Applications of spray-drying in microencapsulation of food ingredients: An overview

Basic characteristics of the liquid-glass transition are reviewed, emphasizing its universality and briefly summarizing the most popular phenomenological models. Discussion is focused on a number of alternative models which one way or the other connect the fast and slow degrees of freedom of viscous liquids. It is shown that all these ``elastic'' models are equivalent in the simplest approximation.

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Colloquium : The glass transition and elastic models of glass-forming liquids

Encapsulation efficiency and oxidative stability of flaxseed oil microencapsulated by spray drying using different combinations of wall materials

Natural emulsifiers - Biosurfactants, phospholipids, biopolymers, and colloidal particles: Molecular and physicochemical basis of functional performance.

Progress in developing spray-drying methods for the production of controlled morphology particles: From the nanometer to submicrometer size ranges

Most low water content or frozen food products are partly or fully amorphous This review will discuss the extent to which it is possible to understand and predict their behavior during processing and storage, on the basis of glass transition temperature values (Tg) and phenomena related to glass transition Two main conclusions are provisionally proposed Firstly, glass transition cannot be considered as an absolute threshold for molecular mobility Transport of water and other small molecules takes place even in the glassy state at a significant rate, resulting in effective exchange of water in multi-domains foods or sensitivity to oxidation of encapsulated materials Texture properties (crispness) also appear to be greatly affected by sub-Tg relaxations and aging below Tg Secondly, glass transition is only one among the various factors controlling the kinetics of evolution of products during storage and processing For processes such as collapse, caking, crystallization, and operations like drying, extrusion, flaking, Tg data and WLF kinetics have good predictive value as regards the effects of temperature and water content On the contrary, chemical/biochemical reactions are frequently observed at temperature below Tg, albeit at a reduced rate, and WLF kinetics may be obscured by other factors

Glass Transition and Food Technology: A Critical Appraisal

Many texture studies have been published on crispness because of the great interest of consumers towards crispy foods. This work reviews the existing literature on the topic, and especially the different approaches, instrumental and sensory, applied to study crispness. These studies result in a wide range of data but, because crispness is not a clearly defined sensory attribute, the conclusions that can be drawn from these studies should be carefully examined. The physical basis for crispness are discussed and the role of structure, hydration and ingredients on crispness and its stability are presented.

Crispness: a critical review on sensory and material science approaches

Properties of spray-dried food flavours microencapsulated with two-layered membranes: Roles of interfacial interactions and water

This study aimed at evaluating the potential of pectin combination with pea protein isolate (PPI) in the microencapsulation of polyunsaturated fatty acids (PUFA)-rich oil by spray drying, in order to maximize encapsulation efficiency and minimize lipid oxidation The feed emulsions used for particle production consisted of PUFA-rich oil droplets coated by either PPI (primary emulsion) or PPI–pectin (secondary emulsion) Dry emulsions characteristics and oxidative stability of microencapsulated oil as a function of relative humidity (RH; from 11 % to 75 %) were determined Scanning electron microscopy (SEM) images revealed considerable structural changes Oil droplets retained their shape upon drying and reconstitution However, a shift in oil droplet size upon reconstitution indicated that oil droplet coalescence occurred within the process Oxidation of microencapsulated oil in secondary emulsion was delayed from that of primary emulsion but followed the same pattern with regards to humidity A high rate of oxidation was found for intermediate RH conditions (33 % and 57 % RH) The lowest rate of oxidation as followed by hydroperoxide and thiobarbituric acid reactive substances values was found at 75 % RH, a condition that is likely to diverge significantly from the monolayer moisture value The oxidative stability of encapsulated oil was influenced by both physical state of the emulsions and the different constituents at the oil-in-water interface with PPI–pectin secondary emulsion giving the best protection of the oil

Gaëlle Roudaut

Papers

Applications of spray-drying in microencapsulation of food ingredients: An overview

Glass Transition and Food Technology: A Critical Appraisal

Crispness: a critical review on sensory and material science approaches

Properties of spray-dried food flavours microencapsulated with two-layered membranes: Roles of interfacial interactions and water

Encapsulation and Oxidative Stability of PUFA-Rich Oil Microencapsulated by Spray Drying Using Pea Protein and Pectin