Influence of bunch maturation and chemical precursors on acrylamide formation in starchy banana chips

The present study investigated the effect of ripening stages and chemical precursors on acrylamide formation in deep-fried chips of five plantains and one cooking banana. The highest level of acrylamide was found in the cooking banana, followed by False Horn plantain and French plantain, respectively. French plantain hybrids exhibited a significantly lower (P < 0.05) level of acrylamide when compared to French plantain. The ripening stage demonstrated a positive Pearson correlation (P < 0.05, r = 0.57) with acrylamide formation. As ripening progressed, the levels of glucose and fructose significantly increased (P < 0.05) and showed a positive correlation with acrylamide formation (r = 0.85 and 0.96, respectively). The level of the amino acid asparagine during ripening was not correlated with acrylamide formation. In contrast, the level of histidine, arginine, iso-leucine and cystine during ripening was positively correlated (P < 0.05, r > 0.60) with acrylamide formation in fried chips. The higher level of TP was significantly related (P < 0.05) to the lower level of acrylamide (r = −0.62). The reduced levels of carotenoid isomers, except lutein, during fruit ripening were positively correlated (P < 0.05) with acrylamide formation, especially trans-BC (r = 0.72) and 9-cis-BC(r = 0.64).     

Studies on long-term storage stability of biodiesel (B100) and its blend (B20) using Box-Behnken response surface method

The gradual depletion of fossil fuels has greatly enhanced the necessity to look for alternative fuels for automobile engines. In response to this, biodiesel is being considered as a promising and potential alternative substitute to conventional petroleum diesel. However, long-term storage stability of biodiesel is poorer compared to conventional petroleum diesel. The aim of the project work is to study the long-term storage stability of biodiesel (B100) and its blend (B20) prepared from used frying oil in different conditions of storage. In this work, the effect of antioxidants and temperature on long storage stability of biodiesel obtained from with respect to storage period is analysed using response surface methodology (RSM). The long storage of biodiesel obtained from used frying oils were optimised by varying parameters such as antioxidant concentration, storage period by Box-Behnken RSM. The properties such as the acid value and the viscosity of biodiesel were initially measured. The results of the investigation showed that the addition of sufficient concentration of antioxidant (pyrogallol) significantly maintains the acid value and viscosity of biodiesel and helps to store for a longer storage period at the given storage temperature.     

Antioxidant effects of gallic acid alkyl esters of various chain lengths in oyster during frying process

The antioxidant effects of gallic acid (GA) and its alkyl esters including methyl gallate, ethyl gallate, propyl gallate, butyl gallate (GA-C4), octyl gallate, lauryl gallate, hexadecyl gallate and octadecyl gallate in frying oil (soybean oil) and oyster during frying were investigated. Rancimat induction period (RIP) assay indicated GA and its alkyl esters effectively improved the oxidative stability of soybean oil according to the ‘polar paradox’; that is, the antioxidant effects of the polyphenols decreased in lipid system with the increasing of hydrophobicity. Results also indicated that GA and its alkyl esters all effectively retarded lipid oxidation in oyster tissue according to parameters including RIP, peroxide value and electron spin resonance assays. Moreover, the antioxidant efficiency in oyster increased with the alkyl chain length until GA-C4, and thereafter, the antioxidant effects decreased, similar to the ‘cut-off effect’. This study provides basic data for improving the oxidative stability of seafood during frying.     

Evaluation of the effect of a novel membrane filtration system on the lifespan of frying oil

Frying oil has a limited lifetime which results in the disposal of approximately 67% of all used oil. The aim of this study is to determine the suitability of different membranes for purifying frying oil and investigate the application of continuous membrane filtration in a commercial deep fryer. Eleven different membranes were tested to assess their suitability for filtrating frying oil. A prototype continuous filtration system with an integrated membrane filter was developed for a deep fryer to assess the effect of continuous membrane filtration on oil degradation. The prototype was subjected to a frying test over 13 days and the results compared to those from a standard deep fryer. The prototype maintained total polar compounds (TPC) at an acceptable level of <12% and the oil remained light in colour even after more than 280 h of use, while TPC in the standard deep fryer rose to >27%.     

A Comparative Study of Physicochemical and Flavor Characteristics of Chicken Nuggets during Air Frying and Deep Frying

Chicken nuggets were air-fried and deep-fried for various times at the same temperature. The moisture content, oil content, color, texture, volatile compounds, and lipids degradation of the chicken nuggets were investigated. The evolution rate of the moisture content, oil content, color, and texture were much higher during deep frying than during air frying. Air frying required more time to produce similar quality attributes as those of deep-fried chicken nuggets. On average, the oil content of the air-fried chicken nuggets was 25% lower than that of the deep-fried chicken nuggets. Of the 74 volatile compounds identified in the fried chicken nuggets, aldehydes, hydrocarbons, and heterocycles were the main flavor contributors. The total amount of volatile compounds and aldehydes detected in the air-fried chicken nuggets was much lower than that in the deep-fried samples, but the number of heterocycles produced by the Maillard reaction was higher during air frying. Sensory evaluation revealed that the air-fried chicken nuggets had lower oiliness and crispness, and 9 min was the optimal frying time to obtain air-fried chicken nuggets with similar sensory attributes (color, odor, juiciness, and overall acceptance) as those of the best deep-fried chicken nuggets. Air frying was a healthier frying method for the production of fried chicken nuggets, which could reduce oxidative degradation of lipids in chicken nuggets.     

油煎工艺条件对香煎大麻哈鱼品质的影响

以黑龙江特色菜肴"香煎大麻哈鱼"为研究对象,主要探究不同油煎温度(145,150,155,160,165℃)和时间(6,7,8,9,10min)对香煎大麻哈鱼品质的影响。通过单因素试验分别对香煎鱼肉的剪切力、出品率、水分含量和感官质量进行测定,筛选出最佳的加热工艺。结果表明,香煎大麻哈鱼最佳的油煎条件为在油温155℃时油煎8min,此时鱼肉最嫩,出品率较高,水分含量最大,感官评价得分最高,表现为肉质多汁性、口感等感官品质最佳。