Kinetics of Moisture Loss and Oil Absorption of Pork Rinds during Deep-Fat, Microwave-Assisted and Vacuum Frying.

Hong-Ting Victor Lin,Der-Sheng Chan,Wen-Chieh Sung,Yu-Hsiang Huang

doi:10.3390/foods10123025

Hong-Ting Victor Lin, Der-Sheng Chan + Show 2 more

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https://doi.org/10.3390/foods10123025

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Abstract

The fat content of fried pork rinds is high, and alternative frying helps reduce the oil content and maintain their texture and taste. Different frying methods such as microwave-assisted, traditional deep frying and vacuum frying on the breaking force, color, microstructure, water loss and oil absorption attributes of fried pork rinds were evaluated in this study. The fat content of microwave-assisted and vacuum-fried pork rinds was lower (24.2 g/100 g dry weight basis (db) and 17.1 g/100 g db, respectively) than that (35.6 g/100 g db) of traditional deep-fat frying. Non-uniform, holy and irregular surface microstructures were obtained by vacuum frying due to rapid mass transfer at low pressure. The first-order kinetic models of water loss and oil absorption of traditional and microwave-assisted frying of pork rinds were established. Microwave frying caused a faster moisture loss rate, shorter frying time and lower pork rind oil content, makes it an attractive substitute for traditional deep-fat frying.

Highlights

Frying is a traditional and straightforward cooking method with a complex process that causes foods to absorb oil/fat and lose water
The microwave-assisted frying method significantly decreased breaking force, optimal frying time (3 min) and oil content (24.2 g/100 g db) of fried pork rinds compared with traditional frying (5 min frying time and 35.6 g/100 g db oil content)
The vacuum frying method decreased the puffing ratio and oil content (17.1 g/100 g db) of fried pork rinds but dramatically increased optimal frying time (20 min) and made the product hard; frying at a lower frying temperature (120 ◦C) resulted in pork rinds that were unsuitable for consumption

Summary

Introduction

Frying is a traditional and straightforward cooking method with a complex process that causes foods to absorb oil/fat and lose water. The high temperature of frying oil, frequently (180–200 ◦C) produces a unique aroma called reaction flavor, including alcohols, aldehydes, carboxylic acids, furans, hydrocarbons, ketones, pyrazines and pyridines, which provides fried food a distinct flavor and taste [2]. Fried pork skin (pork rind) is a widely consumed traditional side dish or snack in Thailand [3]. Consuming fried food is usually related to the risk of health effects, involving diabetes [5], cardiovascular disease [6], hypertension and obesity [7], the consumption of fried foods has increased since many centuries ago. Consumers, food scientists and industries eagerly purchase, invent and generate low-fat snacks that maintain fried products’ appropriate texture and flavor

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