Rui M.S. Cruz

Methods in food analysis

This book reviews methods of analysis and detection in the area of food science and technology. Each chapter deals with determination/quantification analyses of quality parameters in food, covering topics such as lipids, color, texture, and rheological properties in different food products. The book focuses on the most common methods of analysis, presenting methodologies for specific work conditions. It provides a reference for food engineers and researchers working in the area of food science and technology as well as undergraduate and postgraduate students.

Mathematical modeling of gallic acid release from chitosan films with grape seed extract and carvacrol

Controlled release of antimicrobial and antioxidant compounds from packaging films is of utmost importance for extending the shelf-life of perishable foods. This study focused on the mathematical modeling of gallic acid release into an aqueous medium from three chitosan films, formulated with grape seed extract (GSE) and carvacrol. We quantified the release by HPLC technique during 30days at three temperatures (5, 25 and 45°C). The diffusion coefficients, varying with temperature according to an Arrhenius-type relationship, and the respective activation energies for Film-1 and Film-2 were, respectively [Formula: see text] m2s-1 and [Formula: see text] m2s-1, Ea1=58kJmol-1 and Ea2=60kJmol-1 as obtained from the Fickian fit. The low concentrations of gallic acid released by Film-3 could not be detected by HPLC, therefore the respective diffusion coefficient was not estimated. This study will help with the development and optimization of active packaging (AP) films aiming at improved food preservation and shelf-life extension.

New Food Packaging Systems

Abstract The increasing consumer demand for safe, minimally processed, and extended shelf life high-quality foods has stimulated the search for innovation in the area of food packaging. Companies need to adapt and find ways to improve their productivity, taking also into account the environmental impact of their new solutions. Active packaging is one of the new food packaging systems that may use biodegradable materials; importantly, the packaging interacts with the food product, changing its conditions, increasing its shelf life, safety, and quality, or improving its sensory characteristics. Intelligent packaging is another innovative food-packaging system that uses sensors and/or devices to monitor the food products and display the relevant information, improving product safety, and extending its shelf life. This chapter discusses active and intelligent food-packaging systems, including the film-forming materials and methods used to develop each package, its design, the relevant physical and mechanical properties, and finally, the types of food that benefit more from using such packaging systems.

Chapter 11 – Extraction of Bioactive Compounds From Olive Leaves Using Emerging Technologies

Abstract Olive leaves are a residue from the olive-oil industry and usually are discarded or used as feed for livestock. However, olive leaves are sources of added value bioactive compounds that can be used in the pharmaceutical, cosmetic, and food industries. Several conventional methods are available in the literature regarding the extraction of valuable compounds from plant matrices. In the last few years, new extraction techniques have been studied to reduce the volume of solvents required to extract those types of compounds. The chapter discusses these extraction techniques, including microwave, supercritical fluid, superheated liquid, and ultrasound, which are being used to extract bioactive compounds from olive leaves, as well as their antioxidant and antimicrobial properties.