^?1), or genistein (2 g genistein kg^?1) diet. After 12 weeks of feeding, the uterine weight, indices of bone mass and caecal short chain fatty acids were determined. RESULTS: Neither a yam nor genistein diet restored the OVX‐induced uterine atrophy as did the E2 diet. The femoral and lumbar bone mineral density (BMD) of mice fed the yam diet was greater than those of the sham group, respectively (P < 0.05 vs OVX control), while the lumbar BMD of yam and sham groups were similar (P > 0.05 vs sham). The femoral ash and calcium content in the yam group was significantly greater than that in the OVX control group, respectively (P < 0.05 vs OVX control). The total short chain fatty acid content in the caecum, only enhanced in the yam group, was not correlated with the calcium content of either bone or the plasma calcium level. CONCLUSION: TNG yam prevented loss of BMD and improved bone calcium status without stimulating uterine hypertrophy in OVX BALB/c mice. TNG yam may be beneficial for postmenopausal women for preventing bone loss. Copyright © 2008 Society of Chemical Industry     

紫薯酸奶发酵工艺优化研究

以牛乳和紫薯为原料制备紫薯酸奶.通过菌种驯化,原料配比和发酵条件优化等试验,确定最佳工艺条件:紫薯浆比例1:4,紫薯奶配比4:6,蔗糖添加量7%,接种量6%,发酵温度44 ℃,发酵时间5.5 h.产品具有紫薯特有的风味.     

超声波辅助提取紫薯花青素及抗氧化性研究

为研究超声波法辅助提取紫薯花青素的工艺条件,考察了提取液浓度、水浴温度、提取时间和料液比4个因素对紫薯中花青素提取率影响,优化了紫薯中花青素的提取工艺。结果表明,紫薯花青素最佳提取工艺是:功率为300W超声波辅助提取时间60min、水浴温度40℃、料液比1∶25、乙酸体积分数15%。在最佳组合条件下,紫薯中花青素提取得率最大。同时,对花青素进行了清除羟基自由基的抗氧化性能力研究。结果表明,pH为7.0时,花青素具备较好的清除羟基自由基能力,紫薯花青素抗氧化能力强于抗坏血酸。