苹果低温高压膨化影响因素研究

以国光苹果为原料,探讨了苹果片厚度、预干燥后水分含量、膨化温度、抽空温度、抽空时间、压力差对苹果脆片产品水分含量、硬度、比容和色泽的影响。结果显示,膨化温度、抽空温度和抽空时间对苹果脆片产品水分含量影响极显著(P<0.01);除膨化温度外,其他因素对苹果脆片产品硬度影响极显著(P<0.01);苹果片厚度、抽空温度、抽空时间、压力差对苹果脆片产品比容影响极显著(P<0.01);除压力差外,其他因素对苹果脆片产品色泽影响极显著(P<0.01)。膨化苹果脆片的最佳工艺为:苹果片厚度5mm,水分含量30%,膨化温度100℃,抽空温度80℃,抽空时间0.5h,压力差0.3MPa。     

轻度冻结和真空渗渍处理对微波膨化芋艿脆片质构的影响

研究了浸渍液配方(A)、真空渗渍方式(B)和冻结时间(C)等预处理对微波膨化芋艿脆片质构的影响。结果表明:影响芋艿脆片胶黏性、咀嚼性和感官评分的重要因子为A,影响芋艿脆片硬度和表观密度的重要因子分别为B和C;真空渗渍方式和冻结时间对芋艿脆片的表观密度均有显著的影响(P0.05),B3处理的芋艿脆片表观密度显著小于B1和B2,C2处理的芋艿脆片表观密度显著小于C1和C3。感官评分与芋艿脆片凝聚性、胶黏性和咀嚼性质构参数之间存在极显著的多元回归相关性,且咀嚼性构成了脆片感官评分的决策因子,胶黏性成为脆片感官评分波动的限制因子;最佳预处理工艺组合为A3B3C2,即经—18℃冻结24 h,2%食盐+10%糖真空渗渍1.5min+1.5 min,微波膨化可制得硬度(4.8 N)、凝聚性(0.20)、胶黏性(0.93 N)和咀嚼性(0.03 N·mm)均较低,感官评分最高(9.0分)的芋艿脆片。     

预处理对微波膨化苹果脆片质量的影响

通过研究物料厚度、水分含量、预干燥温度、均湿时间等预处理操作对微波膨化苹果脆片的膨化效果及品质影响，得出较佳的工艺参数。试验表明，在苹果片厚度为5mm、苹果片初始水分含量18％，预干燥温度85℃，均湿时间3d，微波功率为中档火，微波时间30s时，所得苹果脆片膨化效果及品质较好。     

油炸洋葱脆片的研制

以洋葱粉和马铃薯淀粉为主要原料,从原料的配比和成型条件等方面对洋葱脆片的制作工艺进行了研究.确定了洋葱脆片的制作工艺、主要工艺条件和配方.并对产品的含水量、酥脆度、色泽和外形的平整性等品质特性进行了评价.洋葱脆片的最佳配方为;洋葱粉35g.马铃薯淀粉34g,糯米粉12g,增稠剂0.49g;最佳工艺条件为;洋葱脆片的切片厚度为2mm,油炸温度为140℃,油炸时间为10s,产品具有香、酥、脆的特点.     

微波膨化加工芒果脆片的研究

通过对预干燥后的芒果条、芒果片进行微波膨化,研究水分含量、物料形状、糊精、CaCl2对微渡膨化的影响,并对产品膨化率、酥脆度、色泽、外形平整性进行评价.结果表明:热风干燥温度以45℃为宜,片状物料比条状物料更适于微波膨化;芒果片微波膨化最适条件为,通过预干燥使膨化前芒果片水分质量分数降低至12%,再微波膨化22 s,得到产品其膨化率、酥脆度、色泽、外型都良好;糊精浓度在7%以下时,对脆片的酥脆性、色泽有一定的改善作用,CaCl2则没有改善芒果片品质的作用.     

微波膨化猕猴桃脆片工艺的优化

以猕猴桃为原料,研究了微波膨化猕猴桃脆片的最佳工艺。通过单因素实验分别考察了水分含量、切片厚度以及微波时间等因素对膨化率的影响。在此基础上,以膨化率为指标,设计了响应面分析方案,通过数学推导及实验分析,得出微波膨化猕猴桃脆片的数学模型及相关参数。结果表明,微波膨化猕猴桃脆片的最佳工艺参数为:猕猴桃片的水分含量为20%、切片厚度4mm、微波时间62s,在此优化条件下得到的猕猴桃脆片膨化率为73.8%,与回归方程的预测值(73.1%)基本一致。膨化后猕猴桃脆片的水分含量为5.4%,因此会有较酥脆的口感和贮藏稳定性。VC含量在猕猴桃片干燥的过程中和膨化后都显著的减少了。     

黑米、薏米、荞麦混合挤压膨化工艺及机理的研究

以优质的黑米、薏米、荞麦粉为原料,采用先进的现代挤压膨化技术,研制集营养、保健、食用为一体的五谷杂粮膨化粉及主食品。通过双螺杆挤压机、单螺杆挤压机对物料进行对比膨化实验,确定相应的混合物料挤压膨化工艺流程及参数。结果表明,双螺杆挤压比单螺杆挤压膨化效果理想,3种物料混合后膨化效果好,各原料比例为:m(黑米)∶m(薏米)∶m(荞麦粉)=45∶15∶40。对混合物料膨化的操作参数为:物料水分15%～20%,挤压温度171～184℃,螺杆转速90～114r/min,膨化物的糊化度可达83.3%～86.4%。本文还讨论了混合物挤压膨化的物理化学变化和机理。     

双螺杆挤压机操作参数对蚕豆挤出物径向膨化率的影响

以蚕豆粉为原料,以德国布拉本德DSE-25型双螺杆挤压实验室工作站为设备,研究挤压温度和物料含水率对挤出物径向膨化率的影响规律,进一步明确挤压温度、物料合水率与单位机械能耗和径向膨化率之间的关系.试验结果表明:挤压温度、物料含水率对单位机械能耗(SME)有极显著影响(α＜0.01);挤压温度、物料含水率和喂料速度对挤压物径向膨化率有极显著影响(α＜0.01),螺杆转速对挤压物径向膨化率有显著影响(α＜0.05).SME和径向膨化率两者之间呈显著正相关,相关系数为0.985 7(P ＜0.05).     

常压油炸马铃薯脆片加工工艺参数的研究

以适于油炸加工的马铃薯品种--大西洋为原料,研究了切片厚度、坯料烘干时间(含水量)、被膜剂浓度、油炸时间、油炸温度对常压油炸马铃薯脆片品质的影响,确定了常压油炸马铃薯脆片的加工工艺参数,即马铃薯切片厚度为2.0mm,油炸坯料于50℃温度下烘80min,含水量控制在60%左右,油炸前用0.8%的CMC-Na溶液被膜,在180℃油温下炸制2min。     

响应面法优化低温真空油炸鱼糜脆片加工工艺

本研究以油炸温度、油炸时间和鱼糜脆片厚度为主要影响因素,对真空油炸工艺条件进行单因素条件探索。采用Box-Benhnken响应面法,以产品脂肪含量(R₁)、色差(R₂)和断裂力值(R₃)为响应值进行实验条件优化。结果表明:最优的油炸鱼糜脆片工艺参数:油炸温度为105 ℃,油炸时间为3 min,鱼糜脆片厚度为2.00 mm。在此条件下,实验R₁值为23.13%,R₂值为14.20,R₃值为14.53 N,与模型预测值拟合度很好。结论:响应面法对低温真空油炸鱼糜脆片工艺条件优化合理可行,为实现鱼糜脆片的工业化生产提供了理论依据。     

Production and characterization of Xanthosoma sagittifolium and Colocasia esculenta flours

ABSTRACT:  The physical proximate composition and physicochemical characteristics, microbiological stability, and in vitro alpha-amylolysis rate of flours produced by conventional dehydration techniques of the edible portions of the aroids Xanthosoma sagittifolium and Colocasia esculenta were investigated. Flours from the edible portion of both tubers did not show significant statistical differences in moisture, Aw, crude protein, total sugars, amylose, and amylopectin contents. C . esculenta flour showed higher crude fat, total, soluble, and insoluble dietary fiber, and mineral (P, Ca, Fe, and Zn) contents, whereas X. sagittifolium flour showed higher starch, ash, and reducing sugar content than its counterpart. With regard to physical and physicochemical characteristics, X . sagittifolium flour showed higher titratable acidity and relative density values, being darker and more yellowish than its counterpart. On the other hand, X . sagittifolium flour showed higher gelatinization temperature than C . esculenta flour. Parameters such as viscosity during the holding time (95 °C for 30 min), viscosity at 50 °C, setback, and consistency were lower in C . esculenta flour than X . sagittifolium flour. The viscosity peak and breakdown indexes were higher in C . esculenta flour than in the X . sagittifolium sample. The colony forming units (CFU) of the microorganisms were much lower than those reported in the literature for similar products. Moreover, due to their moisture content and water activity, these flours could be classified as dry foods and they are shelf-stable foods. The results reflect that flours with good chemical, physicochemical, and nutritional quality and satisfactory microbiological stability may be produced from these aroids.     

香芋味杂粮酥性饼干的配方优化

以江永香芋为特征风味原料,将其添加至杂粮酥性饼干的配方中。以综合感官评分为指标,采用模糊数学感官评价法结合单因素-正交试验确定了香芋粉、低筋面粉、白砂糖和植物油的最适添加量。结果显示,酥性饼干的最适配方为低筋面粉36.47%、香芋粉15.20%、植物油13.68%、白糖12.16%、鸡蛋6.08%、小苏打0.06%、泡打粉0.06%,燕麦片3.04%,小米粉6.62%,牛奶6.63%。在烘烤温度190 ℃、烘烤时间为14 min的参数下,综合感官评分为90.16。同时,该产品的卫生指标符合GB 7100-2015《食品安全国家标准饼干》中的质量要求。     

香芋淀粉糊的特性

研究了糊浓度、温度、回转速度、pH和盐等因素对香芋淀粉糊粘度的影响 ,测定了香芋淀粉糊的透光率、冻融性、凝沉性和抗霉菌能力等性质。结果表明 ,香芋淀粉糊具有透明度低 ,冻融稳定性差 ,沉降性好等性质。在酸性条件下 ,淀粉糊粘度迅速下降 ;在中性条件下 ,糊粘度最高。不同的盐对淀粉糊的影响不同 ,其中硼砂和一些过渡金属盐的存在使糊粘度升高。     

Effect of Extrusion Variables on Cassava Extrudates

Cassava flour was extruded by varying parameters of feed moisture; temperature; screw speed and feed rate. We investigated significance of each variable and interactions between variables on each extrudate characteristic. Optimum expansion (2.82) was at 11% feed moisture 120–125 °C; screw speed, 520rpm; feed rate, 250g/min. Effect of feed moisture was most significant on expansion, bulk density and extrudate moisture. Increasing temperature, increased expansion and water solubility, but decreased bulk density, extrudate moisture and water absorption. Screw speed most influenced water absorption and solubility. Extrudate moisture correlated negatively (P<0.01) with extrudate expansion. Water solubility index of extrudate negatively correlated (P<0.05) with extrudate moisture and water absorption index but correlated positively (p<0.05) with expansion.     

Thiamin, Riboflavin, and Nicotinic Acid Contents of Tropical Root Crops from the South Pacific

The thiamin, riboflavin, and nicotinic acid contents of sweet potato (Ipomea batatas, taro (Colocasia esculenta), giant taro (Alocasia macrorrhiza), giant swamp taro (Cyrtosperma chamissonis), taro (Xan-thosoma spp), yam (Dioscorea alata and D. esculenta) were determined for fresh and 40°C dried material obtained from six South Pacific countries. Losses on drying at 40°C for 2-3 days were 10-15% for the three vitamins. Sweet potato contained the largest amount of thiamin (40-120 μg/100g fresh weight) and along with Colocasia esculenta and Xanthosoma spp. the largest amounts of nicotinic acid. The root crops provided inadequate amounts of thiamin, riboflavin, and nicotinic acid with values ranging from 12-123, 12-59 and 220-1310 Hg/100g fresh weight, respectively. Losses on cooking were about the same for all vitamins and root crops, with about a 20% loss on boiling (water retained) or baking and about a 40% loss on boiling (water discarded).     

香芋淀粉磷酸酯的糊化特性研究

研究了香芋淀粉磷酸酯的糊黏度、透明度、冻融稳定性、沉降稳定性、糊化难易程度、耐糖、耐盐和抗霉菌能力。结果表明,与原淀粉相比,香芋淀粉磷酸酯更容易糊化,透明度高,沉降稳定性好,冻融稳定性和抗霉菌能力有所改善,糊黏度减小。随着取代度的增加,香芋淀粉磷酸酯的糊化变得容易,耐盐和耐糖能力提高;透明度先增后减;糊黏度则先减后增。取代度的变化对沉降性和抗霉菌能力影响不大。     

可口革囊星虫体腔液多糖碱提工艺优化及其抗氧化性研究

为提高可口革囊星虫体腔液利用率,探究可口革囊星虫体腔液多糖的最佳提取工艺及其体外抗氧化特性。采用碱浸提法提取可口革囊星虫体腔液多糖,正交试验法优化多糖提取工艺。以总还原力、1, 1-二苯基-2-三硝基苯肼（DPPH）清除率和羟基自由基清除率为指标测定其抗氧化性,并利用高效液相色谱测定单糖组成,红外光谱对多糖成分进行初步分析。结果表明可口革囊星虫体腔液多糖提取最佳工艺条件为提取温度50 ℃、碱提时间3 h、NaOH质量浓度1.5%,在此工艺下多糖得率为0.92%。该多糖的总还原力、DPPH清除率和羟基自由基清除率的半数清除浓度（IC₅₀）分别为2.976、0.567和0.605 mg/mL。高效液相色谱显示该多糖主要由葡萄糖组成。红外光谱结果显示该多糖是一种含有乙酰氨基和吡喃环,以α-糖苷键连接的多糖。由此可知,可口革囊星虫体腔液多糖有较好抗氧化性,具有良好的应用前景。     

香芋皮多酚的超声提取工艺优化及其抗氧化活性

为了对香芋进行高效利用,以香芋加工副产物香芋皮为原料,采用超声波辅助提取香芋皮多酚,在单因素试验基础上结合正交试验方法对香芋皮多酚提取条件进行优化,并初步评价其体外抗氧化活性。结果表明,香芋皮多酚最佳的提取工艺为:超声功率400 W,乙醇浓度45%,料液比1:55 g/mL,超声时间35 min,此条件下香芋皮中多酚得率达到(23.61±0.36)mg/g。抗氧化活性实验表明,在最佳条件下提取得到的香芋皮多酚具有一定的还原能力,20.0 μg/mL的香芋皮多酚还原能力为0.4431±0.0027,并且其对DPPH自由基和ABTS自由基清除作用均表现出良好的清除效果,相应的IC₅₀值分别为(5.6647±0.2545)和(36.3630±2.4013)μg/mL,说明香芋皮多酚具有较强的抗氧化活性。     

Effect of frying variables on French fry properties

This work focuses on the effect of frying variables (repeated frying, potato‐to‐oil ratio, potato distribution in the fryer, oil type and potato variety) on French fry properties (water content, oil content, crust thickness and shrinkage). Furthermore, the rate of change in French fry properties during a frying batch is investigated. The temperature was acquired in several positions within the oil and the potato. It was found that when repeated frying was conducted up to regulation limits for frying oil use, the examined French fry properties were not significantly affected. On the contrary, the potato‐to‐oil ratio, potato distribution and potato variety significantly affected the water content of French fries. The most significant changes occurred during the first 1–2 min of a frying batch. According to the temperature measurements, the crust‐core front continued to advance after this first frying period. However, there was no observable crust thickness increase; this was attributed to crust shrinkage.