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     

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.     

油炸薯片的工艺参数对其产品品质影响的研究

主要研究了油炸薯片的加工工艺,包括切片厚度、烘干时间以及油炸时间、添加剂的种类等对产品品质的影响,尤其是对影响薯片中丙烯酰胺生成的因素进行了重点检测和分析。通过实验最终确定比较合理的工艺条件为:切片厚度1.0～2.0mm;烘干时间50～60min;油炸时间2.0min;添加0.3%CaCl2。     

预处理技术对真空油炸脆蚕豆品质的影响

以慈溪所产大白蚕豆为原料,研究了不同预处理技术,包括浸渍、冷冻以及热风干燥,对真空油炸脆蚕豆品质的影响.结果表明:预处理显著地影响脆蚕豆的水分含量和含油率,且蚕豆初始水分含量与其含油率之间存在显著的相关性.浸渍和热风干燥预处理技术既可以显著地降低产品的含油率,同时,又不影响其脆度和主要色泽值.     

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。     

Effects of raw materials,processing conditions and packaging on the quality of plantain chips

The effects of raw material, processing conditions and packaging on the quality of plantain chips were investigated. Two cultivars of plantain Musa spp—Agbagba and Obino lewai—as well as cooking banana were used for the study. The fruits were at stages 1 to 4 of the banana ripening chart. The study started with a consumer survey aimed at product definition. This was followed by series of experiments to determine the effects of raw material, processing conditions and packaging on the quality of plantain chips. A correlation analysis was also carried out on the physical and chemical characteristics of raw plantain. The work revealed that the stage of ripeness of raw material had some effect on the quality of chips as there was gradual increase in pulp/peel ratio and sugar was significantly different (P < 0·05). Moisture content of pulp/texture of pulp, texture of pulp/sugar content of pulp and texture of pulp/ripening stages were negatively correlated, while pulp/peel ratio and moisture content of pulp were positively correlated. Chips packed in 80 μm high-density polyethylene pouches and stored at various relative humidities had extended shelf-life compared with the low-density polyethylene packed chips stored at the same relative humidities. This was due to the inadequacy of the low-density polyethylene in giving the required protection against moisture transmission thereby resulting in soggy chips in shorter periods. The implication of the findings on the formulation of a guideline for the processing of a good-quality plantain chips for the marketing system is discussed.     

影响油炸薯片品质的工艺参数研究

对影响油炸薯片产品品质的工艺参数进行了研究。结果表明,油炸薯片的最佳工艺条件为：切片厚度控制在1．0～2．0mm,烘干时间为50-60min,油炸时间为2．0min,添加剂为0．3％CaCl2。     

不同烫漂时间对真空油炸毛豆仁品质的影响

对生产中不同烫漂时间对真空油炸毛豆仁品质的影响进行了研究。实验结果表明,烫漂时间的长短(在0-10min内)对真空油炸毛豆仁的脆度、瓣的完整性以及色泽有明显影响,综合比较2-10min处理后产品的Vc含量和蛋白质含量,烫漂时间的长短对产品的营养物质损耗不是很大,烫漂时间对含油率影响较大,超过6min后,含油率下降不是很明显。综合比较表明,烫漂时间6min为最佳。     

The pivotal role of moisture content in the kinetic modelling of the quality attributes of vacuum fried chips

Moisture content plays a pivotal role in the kinetic modelling of the quality attributes during thermal processing of foods. Vacuum frying of mango chips, was chosen to demonstrate the applicability of this novel modelling approach that links a dynamic moisture model to models for changes in fat content, texture, and color. Results show that moisture loss is best described by an exponential model with an Ea of 40.0 ± 4.2 and 27.2 ± 2.3 kJ mol⁻¹ for unripe and ripe mango respectively. The dynamic moisture content was linked to the fat content by a Gompertz model, and to the hardness by an exponential model. By using thermodynamic principles, the moisture model predicts the dynamic local product temperature that can be linked to the reaction rates of the consecutive color change reaction models. The integration of these models is a powerful tool in product and process optimization to produce high quality vacuum fried fruit products.Industrial relevance textFood moisture content changes during many thermal processing techniques but it also plays a pivotal role in changes of the quality attributes of foods. Quality change models were developed that integrate changes in the moisture content with changes in quality attributes. These models can be applied to produce a minimal fat content and low moisture content while getting a desired color change and/or to produce a specific texture characteristics. Moisture dependent models for quality changes are powerful tools for optimizing many other products and process.     

油脂饱和度对油炸马铃薯片品质的影响

以玉米油、花生油、大豆油、大豆棕榈调和油、棕榈油5种不同饱和度油脂作为煎炸用油,以马铃薯片为煎炸内容物,于140℃循环煎炸。考察马铃薯片的油脂含量、水分含量、色泽、酥脆性以及感官评分的变化,综合分析油脂饱和度对油炸马铃薯片品质的影响。结果表明:煎炸油脂的饱和度显著影响油炸马铃薯片的品质(p 0.05),随着煎炸油脂饱和度的增加,油炸马铃薯片的油脂含量呈降低的趋势,水分含量呈增加的趋势,L值呈增大的趋势,表明马铃薯片颜色随着煎炸油脂饱和度的增加而越发鲜亮;油炸马铃薯片的酥脆性、感官评分亦随煎炸油脂饱和度的增加呈显著增加的趋势(p 0.05)。由此可知,相对于不饱和度较高的玉米油、花生油、大豆油,饱和度较高的棕榈油更加适合马铃薯片的煎炸。     

不同真空解冻条件对猪肉品质的影响

该研究以猪前腿肉为研究对象,通过测定猪肉真空解冻的解冻和空气自然解冻速率以及解冻后猪肉的保水性、pH值和猪肉的质地等指标,研究真空解冻在真空度分别为100、500、1000、2000 Pa条件下对冷冻猪肉解冻效果的影响.结果 表明,与空气自然解冻相比,真空解冻的解冻速率明显快于空气解冻,同时能更好地保持解冻后猪肉的品质...     

脱水苹果的非硫护色工艺研究

根据多酚氧化酶的特性，通过正交试验设计并采用国内先进的低温气流膨化技术，获得脱水苹果片的非硫钝酶工艺。     

漂烫对真空油炸银杏果品质的影响

以大佛指银杏果为原料,研究漂烫温度和时间对银杏果POD酶失活时间、水分含量、淀粉糊化度,以及对真空油炸银杏果微观结构、质构、脂肪含量、色泽和感官品质的影响。结果表明:随着漂烫温度和时间的增大,POD酶失活时间逐渐缩短,而银杏果中淀粉糊化度和水分含量逐渐升高;漂烫时间越长真空油炸银杏果的脆性和色泽越好,但真空油炸银杏果的脂肪含量越高;100℃漂烫5min时银杏果真空油炸后能形成多孔状,且感官评分最高。综合考虑,采用100℃条件下对银杏果进行漂烫5min处理。     

抑制鲜切油炸薯片中丙烯酰胺产生的在线控制研究

前期研究表明,半胱氨酸、CaCl2等离子型物质能有效抑制油炸薯片中丙烯酰胺的产生。但在浸泡过程中其浓度会不断降低,因此如何在线监控抑制剂浓度并及时补充成为抑制剂能否成功用于工业化生产的关键。根据抑制剂浓度与电导率之间的线性关系,采用电导率仪监控浸泡液中抑制剂浓度,通过电导率仪获得的数据实时补充抑制剂。     

Effects of food gums and pre-drying on fat content of fabricated fried chips

Deep-frying contributes to the unique taste and texture of fried products. However, they are low in nutritional value. Food industries actively trying to find ways to reduce the fat content while maintaining organoleptic properties of fried foods. In this work, effects of pre-drying and adding food gums on the moisture and fat contents of chips were evaluated. The chips were pre-dried for 60 and 90 min, and gellan gum, guar gum, methylcellulose and xanthan gum were added at the concentration of 0.25, 0.75, 1 and 2 % w/w. The xanthan gum was the most effective gum for fat reduction. The addition of 0.25 % w/w xanthan gum and at 90 min pre-drying reduced the fat content from 20 % (control) to 15 % w/w. The results also indicated that the reduction of moisture content after frying was not affected by the type of gums but the method of pre-drying.     

预处理工艺条件对冻干白萝卜脆片品质的影响

目的? 考察护色、漂烫和磁场辅助冷冻对真空冷冻干燥白萝卜脆片品质的影响。方法 在单因素实验的基础上,以白度、营养成分保留率、硬度、韧性为评价指标,选取护色剂（抗坏血酸）质量浓度、漂烫时间、漂烫温度进行三因素三水平正交实验,确定白萝卜脆片品质最佳的漂烫条件。在此基础上,考察不同强度静磁场（0、0.4、0.8、1.2、1.6 mT）强度对白萝卜的冻结曲线以及冻干白萝卜脆片复水比的影响。结果? 抗坏血酸质量浓度10 g/L、漂烫时间3 min、漂烫温度60℃、静磁场强度0.8 mT辅助冷冻处理,可使真空冷冻干燥白萝卜脆片获得较好的品质。结论 真空冷冻干燥白萝卜脆片的加工过程中,采用适宜的护色、漂烫工艺以及磁场辅助冻结处理,可有效提高产品的品质。本研究可为果蔬脆片的加工以及白萝卜的精深加工和高值化利用提供参考。     

结合数据融合技术与近红外光谱的休闲苹果脆片综合品质评价

以加工过程中的苹果脆片为对象,对其水分、可溶性固形物、总糖、可滴定酸和硬度5个品质指标进行综合分析,得到各指标的权重和脆片品质的综合得分,根据综合得分情况,将脆片分为A(高品质)、B(中品质)、C(低品质)三类。利用近红外光谱技术获取苹果脆片光谱信息,运用偏最小二乘判别分析(partial least-squares discriminant analysis,PLSDA)方法建立基于光谱特征的苹果脆片综合品质得分的判别模型,对3类脆片进行分类的实际值和预测值的相关系数R分别为0.84,0.63,0.89,均方根误差RMSEC分别为0.26,0.34,0.22,预测集样本的判别准确率分别为83.33%,80.0%,93.33%,说明了结合数据融合技术与近红外光谱评价加工过程中苹果脆片综合品质具有较好的可行性。