Example Of Flow Diagram: Vacuum Frying For Fruit And Vegetable
(Setyawan et al., 2013).
A vacuum frying system consists of three components, namely: a vacuum frying chamber, a refrigerated/water-cooled condenser and a vacuum pump (Diamante, 2015).
According to Setyawan et al. (2013), frying temperature, vacuum pressure and frying time varies for different products. For high moisture fried products, additional moisture should be removed by pressing and observing the soft texture. These products are required to undergo the frying process again to obtain a low water content and desired crispiness. For retail packaging, sealed containers should be used to prevent moisture transfer such as aluminum foil bags, aluminum foil bags in a paper box or aluminum foil paper.
China Pantent CN101756113 B (2012) stated that the vacuum frying temperature for green soybean is from 75-80 °C for 95-120 minutes. Whereas, the temperature for vacuum frying mango chips is around 80°C for 45 minutes and is the best yield that produces low water content and good organoleptic chips (Sulistyaningrum, 2012).
Longer shelf life can be obtained when using nitrogen gas packaging. According to Piamkhla (2004), the shelf life of vacuum fried ripe bananas can go up to six months when packaged in a plastic bag that can be flushed with nitrogen or by putting moisture absorbents (Setyawan et al., 2013).
European Patent No. 2293676 A1 (2011) also stated that infusion of fruits and vegetables with prebiotic soluble fibers such as inulin before vacuum frying helps to provide shelf-stable products with reduced water activity and high levels of fiber.
Basker, V. R., & Puppala, V. (2011). Improved infusion method for production of vacuum fried fruit and vegetable snacks. European Patent No. 2293676 A1.
Diamante, L. M., Shi, S., Hellmann, A., & Busch, J. (2015). Vacuum frying foods: products, process and optimization. International Food Research Journal, 22(1), 15-22.
Liu, C. Q., Liu, X., Zuo, C. L., Song, J. F., Li, D. Q. & Jiang, N. (2012). Processing for producing crisp green soybean grains and product thereof. China Pantent CN101756113 B.
Sulistyaningrum, F. (2012). Analysis of physical and organoleptic properties of Mango chips (Mangifera indica L.) processed vacuum frying (Unpublished Diploma’s Thesis). Diponegoro University, Indonesia.
Setyawan, A. D., Sugiyarto, Solichatun, & Susilowati, A. (2013). Review: Physical, physical chemistries, chemical and sensorial characteristics of the several fruits and vegetable chips produced by low-temperature of vacuum frying machine. Nusantara Bioscience, 5(2), 86-103.