Optimization of Blanching Conditions Prior to Deep Fat Frying of Yam Slices

Optimization of the Frying Temperature and Time for Preparation of Healthy Falafel Using Air Frying Technology

Air-frying is an innovative technique for food frying that uses hot air circulation to prepare healthy products. The objectives of this study were to establish simplified models to reflect the efficacy of the air frying process at varying temperatures and times on the quality attributes of falafel, and to optimize the frying conditions for producing air-fried falafel. Moisture content, color, fat content, hardness, and sensory evaluation of the fried falafel were analyzed under varied temperatures (140 °C, 170 °C, and 200 °C) and time periods (5 min, 10 min, and 15 min). Statistical analysis was then applied to obtain the best fit model that can describe the properties of fried falafel. Results indicated that moisture content, fat content, and L*-value of air-fried falafel were adversely related to the frying temperature and time, but the hardness and ΔE of fried falafel were increased as the frying temperature and time increased. Moreover, an increase followed by a decrease was shown for the appearance, aroma, crispness, taste, and overall preference scores with the increase in frying temperature and time. The regression analysis showed that the proposed models could be properly used for predicting the properties of the fried falafel. In addition, the overlaid plots resulted in the optimum frying temperature of 178.8 °C and time of 11.1 min. Interestingly, the fat content of the air-fried falafel reduced by 45% at optimal frying conditions compared with that for the deep-fat fried one at 180 °C for 7 min (control). In comparison, the air-fried falafel was lower in fat content, higher in hardness with more acceptable appearance and crispness scores than deep-fat fried falafel. Such information could be beneficial to the manufacturers of the falafel to produce an optimal and healthy product.

Role of Hydrocolloids in the Structure, Cooking, and Nutritional Properties of Fiber-Enriched, Fresh Egg Pasta Based on Tiger Nut Flour and Durum Wheat Semolina

The aim of this work concerns the manufacturing process of fresh egg tagliatelle labeled as a "source of fiber" based on tiger nut flour and wheat semolina. An attempt to improve the quality attributes and cooking properties of the obtained product was made by means of structuring agents. More specifically, a combination of three hydrocolloids (carboximethylcellulose, CMC; xanthan gum, XG; and locust bean gum, LBG) was tested. A Box-Behnken design with randomized response surface methodology was used to determine a suitable combination of these gums to achieve fewer cooking losses, higher water gain and swelling index values, and better texture characteristics before and after cooking. Positive effects on textural characteristics were observed when incorporating XG into the pasta formulation. Cooking and fiber loss also significantly diminished with the XG-CMC combination over 0.8%. No significant effect was found for the other evaluated parameters. A synergistic interaction between LBG and XG was only significant for the water absorption index. The cooked pasta was considered a source of fiber in all cases.

Effects of two pre-treatments, blanching and soaking, as processing modulation on non-enzymatic browning developments in three yam cultivars from Ghana

Non-enzymatic browning develops in dry-cooked foods and those with high carbohydrate develop acrylamide, a neurotoxin and potential carcinogen. However, some non-enzymatic browning products have reducing properties. We hypothesized that non-enzymatic browning and reducing power, a measure of antioxidant activity, of processed yam are affected by pre-treatment. Peeled yam cultivars (KM, RKD and SO89) in chunks were pre-soaked (0, 3, 6, 12, 18, and 24 h) in distilled water or pre-blanched (0, 1, 2, 3, 4, and 5 min) in steam. Pre-treated samples were deep-fried at 180 °C for 15 min or roasted at 220 °C for 30 min. Soluble solids, titratable acidity and pH of yam tissues and soaking water were determined. pH of the soaked yam tissues showed a positive relation with non-enzymatic browning. Pre-soaked fried KM and roasted RKD showed a significant decrease in non-enzymatic browning intensities. The reducing power of the cooked yams ranged between 78.94 and 185.92 % of ascorbic acid, and was affected by the different pre-treatment and dry-cooking methods.

Conventional Processing Affects Nutritional and Antinutritional Components and In Vitro Protein Digestibility in Kabau (Archidendron bubalinum)

Kabau, an unexplored crop, was analyzed to determine its nutrition and antinutrition components and in vitro protein digestibility (IVPD). Some conventional processes, such as steaming, frying, and boiling, were carried out to study their effect. The results indicated that all of the techniques reduced carbohydrate content. Frying significantly increased the fat content of Kabau and reduced other nutritional components. In general, all the methods significantly reduced phytic acid, tannin, and trypsin inhibitors, as much as 94.95–96.26%, 20–35%, and 89.22–92.88%, respectively. The reduction of antinutritional components resulted in higher IVPD on boiled and steamed Kabau, 69.47% and 61.48%, respectively.

Kinetics of moisture loss and oil uptake during deep fat frying of Gethi (Dioscorea kamoonensis Kunth) strips

Investigation was carried out to study kinetics of moisture loss, oil uptake and tristimulus colour during deep fat frying of Gethi (Dioscorea kamoonensis kunth) strips. Deep fat frying of Gethi strips of size 6 × 6 × 40 mm was carried out in a laboratory scale fryer at different temperatures ranging from 120 to 180 °C. The investigation showed that the moisture loss and oil uptake followed the first order kinetics equation (r > 0.95, p < 0.05). The kinetic coefficients for moisture loss and oil uptake increased significantly (p < 0.05) with temperature from 0.166 to 0.889 min(-1) and 0.139 to 0.430 min(-1) respectively. The temperature dependency of rate constants for moisture loss and oil uptake values was described using Arrhenius equation (r > 0.99, p < 0.01). The activation energies for moisture loss and oil uptake were found to be 41.53 KJ/mol and 27.12 KJ/mol respectively. The hunter colour parameters were significantly affected by frying temperature and frying time. The hunter lightness (L) value increased with respect to frying time initially, followed by decline and same trend was observed at higher temperatures of frying with elevated rate, whereas hunter redness (a) value increased significantly (p < 0.01) with time as well as temperature of frying and obeyed zero order rate equation. The temperature dependency kinetic coefficients of Hunter (a) value were described by Arrhenius equation and the energy of activation for change in hunter redness was found to be 42.41 KJ/mol (r > 0.99, p < 0.01). The other hunter colour parameters such as chroma, hue angle and total colour difference were markedly affected by frying temperature as well as frying time.