真空油炸香菇脆片工艺优化

油炸温度、真空度和油炸时间是真空油炸过程中的重要参数,该文对香菇脆片真空油炸工艺进行优化,得到最佳工艺参数为油炸温度80℃、真空度0.089 MPa、油炸时间36.65 min,获得的香菇脆片含油率为22.53%,破碎力为650.31 g。香菇脆片品质分析表明,真空油炸较好保持了香菇脆片的多糖含量,具有较高的复水比。     

低温真空油炸柿子脆片工艺优化及其品质分析

本文以柿子为原料，开展油炸温度、油炸时间、脱油时间以及切片厚度4个单因素对低温真空油炸柿子品质影响，并根据Box-Behnken试验原理，以柿子脆片的脆度、色差为响应值对低温真空油炸柿子脆片加工工艺进行优化，进一步对最终产品理化成分、微生物指标和微观结构进行分析。结果表明，油炸温度、油炸时间、脱油时间和切片厚度都影响柿子脆片的脆度和色差，经响应面优化试验分析并根据实际修正确定低温真空油炸柿子脆片的最佳工艺为：脱油时间5 min、油炸时间50 min、油炸温度80℃、切片厚度5.5 mm。该条件下柿子脆片脆度858.97 g、色差值ΔE 17.28、水分含量2.60%、含油率为22.53%、可滴定酸0.34 g/L、VC含量31.20 mg/100 g；柿子脆片产品色泽金黄、形状完整，脆片内部呈现蜂窝状多孔疏松结构，产品口感酥脆，微生物指标符合卫生要求。本研究可为柿子低温真空油炸脆片产品的开发提供技术支撑。     

低温真空油炸红椒片的生产工艺研究

为提升淮安红椒的附加值,以淮安红椒为研究对象,采用低温真空油浴方法,开发一款即食的红椒脆片休闲食品。通过研究辣椒片的宽度、调味液中白糖的质量分数、超声波浸渍时间和真空油炸时间4个因素对淮安红椒脆片的含油率、含水率和感官评分的影响,确定其较佳的生产工艺范围。再通过正交试验确定淮安红椒脆片的最佳工艺:辣椒片宽度为3 cm、白糖质量分数为15%、超声波浸渍时间15 min、真空油炸时间20 min。由此工艺加工制得的淮安红椒脆片含油率低,具有外形完整、色泽美观、口感酥脆等良好的感官品质。     

香菇脆片真空油炸—真空微波联合干燥工艺优化

采用真空油炸—真空微波联合干燥技术对香菇脆片进行了干燥,并对其工艺条件进行了优化。结果表明,香菇脆片真空油炸—真空微波联合干燥最佳工艺条件为油炸温度80 ℃、真空度0.095 MPa、油炸时间18.6 min;微波真空度0.095 MPa、微波功率密度2.0 W/g,脱水至含水率5%。此条件下香菇脆片的含油率为15.18%,破碎力为710.35 g,与预测值(15.09%和704.91 g)较接近。与真空油炸香菇脆片相比,联合干燥产品破碎力提高了5.93%,但含油率降低了29.79%,感官评分增加了11.38%。     

香菇脆片真空油炸-热风联合干燥工艺研究

传统真空油炸果蔬脆片含油率偏高,品质有待改善.对真空油炸香菇脆片加工的干燥工艺进行了研究,以热风风速、分阶段干燥的水分转换点、热风干燥阶段温度和真空油炸温度为影响因素,进行了正交优化试验.以含油率结合产品感官为评价指标,得出香菇脆片真空油炸-热风联合干燥最佳工艺条件为:风速1.0 m/s、水分转换点35%、热风温度65℃、真空油炸温度90℃.该工艺加工的香菇比传统真空油炸香菇脆片含油率降低1.78%,产品感官品质也有所提高.     

即食杏鲍菇片真空低温脱水工艺研究

为得到产品品质高、含油率低的即食杏鲍菇脆片生产工艺,选取杏鲍菇作为研究对象,研究杏鲍菇真空低温脱水前预处理以及真空油炸温度、时间和脱油时间对菇片含油率及产品品质的影响,并得出即食杏鲍菇片的最优真空低温脱水工艺。结果表明：当1.5mm厚的杏鲍菇片经80℃烫漂90s后,在料液比为1:15(g/mL)的15%麦芽糊精溶液中超声辅助浸渍15min、60℃热风预干燥20min处理后80～90℃真空油炸10min,并旋转脱油10min,其产品具有相对较低的含油率及较好的感官品质。该工艺可制得的产品感官良好、含油率低,可在实际生产中应用。     

响应面法优化真空油炸-热风联合干燥桃脆片工艺

以真空油炸温度、分阶段干燥的水分转换点、后期热风干燥阶段温度为影响因素,以桃脆片含油率为评价指标进行响应面优化分析,得出联合干燥最佳工艺参数为切片厚度2mm、漂烫3min、真空油炸温度87.1℃、水分转换点15.9%、热风干燥温度65.5℃。根据实际操作条件,调整最佳联合干燥工艺为切片厚度2mm、漂烫3min、真空油炸温度87℃、分阶段干燥的水分转换点16%、热风干燥温度66℃。验证实验表明,最佳工艺条件下测得联合干燥桃脆片的含油率为12.5%,与理论预测值的误差为5.9%。     

低温真空油炸哈密瓜脆片工艺研究

本文研究了低温真空油炸制取哈密瓜脆片的工艺,在单因素实验的基础上,通过正交试验来优化工艺参数。经优化后最佳参数为切片厚度3mm,脆片炸前含水量20％。护色温度为75℃,时间为1min;油炸温度为8013,时间为40min,真空度为O．08MPa。     

响应面法优化真空油炸红薯脆片的工艺研究

在真空油炸工艺中研究油炸时间、油炸温度以及真空度对红薯脆片脂肪含量和破碎力的影响,在单因素的试验基础上根据中心组合试验设计原理,分别采用响应曲面分析法对真空油炸红薯脆片工艺进行优化。综合考虑红薯脆片的脂肪含量和破碎力,选择油炸温度100~105℃、油炸时间18min、真空度0.090~0.095MPa作为最佳真空油炸红薯脆片工艺范围。     

真空低温油炸紫香芋脆片预处理工艺优化

研究真空油炸紫香芋脆片的预处理工艺。在单因素试验基础上,对主要影响因素进行正交试验设计,系统研究了切片厚度、漂烫条件、冷冻条件等影响真空低温油炸紫香芋脆片质量的预处理因素,获得了真空低温油炸紫香芋脆片的最佳预处理工艺:切片厚度3 mm;漂烫温度90℃,漂烫时间4 min;在-30℃的冷冻环境中,冷冻18 h较为合适;在-0.094 MPa~-0.098 MPa的真空度条件下,95℃真空油炸15 min。真空油炸紫香芋脆片最大程度地保存了紫香芋的营养价值,经测定花青素含量为1.38 mg/g,脂肪质量分数为15.49%,破碎力为437.3 g。产品带有清晰的纹理,口感酥脆,无渣感,无油腻感。     

DEEP-FAT FRYING OF YAM SLICES: OPTIMIZATION OF PROCESSING CONDITIONS USING RESPONSE SURFACE METHODOLOGY

The deep-fat frying of yam slices was investigated with the aim of optimizing the processing conditions. During frying, frying temperature, initial dry matter and frying time have a significant effect on moisture loss and oil uptake. Response surface methodology central composite rotatable design was used to study the effects of the independent variables on quality attributes of yam chips. Breaking force, oil content, moisture content and color parameters were determined. Statistical analysis with response surface regression showed that breaking force, oil and moisture contents and color parameters ( L* and a* ) were significantly ( P <  0.05) correlated with frying temperature, initial dry matter and frying time. The optimum conditions were a frying temperature of 175–180C, using tubers of initial dry matter of 0.179–0.214 kg/kg with a frying time of 4–5 min. It was suggested that the regression equation can be used to estimate the dependent variables for fried yam chips except b* (yellowness) parameter.

PRACTICAL APPLICATIONS

It is expected that the optimized processing conditions highlighted in this work will be useful in obtaining fried yam chips of acceptable quality attributes. This optimized condition would be a good prospect for commercialization in small-scale industries.     

Effects of processing conditions on the quality of vacuum fried apple chips

The effects of pretreatment and processing conditions on the quality of vacuum fried apple chips were studied. As blanched apple slices were pretreated by immersing in fructose solution and freezing prior to vacuum frying, more uniform porosity was observed on the surface (or cross-section) of apple chips as examined by scanning electron microscopy (SEM). During vacuum frying, the moisture content and breaking force of apple chips decreased with increasing frying temperature and time while the oil content increased. The L values of fried apple chips decreased apparently with increasing frying temperature. However, when apple slices were fried at 100°C for up to 20 min, both a and b values increased rapidly. Statistical analysis with the central composite rotatable design showed that the moisture content, oil content, color, and breaking force of apple chips were significantly (P⩽0.05) correlated with concentration of immersing sugar solution, frying temperature and frying time. Based on surface responses and contour plots, optimum conditions were: vacuum frying temperature of 100–110°C, vacuum frying time of 20–25 min, and immersing fructose concentration of 30–40%.     

Effects of processing conditions on the quality of vacuum‐fried carrot chips

The effects of pretreatment and vacuum frying conditions on the quality of fried carrot chips were studied. The moisture and oil contents of fried carrot chips were significantly (p < 0.05) reduced when blanched carrot slices were pretreated by immersion in fructose solution and freezing prior to vacuum frying. Furthermore, more uniform porosity was observed on the vertical cross‐section of carrot chips when examined by scanning electron microscopy. During vacuum frying, the moisture content, colour and breaking force of carrot chips decreased while the oil content increased with increasing frying temperature and time. However, there was no apparent change in Hunter ΔE with time when the frying temperature was below 100 °C and the frying time was below 25 min. Results of this study suggest that vacuum frying at moderate temperature (90–100 °C) for 20 min can produce carrot chips with lower moisture and oil contents as well as good colour and crispy texture. Copyright © 2005 Society of Chemical Industry     

真空油炸胡萝卜脆片基本特性的研究

真空油炸技术可用于生产高品质的果蔬脆片．主要研究了油炸温度和真空度对胡萝卜片水分质量分数、脂肪质量分数、色泽及质构的影响．试验表明：随着油炸温度和真空度的升高，其干燥和脂肪吸收速度相应提高，且两者呈一定的相关性．统计分析可知：油炸温度和真空度并不显著性影响脆片的白度（L）、红度（a）、黄度（b）值（P〉0．05）；对于脆片的破碎力而言，真空度具有显著性影响（P〈O．05），而油炸温度不具有显著性影响（P〉0．05）．     

低温真空油炸薯片生产工艺及其贮藏条件的研究

对马铃薯片进行低温真空油炸生产工艺的基础性研究,分析薯片在贮藏过程中水分、脂肪和VC含量的变化,并探讨等温吸湿规律。通过单因素试验确定最优的油炸工艺参数为温度105℃,时间20min,真空度0.090MPa;离心脱油的最佳条件为脱油转速400～500r/min,时间5～7min,真空度0.090MPa。研究结果对低温真空油炸薯片技术具有很好的指导和促进作用,同时改善了现在油炸薯片的品质和提高了能源利用率。     

常压煎炸和真空煎炸对中国对虾品质的影响

探究常压煎炸和真空煎炸对中国对虾理化性质和感官品质的影响。测定了不同煎炸温度下两种煎炸方式对中国对虾的水分含量、含油量、色泽、虾青素含量和感官品质的影响。结果表明：随着煎炸温度的升高,两种煎炸方式下中国对虾的水分含量均降低,含油量均增加,但真空煎炸下中国对虾的变化幅度较低;两种煎炸方式下中国对虾的虾青素含量均随着煎炸温度的升高呈现先增加后减少的趋势;相同热驱动力下,真空煎炸的中国对虾的色泽、虾青素含量和感官品质均优于常压煎炸的。相比于常压煎炸,真空煎炸的中国对虾品质更佳。     

Optimization of processing conditions for vacuum frying of high quality fried plantain chips using response surface methodology (RSM)

Optimization of processing conditions (temperature 122 to 136°C, vacuum pressure 9.91 to 19.91 cmHg, and frying time 3 to 9 min) during vacuum frying of plantain chips was investigated using a Box-Behnken experimental design with response surface methodology (RSM). Models for various responses were developed and optimized frying conditions using numerical solutions were established. Optimized vacuum fried samples were compared with atmospheric fried samples based on the concept of equivalent thermal driving force (ETDF). Frying parameters had significant (p<0.05) effects on the moisture content, texture, and color with a coefficient of determination (R ²) for quadratic model responses varying between 0.53 and 0.99. Optimum vacuum frying conditions for plantain chips were a frying temperature of 133°C, vacuum pressure of 9.91 cmHg, and frying time of 6 min based on desirability concepts. Vacuum fried plantain chips had more acceptable sensory properties, based on ETDF values, than atmospheric fried samples.     

Effects of osmotic pretreatment and frying conditions on quality and storage stability of vacuum-fried pumpkin chips

The effects of osmotic (OP), ultrasound-assisted osmotic pretreatment (UAOP) and frying conditions on quality and storage stability of vacuum fried pumpkin chips were investigated. The pumpkin samples were pretreated in maltodextrin solution and subsequently fried at different temperatures (90–110 °C) and time periods (10–30 min). The results demonstrated that the moisture content, water activity, lightness, yellowness and carotenoid content of the fried chips decreased, while oil content, hardness and a* (dark brown colour) value increased with increasing frying temperature and time. UAOP reduced about 16.0% of oil absorption and enhanced approximately 70% of carotenoid retention in the fried chips. UAOP samples were also more stable during storage than the untreated ones, indicated by lower degradation kinetics constants of key quality parameters. The proposed pretreatment could be an effective method for food industries to develop vacuum fried pumpkin chips with improved quality and stability.     

The optimization of vacuum frying to dehydrate carrot chips

The effects of pretreatment and processing conditions, such as frying temperature, absolute vacuum pressure and frying time; on the properties of fried carrot chips were studied. Statistical analysis with response surface regression showed that moisture content, fat content and breaking force of carrot chips were significantly (P < 0.05) correlated with frying temperature, vacuum absolute pressure and frying time. The optimum conditions were a vacuum frying temperature of 100–110 °C, a vacuum absolute pressure of 0.010–0.020 MPa and a frying time of 15 min.     

Vacuum frying as a route to produce novel snacks with desired quality attributes according to new health trends

Consumers look for products that contribute to their wellness and health, however, even health-conscious consumers are not willing to sacrifice organoleptic properties, and intense full-flavor snacks remain an important trend. The objective of this study was to examine most important quality parameters of vacuum (1.92 inHg) and atmospheric-fried carrot, potato, and apple slices to determine specific advantages of vacuum technology. Slices were fried using equivalent thermal driving forces, maintaining a constant difference between oil temperature and the boiling point of water at the working pressure (ΔT = 60 and 80 °C). This resulted in frying temperatures of 160 and 180 °C, and 98 and 118 °C, for atmospheric and vacuum frying, respectively. Vacuum-fried carrot and potato chips absorbed about 50% less oil than atmospheric-fried chips, whereas vacuum-fried apple chips reduced oil absorption by 25%. Total carotenoids and ascorbic acid (AA) were greatly preserved during vacuum frying. Carrot chips vacuum fried at 98 °C retained about 90% of total carotenoids, whereas potato and apple slices vacuum fried at 98 °C, preserved around 95% of their initial AA content. Interestingly, results showed that the antioxidant capacity of chips may be related to both the presence of natural antioxidants and brown pigments developed at elevated temperatures. PRACTICAL APPLICATION: A way to reduce detrimental effects of deep-fat frying is through operating-pressure reduction, the essence behind vacuum deep-fat frying. In this way, it is possible to remove product moisture at a low temperature in a low-oxygen environment. The objective of this research was to study the effect of oil temperature reduction when vacuum frying traditional (potatoes) and nontraditional products (carrots and apples) on most important quality attributes (vitamins, color, and oil uptake). Results are promising and show that vacuum frying can be an alternative to produce nutritious and novel snacks with desired quality attributes, since vitamins and color were greatly preserved and oil absorption could be substantially reduced.