Effect of Vacuum Frying on Quality Attributes of Fruits

Abstract

Vacuum frying of fruits enables frying at lower temperatures compared to atmospheric frying, thereby improving quality attributes of the fried product, such as oil content, texture, retention of nutrients, and color. Producing high-quality vacuum-fried fruit is a challenge, especially because of the high initial water content of fruits that requires long frying times. Factors influencing vacuum-fried fruit quality attributes are the type of equipment, pre-treatments, processing conditions, fruit type, and fruit matrix. Pre-treatments such as hot air, osmotic drying, blanching, freezing, impregnation, anti-browning agents, and hydrocolloid application strongly influence the final quality attributes of the products. The vacuum-frying processing parameters, namely frying time, temperature, and vacuum pressure, have to be adjusted to the fruit characteristics. Tropical fruits have different matrix properties, including physical and chemical, which changed during ripening and influenced vacuum-fried tropical fruit quality. This paper reviews the state of the art of vacuum frying of fruit with a specific focus on the effect of fruit type and matrix on the quality attributes of the fried product.

Nutritional and Physicochemical Quality of Vacuum-Fried Mango Chips Is Affected by Ripening Stage, Frying Temperature, and Time

“…This is of particular relevance for fruits which contain high amounts of thermolabile vitamins and phytochemicals. In this respect, characteristics of the fruit matrix can play a very important role and is an underexposed factor in the scientific literature up to now (7).…”

Effect of vacuum frying on quality attributes of pear ( Pyrus communis L) chips and blended oil

“…This observation can be explained in the following way. The increase in temperature‐induced degradation of tissue matrix resulted in rapid evaporation of moisture from the product (Ayustaningwarno et al., 2018; Diamante, Savage, Vanhanen, & Ihns, 2012). The rapid moisture loss occurred from the interior of the product (because of higher temperature) leads to an increase in the pore density.…”

“…In the case of conventional frying, tissue matrix degradation of the pear occurs because of higher processing temperature (175°C ± 5°C), during which redness increases (not desired) because of the caramelization of sugars. In addition, rapid evaporation of moisture from the product takes place (Ayustaningwarno et al., 2018; Diamante et al., 2012) leading to an increase in the pore density. Even though a high density of pores is present, because of lower pressure difference, some of the moisture evaporated continues to stay in the pores.…”

“…In this process, frying takes place under vacuum, especially at low pressure. These results in the lowering of the boiling point of moisture and frying temperature of oil (Ayustaningwarno, Dekker, Fogliano, & Verkerk, 2018; Deng, Chen, Tian, Miao, & Zheng, 2019; Shen, Zhang, Bhandari, & Guo, 2018). The absence of oxygen during frying and temperature of frying well below than traditional deep‐fat frying results in the least damage to the frying medium (Juvvi et al., 2016 ) .…”

Mechanisms of oil uptake during deep frying and applications of predrying and hydrocolloids in reducing fat content of chips

“…Vacuum frying is known for enabling to fry at a low temperature and produce high product quality fried fruits by retaining the food colour and nutrient content (Ayustaningwarno et al, 2018). Also, vacuum frying potato chips reduced the fat content by 13% (Su et al, 2018).…”