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Vacuum frying is one option for producing fried products. Banana blossom is a by-product from banana production that has potential to be processed into food products due to its nutritional value, health benefits and abundance. The objective of this study is to investigate some properties of fresh banana bracts and determine effect of frying conditions on properties of fried banana bracts using a vacuum fryer. After its proximate composition analysis, the banana bracts were vacuum fried (86.65 kPa) at 100, 110 and 120 °C for 10, 15 and 20 min. The suitable frying temperature and time was then selected for studying the appropriate centrifugation conditions at 600, 1,200, and 1800 rpm for 1, 3, and 5 min. Higher frying temperature and longer time resulted in fried banana bracts with higher fat but lower moisture content. Moreover, different centrifugation speed and time yielded significant differences in fried banana bracts properties. The ideal frying condition was frying at 100 °C for 20 min followed by centrifuging at 1800 rpm for 5 min. This frying condition yielded fried banana bracts with the lowest fat, less broken pieces, low moisture while retaining its phenolic composition and antioxidant activity. Its chemical and microbiological properties were standard compliant. • Crispy vacuum fried banana bracts were first time developed. • Suitable frying and centrifuging conditions retained antioxidant level and activity. • Abundant underutilized banana blossom can be value-added into fried snacks. • Vacuum frying is a suitable process of banana bracts fried products. [ABSTRACT FROM AUTHOR]

Concern for the nutritional quality of chips is growing due to rising consumption, motivating research and development of new snack products that contribute to a lower calorie and fat intake in the diet while retaining their good flavor and facility of consumption. The objective of this study was to investigate the behavior of cassava chips, blanched or unblanched and processed under either atmospheric or vacuum frying conditions, in order to determine the influence of these treatments on mechanical and acoustic parameters, optical properties and oil absorption. Vacuum frying trials (17 kPa) were conducted at 120, 130 and 140 °C and compared with frying at atmospheric pressure (101.3 kPa) at 165 °C. Pre-blanching brings a considerable improvement in the color of the vacuum-treated samples and less oil absorption. Vacuum frying pre-blanched cassava chips may be an alternative to atmospheric frying since it improves the color of the samples, reduces the oil gain and maintains crispness. The treatment at 130 °C under vacuum conditions after pre-blanching achieved the best results. [ABSTRACT FROM AUTHOR]

Vacuum frying (VF) was tested as an alternative technique to produce high-quality fried food. This study investigated the effects of oil temperature on the moisture loss, oil uptake, texture, color, and acrylamide content of vacuum-fried versus atmospheric-fried breaded shrimps. The moisture loss and oil absorption of breaded shrimps during VF were significantly affected ( p < 0.05) by oil temperature. Oil absorption was directly proportional to moisture loss during VF. The oil absorption of breaded shrimps during VF increased with increasing temperature for the same frying time. After 10 min of frying, the oil contents of breaded shrimps fried at 80 °C, 100 °C, and 120 °C under vacuum conditions were 0.20 ± 0.013, 0.23 ± 0.012, and 0.25 ± 0.019 g oil /g dry solid , respectively. These values were significantly lower than those (0.32 ± 0.019 g oil /g dry solid ) obtained under atmospheric conditions (170 °C). VF effectively decreased the acrylamide content of breaded shrimps. Furthermore, breaded shrimps with desirable color and low hardness can be produced using VF. These results indicate that VF is a feasible alternative technique to produce high-quality breaded shrimps. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this research was to study the quality attributes of vacuum and atmospheric dried carrot snacks, as well as their sensory map compared to atmospheric and vacuum fried samples, to understand their potential as a healthy snack. Carrot slices were dehydrated until they reached a water activity of 0.44. Atmospheric drying was done in two-steps (100 °C, 10 min followed by 80 °C, 110 min), whereas vacuum drying (6.5 kPa) was carried out at 60 °C, to provide a product with the required water activity in 2 h, as in atmospheric drying. Vacuum (6.5 kPa) and atmospheric frying were carried out at 98 and 160 °C, respectively. Dried products were compared in terms of color, carotenoids content, Maillard reaction occurrence and texture. A flash-profile test was performed to evaluate sensory attributes of dried and fried snacks. Carotenoids retention and color were similar for atmospheric and vacuum dried products, but, texture was negatively affected in vacuum dried ones. Regarding sensory perception, vacuum inclusion had a better effect in frying compared to drying. As a final point, some instrumental analyzes were successfully related to sensory evaluation, and therefore, could be used as a good proxy in future studies. [Copyright &y& Elsevier]

Abstract: The objective of this research was to determine the kinetics of water loss and oil uptake during frying of pre-treated potato slices under vacuum and atmospheric pressure. Potato slices (diameter: 30mm; width: 3mm) were pre-treated in the following ways: (i) raw potato slices “control”; (ii) control slices were blanched in hot water at 85°C for 3.5min; (iii) blanched slices were dried in hot air until reaching a moisture content of ∼0.6g water/g dry basis. The slices were fried under vacuum (5.37kPa, absolute pressure, at 120, 130 and 140°C) and atmospheric conditions (at 180°C). Two models based on the Fick''s law were used to describe water loss: (i) with a constant effective diffusive coefficient; and (ii) with a variable effective diffusive coefficient. Oil uptake data were fitted to an empirical model, with a linear behavior for short times whereas the model was time independent for long times. The variable diffusivity model better fitted experimental water loss, giving values of effective diffusivity between 4.73×10−9 and 1.80×10−8 m2/s. The proposed model for the study of the kinetics of oil uptake fitted the experimental data properly. Control and blanched vacuum fried potato chips increased their final oil contents to 57.1% and 75.4% respectively, when compared with those fried at atmospheric pressure. However, the oil absorption of dried vacuum fried potato chips diminished by ∼30%. [Copyright &y& Elsevier]

Abstract: The objective of this research was to study the effect of different processing conditions on physical and sensory properties of potato chips. Potato slices of Desirée and Panda varieties (diameter: 30mm; thickness: 3mm) were pre-treated in the following ways: (i) control or unblanched slices without pre-drying; (ii) blanched slices in hot water at 85°C for 3.5min and air-dried at 60°C until a final moisture content of ∼0.6kg water/kg dry solid; (iii) control slices soaked in a 3.5kg/m3 sodium metabisulphite solution at 20°C for 3min and pH adjusted to 3. Pre-treated slices were fried at 120 and 140°C under vacuum conditions (5.37kPa, absolute pressure) and under atmospheric pressure until they reached a final moisture content of ∼1.8kg water/100kg (wet basis). An experimental design (3×23) was used to analyze the effect of pre-treatment, potato variety, type of frying and frying temperature over the following responses: oil content, instrumental color and texture and sensory evaluation. Vacuum frying increased significantly (p <0.05) oil content and decreased instrumental color and textural parameters. Sensory attributes, flavor quality and overall quality, were significantly improved using vacuum frying. The higher frying temperature (140°C) increased ΔE, maximum breaking force, hardness and crispness and decreased L * and b * values. On the other hand, Panda potato variety improved the color of the product. A great improvement on color parameters was obtained using sulphited potato slices instead of the other pre-treatments. Although, the better flavor was obtained for control potato chips, no significant differences were found for overall quality between control and sulphited potato chips. Significant correlations (p <0.01) between sensory and instrumental responses were found. [Copyright &y& Elsevier]

Abstract: Sweet potato, green beans, Tommy Atkins mango, and blue potato were fried in a vacuum frying process at a temperature of 120–130±1°C. Before frying, green beans and mango slices were soaked in a 50% maltodextrine 0.15% citric acid solution. The products were also fried in a traditional (atmospheric pressure) fryer at 160–165±1°C for 4 min. A 30-member consumer panel rated the sensory quality of both types of fried snacks using a 1–9 hedonic scale. Compared with traditional frying, oil content of vacuum-fried sweet-potato chips and green beans was 24% and 16% lower, respectively. Blue potato and mango chips had 6% and 5% more oil, respectively, than the traditional-fried samples. Anthocyanin (mg/100 g d.b.) of vacuum-fried blue potato chips was 60% higher. Final total carotenoids (mg/g d.b.) were higher by 18% for green beans, 19% for mango chips, and by 51% for sweet-potato chips. Sensory panelists overwhelmingly preferred (p <0.05) the vacuum-fried products for color, texture, taste, and overall quality. Most of the products retained or accentuated their original colors when fried under vacuum. The traditional-fried products showed excessive darkening and scorching. These results support the applicability of vacuum frying technology to provide high-quality fruit and vegetable snacks. [Copyright &y& Elsevier]

Fried fish skins are snacks with rich flavor in Asian. However, the high fat content about 50% is not good for health. It is possible to reduce the oil content while maintain its fried taste and texture by optimized frying methods. The effects of different frying approaches such as air frying, vacuum frying, electrostatic frying and traditional deep-fat frying on the oil uptake, moisture loss, breaking force, color, and microstructure attributes of fried fish skins were studied. Air and oil frying were performed at 180 °C for 2–12 min. Vacuum frying was conducted at lower temperature 120 °C for 4–24 min. Results showed that air fried and vacuum fried fish skins had the lowest fat contents (9.8% and 27.7%, respectively) and showed smooth, uniform microstructures. On the contrary, holy, irregular and non-uniform microstructures were obtained by traditional deep-fat frying and electrostatic frying due to high heat and rapid mass transfer occurred. The oil uptake (47.6% and 46.3% fat content, respectively) and browning reactions were also significant. Air frying developed a slower water evaporation rate and higher fish skin puffing ratio, which was suggested to be an alternative to traditional deep-fat frying. • Air and vacuum frying significantly reduce oil content of fish skin but take more time. • Air and vacuum frying obtained 73% and 39% less fat than deep-fat fried fish skin. • Kinetic equations for water loss and oil uptake for fried fish skin are established. • Negative relationship between oil absorption and water loss during frying was found. [ABSTRACT FROM AUTHOR]