Computational studies on physico-chemical properties in the quality analysis of corn and peanut oil

S Rubalya Valantina,K Arockia Jayalatha

doi:10.3989/gya.0663201

Abstract

Oils are commonly used in cooking as a frying medium which has been constantly subjected to different levels of heating. In this work, we have considered the most commonly used oils namely peanut oil and corn oil. Quality analyses of corn and peanut oils were made by relating macroscopic properties (ultrasonic velocity, viscosity, and density) to microscopic parameters (intermolecular free length, adiabatic compressibility etc.,) by subjecting them to six cycles of heating (190 ˚C). Variation in the mentioned property indexes, the degree of degradation and reusability for the next heating cycle that could be used in the food industry and processing were monitored. Using Newton-Laplace and Wood’s equation, the adiabatic compressibility, acoustic impedance, and intermolecular free length of the oil were estimated from the experimental data. Ultrasonic velocity was observed linearly as related to viscosity with the dependency factor (R2 = 0.932). With the aid of experiential data, the physical thermodynamic parameters, particularly particle size, packing factor, chemical potential, and L-J potential were computed. A high correlation factor was observed by fitting ultrasonic velocity, viscosity, and density to Parthasarathy and Bakshi, and Rodenbush equations. In the study, ultrasonic velocity, a macroscopic parameter, could be decoded to determine the microscopic variations in oil subjected to different temperatures in an industrial application.

Highlights

The ultrasonic technique is a non-destructive method used to estimate the quality of food products such as vegetables, milk, fruits, egg, fish, meat products, etc
Variations in the ultrasonic velocity, density, and viscosity of peanut oil and corn oil samples exposed to different heating cycles at 190 oC were studied
From the physical parameter variations, it is observed that compared to peanut oil, corn oil can be used in more frying cycles

Summary

Introduction

The ultrasonic technique is a non-destructive method used to estimate the quality of food products such as vegetables, milk, fruits, egg, fish, meat products, etc. The estimation of the composition of any food material can be done using ultrasonic waves. Low-intensity ultrasonic waves can be used to evaluate the quality, texture, and compositional changes in fats and oils (Benedito et al, 2002). Ultrasonic velocity through vegetable oil decreases with the increase in temperature and can be illustrated in three different regions (Benedito et al, 2002; Izbaim et al, 2010). A decrease in the ultrasonic velocity in region I (temperature range 0 to 22 °C) exhibits a negative temperature coefficient due to the presence of the polymers monomer, dimer, trimer, and oligomer in the oil. A decrease in the velocity in region III (temperature range 38 to 50 °C approximately) has been observed due to saturated bonds in fatty acids (McClements and Gunasekaran)

Methods

Results

Conclusion