以葛根粉酶解物为壁材的粉末油脂理化性质及稳定性研究

对以葛根粉酶解物为壁材的粉末油脂进行了感官评价和理化性质测定.结果表明:产品粉体洁白,有葛根粉的清香,颗粒细,流动性较好；产品水分为2.72％,包埋率达89.42％,溶解度为95.60％；复水乳液平均粒径为239.3 nm.扫描电镜结果显示,产品颗粒为表面光滑、内部空心的完整球形,其囊壁致密且有一定厚度,无裂纹和孔隙.差示扫描量热及热重分析结果表明,产品热熔解温度高,常温下处于稳定的玻璃态,具有良好的热稳定性.Schaal加速氧化试验结果表明,产品的氧化稳定性较好,在室温下的货架寿命可达16个月.     

脱脂乳的不同热处理工艺对酸奶质构和微观结构的影响

为研究双孢蘑菇粉对酸奶理化性质的影响,以酸奶为原料,探究将不同质量分数（0.0%、1.5%、3.0%、4.5%、6.0%和7.5%）的双孢蘑菇粉（Agaricus bisporus powder,ABP）添加到酸奶中,并对在不同ABP添加量下的酸奶流变学和质构特性进行研究。结果表明：当ABP添加量为1.5%时,酸奶的动态黏弹性、表观黏度、稠度、硬度和内聚性对比对照组均有所降低;而当ABP添加量高于1.5%时,酸奶的动态黏弹性、表观黏度、稠度、硬度和内聚性会随ABP添加量的增加而增大;扫描电镜结果表明,ABP添加量为0.0%和1.5%的酸奶表现为具有较多空隙的酪蛋白纤维状网络结构,并且随着ABP添加量的增加,纤维网络中的空隙逐渐被ABP颗粒所填充,形成致密连续的空间结构,使酸奶的硬度、粘稠度和稳定性得到增强。综合分析可知,当ABP的添加量为1.5%~3.0%时,可使酸奶具有较好的流变性和质构特性。本研究结果为双孢蘑菇风味乳制品的研究和开发提供了理论和数据支持。

     

苦杏仁多酚氧化酶的分离纯化及部分特性分析

以苦杏仁为原料,采用(NH4)2SO4分级沉淀法对苦杏仁多酚氧化酶进行初步分离后经Sephadex G-75凝胶柱层析进一步纯化,冷冻干燥后即得苦杏仁多酚氧化酶纯品;通过凝胶电泳和热分析试验测定多酚氧化酶的相对分子质量和变性温度。结果表明:经分离纯化后苦杏仁多酚氧化酶的纯化倍数为49.03倍,该酶可能存在同工酶且相对分子质量分别约为21.9 k D和23.2 k D;苦杏仁多酚氧化酶变性温度为60.03℃。为苦杏仁加工过程中的酶促褐变控制提供部分理论参数。     

Physicochemical properties of steamed bread fortified with ground linseed (Linum usitatissimum)

Chinese steamed bread (CSB) is a staple food among Asian populations. Linseed (Linum usitatissimum) is an emerging ‘healthy’ food ingredient rich in a range of bioactive components. Ground linseeds were incorporated in northern style CSB formulation up to 20%. Various physico-chemical, nutritional and sensory properties of the resulting CSB were studied. Linseed addition decreased the specific volume and spread ratio of CSB, while increasing the hardness and chewiness in a dose-dependent manner. Linseed addition up to 15% little affected the overall sensory acceptability of CSB. Nutritionally, linseed addition increased the in vitro antioxidant activities of CSB, while decreasing in vitro starch digestibility and expected glycaemic index. It may be concluded that linseed has the potential to enhance the nutritional quality of CSB without negatively affecting the eating quality.     

Biochemical studies of some non-conventional sources of proteins Part 6. Physicochemical properties of apricot kernel proteins and their changes during detoxification

The physico-chemical properties of apricot kernel proteins before and after detoxification treatments with water and ammonium hydroxide were determined. Water treatment shifted the λ_max to 278 nm while ammonium hydroxide has no effect. Fluorescence spectrum showed emission red shift and quenching for both detoxification treatments. Sedimentation velocity pattern of the untreated proteins contained two peaks having S_20,w values of 6.8S and 11.1S. Detoxified kernels showed aggregates of 15.4S and 16.9S due to water and ammonium hydroxide treatment, respectively. Gel filtration pattern consisted of three peaks for all samples, meanwhile ion-exchange chromatography showed an additional peak. HPLC, SDS-PAGE and isoelectric focusing-PAGE proved dissociation of the high molecular weight proteins as well as removal of the low molecular weight protein fractions due to detoxification treatments.     

Physicochemical properties and storage stability of spray‐dried soya bean sprout extract

Amylase is a very important enzyme due to its wide food applications. To preserve amylase activity in soya bean sprout extract (SSE), SSEs were spray‐dried with 10% maltodextrin and 0–3% alginic acids, and their physicochemical properties and storage stability were compared with freeze‐dried one. SSE exhibited maximum amylase activity at pH 7.0 and 60 °C, with the most active substrate specificity towards soluble starch. Spray‐dried SSEs exhibited higher water solubility index (WSI) and in vitro relative amylase activity but lower water vapour sorption (WVS) and smaller particle size than freeze‐dried SSE. For spray‐dried SSEs, particle size, WSI and in vitro relative amylase activity increased while WVS decreased with increasing % alginic acid. This study demonstrated that spray drying of SSE, especially with 10% maltodextrin and 2% alginic acid, was effective in keeping amylase active and stable during 7‐week storage at room temperature (25 °C).     

In vitro digestibility,physico-chemical and functional properties of apricot kernel proteins

The chemical composition of apricot kernel flour and protein isolates was determined. The flour contained about 48% protein, mainly albumins. The solubility at different pH values showed a single isoelectric point at pH 4 and the solubility increased in both acidic and alkaline pH. The digestibility of the protein was high in the pepsin-pancreatin system and quite low when pepsin or trypsin was used.The ultraviolet absorption spectrum of the proteins of both flour and protein isolates was typical of those of other vegetable proteins. The polyacrylamide gel electrophoresis pattern of apricot kernel proteins consisted of four major protein fractions. Water and fat absorption and emulsification capacity of flour and protein isolates were quite comparable with that of soybean. Detoxified apricot kernel flour and protein isolates appear to be good sources of protein for food products.     

杏仁皮油理化指标和脂肪酸组成分析

为了开发利用杏仁皮资源,对杏仁皮油的主要理化指标进行了测定,并采用气相色谱法分析了杏仁皮油的脂肪酸组成。结果表明:杏仁皮油不饱和脂肪酸含量高达90%,其中油酸含量为34.20%,亚油酸含量为51.77%,杏仁皮油的酸价为10.220mg KOH/g,过氧化值为0.0731g/100g,碘值为130.1 g/100g,是一种优质的植物油。     

Physicochemical and antioxidant properties of extruded cornmeal with natural cocoa powder

Songpyeon is a Korean traditional food made of rice with different fillings. The fillings may affect the qualities of songpyeon, such as shelf-life. Therefore, quality characteristics of songpyeon filled with chopped black eyed peas (CBP) and unchopped black eyed peas (UCBP) were investigated during storage at room temperature. As a result, all samples had moisture content and pH values favorable for microbial growth. Hardness, gumminess, and chewiness were increased during storage. All sensory parameters values decreased steadily in stored songpyeon. The shelf-life of songpyeon was suggested to be only 2 days by the panelists. UCBP had higher number of total microbial loads, yeasts, and molds than those of CBP. Coliforms were not detected in songpyeon during storage. These results suggested that songpyeon filled with UCBP had a shorter shelf-life than songpyeon filled with CBP.     

酸枣仁油的理化性质及成分分析

对酸枣仁油的理化性质和脂肪酸组成进行了分析。结果表明,酸枣仁油主要由6种脂肪酸构成,其中油酸、亚油酸含量最高,分别为49.1%、26.0%;通过测定酸枣仁油Sn-2位脂肪酸组成,确定了酸枣仁油甘三酯的脂肪酸分布。酸枣仁油VE总含量为18.67 mg/100 g油。使用GC/MS对酸枣仁油的不皂化物成分进行了分析,检测出7种主要物质,其中角鲨烯的含量高达39.2%(占酸枣仁油不皂化物总量)。     

Evaluation of sorption properties of Turkish tarhana powder

Moisture adsorption isotherms of commercial tarhana powder, a popular Turkish food used in soup making, were determined at 10 °C, 20 °C and 30 °C. Gravimetric static method was applied at 0.08–0.92 water activity range. The data was fitted to Guggenheim-Anderson-deBoer(GAB), Oswin, Hendersonand Brunauer-Emmett-Teller(BET)equations. Mean relative deviation (%E) was used to compare the goodness of fit. The BET was found the best equation for the range of water activity 0.08–0.58. The GAB equation was found adequate and gave similar result with the Oswinequation at 10 °C and 20 °C, while the Oswinequation was better for characterizing the adsorption behavior of tarhana sample for the whole range of temperature and water activity studied.     

苦杏仁皮中生物活性成分的研究进展

苦杏仁皮是苦杏仁重要的加工副产物,其富含多种对人体有益的生物活性物质,目前食品工业针对苦杏仁皮的回收利用尚无有效的解决方案,因此造成了苦杏仁皮资源的极大浪费。该文介绍了当前苦杏仁去皮方法及存在的问题,并综述了苦杏仁皮中生物活性成分(多酚类化合物、黑色素、苦杏仁苷、膳食纤维)的研究进展,为苦杏仁皮资源的深入研究、精深加工、综合利用以及具有高附加值的苦杏仁皮产品的开发奠定理论基础。     

干燥方法对杏肉全粉品质及抗氧化活性的影响

采用微波干燥(MD)、热风干燥(HAD)、微波真空干燥(MVD)、微波对流干燥(MCD)4种干燥方法制备纯天然杏肉全粉,比较了干燥方法对杏肉全粉营养成分、物理特性、感官品质和抗氧化能力的影响。结果表明,干燥方法对杏肉全粉品质的影响显著(P0.05),MVD和MCD 2种方法干燥的杏肉全粉总糖和还原糖保留较好,并且MCD法干燥的产品总酚和VC损失最少,而HAD法对总酸的保留最好;MD法制备的产品吸湿性和结块度最低,MCD法制备的产品堆积密度和休止角最小,且获得的感官评价分值最高(95.2分);制备的杏肉全粉还原力及清除DPPH、超氧阴离子和羟自由基的能力呈显著的量效依赖性且存在显著差异,MVD法制备的产品对DPPH自由基清除能力最强,而MCD对羟自由基、超氧阴离子自由基的清除能力最强,还原力也最大,分别为88.5%,85.1%,1.98。     

花椒籽壳蛋白与籽仁蛋白理化性质分析

以花椒籽为原料,主要研究花椒籽仁与籽壳脱脂后的基本化学成分、蛋白等电点、氨基酸组成、亚基组成以及蛋白组分等理化性质的差异。结果显示,脱脂后的花椒籽仁和籽壳中蛋白质含量分别为61. 17%、8. 54%,其蛋白等电点分别为3. 5、4. 5。花椒籽仁脱脂粉的氨基酸总量为43g/100 g,必需氨基酸占总量的27. 31%,籽壳脱脂粉的氨基酸总量为4. 07 g/100 g,必需氨基酸占总量的26. 78%,两者主要的氨基酸为天冬氨酸、谷氨酸和精氨酸。采用Osborne法对蛋白分类,花椒籽仁中清蛋白、球蛋白、谷蛋白、醇溶蛋白的含量分别为7. 76%、72. 06%、15. 80%、1. 22%,籽壳中相对应的蛋白含量分别为13. 12%、56. 54%、21. 45%、3. 25%。SDS-PAGE电泳分析表明:花椒籽仁粗蛋白有7个条带,相对分子质量在0～66. 200 k Da之间,籽壳粗蛋白有2个条带,相对分子质量在18. 400～35. 000 k Da之间;花椒籽仁4种蛋白组分相对分子质量较小,亚基相对分子质量分布在0～45 k Da之间,花椒籽壳4种蛋白组分分布范围较小,亚基相对分子质量分布在14. 4～35 k Da之间。     

甜杏仁油的提取研究与应用

甜杏仁中含有50％～60％的油脂,为了合理利用甜杏仁资源,研究了提取甜杏仁油最佳方法及最优条件。结果表明,提取甜杏仁油的最佳条件为：以石油醚为提取溶剂,在70℃下以料溶比1：15提取2h。在此条件下甜杏仁油提取率为56．3％。     

苦杏仁脱苦方法研究进展

本文主要综述了杏仁、苦杏仁苷及苦杏仁脱苦的传统和现代方法,并对每种脱苦技术方法的优缺点进行了比较,同时也对极有可能用于产业化中的微波和超声波脱苦方法的发展趋势进行了展望。      

Physicochemical and functional properties of full fat and defatted cashew kernel flours

Full fat and defatted cashew kernel flours were prepared and analysed for their physicochemical and functional properties. There were significant increase in protein and carbohydrate contents of the flour as a result of defatting. The defatted flour possessed higher Ca, P, Na and K contents. It had improved gel strength, foaming and emulsion properties. Foam capacity for the full fat and defatted flours increased from 42% to 50% and 55% to 57% with increased NaCl concentration up to 0.25 and 0.05  m , respectively. The foam capacity and stability of the flours were also pH dependent. The emulsion activity and stability of both flours decreased with increasing NaCl concentration. Minimum and maximum protein solubility were at pH 4 and 8, respectively for the full fat and defatted flours. These results suggest that defatted cashew flour may have potential application as a functional ingredient and as a supplement in foods.     

Physicochemical and sensory properties of milk fortified with iron microcapsules prepared with water‐in‐oil‐in‐water emulsion during storage

This study investigated the possibility of fortifying iron microcapsule powder into milk and the effects of the fortification on the physicochemical and sensory properties of the products during storage. The iron microcapsules were prepared by the water‐in‐oil‐in‐water (W/O/W) emulsion technique. Fortifying the lower concentrations (0.1–0.3%, w/v) of iron microcapsules into the milk samples did not significantly change thiobarbituric acid values. The L‐values for the milk samples were not significantly influenced by fortifying iron microcapsules (0.1–0.7%, w/v). The overall acceptability scores were not affected when the lowest concentration of iron microcapsules (0.1%, w/v) was fortified into the milk.