Charis M. Galanakis

The Effects of Conventional and Non-conventional Processing on Glucosinolates and Its Derived Forms, Isothiocyanates: Extraction, Degradation, and Applications

Abstract In recent decades, glucosinolates and isothiocyanates have attracted the interest of scientific community due to healthy properties of these bioactive compounds and their role as natural antimicrobials and anticarcinogenic agents. However, these compounds can lose their properties and transform into antinutrients depending on processing conditions. At this stage of investigation, there is a need in evaluation of the commonly accepted and new emerging methods in order to establish the optimum conditions for preserving healthy glucosinolates and isothiocyanates. This paper reviews the conventional and new promising technologies that can be useful for extraction of appropriate glucosinolates and isothiocyanates from natural sources (i.e., Brassica vegetables). The impact of different preservation processes on degradation of glucosinolates and isothiocyanates is also discussed.

A Knowledge Base for The Recovery of Natural Phenols with Different Solvents

The current study denotes the prediction of activity coefficients of fifteen natural phenols (tyrosol, hydroxytyrosol, oleuropein, caffeic, cinnamic, p-coumaric, ferulic, gallic, p-hydroxybenzoic, p-hydroxyphenyl acetic, protocatechuic, rosmarinic, sinapic, syringic, and vanillic acid) in seven solvents (water, ethanol, methanol, acetone, dichloromethane, ethyl acetate, and diethyl ether), and three extraction temperatures (298.15, 313.15, and 333.15 K), using the universal functional-group activity coefficient model. Solvents were classified for their ability to dissolve phenols and were compared with experimental data of the literature in order to observe if the solvent extraction of phenols in practice matches with the authors’ theoretical approach. Results indicated the superiority of alcohols and acetone for the recovery of phenols in line with experimental data of previous studies. Furthermore, activity coefficients’ values were found to increase with the increase of temperature. This study provided a knowledge base for the selection of the most appropriate solvents for a given phenolic compound.

Phenolic Content and Antioxidant Capacity of Cypriot Wines

Galanakis Ch.M., Kotanidis A., Dianellou M., Gekas V. (2015): Phenolic content and antioxidant capacity of Cypriot wines. Czech J. Food Sci., 33: 126–136. We characterised 12 wines (10 red, 1 sweet red, and 1 white) from different Cypriot cultivars in terms of their phe nolic, anthocyanin composition, and antioxidant capacity as determined by two activities: radical scavenging and ferric reducing ability. Two different phenolic fractions (tannin-free and 1-kDa permeate) were also isolated from Cypriot wines with an ultimate goal of investigating their role in the overall antioxidant capacity of wines. The results indicated that Maratheftiko and Lefkada cultivars had higher concentrations of o-diphenols, hydroxycinnamic acid derivatives, flavonols and anthocyanins compared to other Cypriot cultivars like Ofthalmo, Mavro, and Giannoudi. The higher concentrations of phenols did not always correspond to a higher antioxidant capacity, probably due to the antagonistic action observed between hydroxycinnamic acid derivatives, flavonols, and anthocyanins. The latest interactions restricted the release of flavonols’ advanced antiradical activity in wines.

Effect of pressure and temperature on alcoholic fermentation by Saccharomyces cerevisiae immobilized on γ-alumina pellets

Saccharomyces cerevisiae was immobilized on γ-alumina pellets and used for repeated batch fermentations in glucose medium (16.5 g/100 mL) at various temperatures and pressures. An increase in pressure from 3 to 7 atm and a decrease in temperature from 30 to 20 °C reduced the ethanol productivity by about 50% and 70%, respectively. Increasing concentrations of volatile by-products were observed at lower fermentation temperatures, while the pressure influence on the concentrations of these by-products was proved to be more complex. Mathematical expressions were established to allow the calculation of the fermentation rate at various pressures and sugar concentrations when the corresponding rate at atmospheric pressure is known. The study showed that the height of bioreactors has to be limited to 19.5 m due to hydrostatic pressure shock at higher fill levels.

Enzyme Kinetics Modeling as a Tool to Optimize Food Industry: A Pragmatic Approach Based on Amylolytic Enzymes

Modeling is an important tool in the food industry since it is able to simplify explanation of phenomena and optimize processes that cover a broad field from manufacture to byproducts treatment. The goal of the current article is to explore the development of enzyme kinetic models and their evolution over the last decades. For this reason, corresponding simulations were classified in deterministic, empirical, and stochastic models, prior investigating limitations, corrections, and industrial applications in each case. The ultimate goal is to provide an answer to a major problem: how can we develop an intermediate complexity model that achieves satisfactorily representation of the main phenomena with a limited number of parameters?

Cost and safety issues of emerging technologies against conventional techniques

Abstract The industrialization of recovery processes is governed by several factors such as scale-up boundaries, product safety, and overall cost. Thereby, improved process efficiency is considered in terms of cost minimization via reducing processing steps and restricting overall energy consumption. The emerging nonthermal technologies promise to overcome the obstacles of conventional techniques with regard to energy requirements, but in some cases this has not yet been achievable. In this chapter, an attempt to clarify cost issues of conventional and emerging technologies is conducted. Moreover, other aspects such as safety issues are discussed, as the facilitation of healthy food additive production is a constant need.

Patented and commercialized applications

Abstract The commercialization of high added-value compounds recovery from food wastes deals with several issues such as laboratory research, scale-up problems, protection of intellectual properties, and development of market-destined applications. These issues are described in this chapter wherein a collection of commercially available compounds recovered from food by-products is presented. Verification of market existing products matching with patented processes was conducted using patent applicant name in each case. However, this matching as well as production characteristics may not be correct in all cases, as most companies typically are secretive about their methods of production and respective data cannot be found in the literature. Despite the omnipresence of related studies and patented methodologies, the market existing products derived from food wastes are today rather limited. There are many reasons for this, such as scale-up and commercialization problems, protection of intellectual properties, approval of products’ health claims, etc. All these aspects are discussed in this chapter, wherein a proposal for the establishment of a new label (similar to organic foods) is introduced in order to reveal the potentiality of recovering valuable compounds from food wastes.

Extraction of phytochemicals using hydrotropic solvents

ABSTRACT Every plant synthesizes phytochemicals with different properties to supply a pool of molecules for food, chemical and pharmaceutical applications. Concurrent with “green technology” development, use of green solvents to extract phytochemicals instead of conventional non-eco-friendly solvents is crucial. Hydrotrope is a one of the green solvents that enhances solubility of poorly water-soluble or hydrophobic compounds in aqueous solutions. This article critically reviews the extraction of phytochemicals using various hydrotropic solvents. Hydrotropy mechanisms, factors influencing extraction and recovery methods of phytochemicals were also evaluated in this review.

Chapter 10 – Recovery of bioactive compounds from olive mill waste

For many decades, olive mill wastewater and wet olive pomace considered only as materials of treatment, minimization, and prevention. Today, they deal with the prospect of being utilized as a source for the recovery of bioactive compounds [e.g., phenols, dietary fibers (DFs), so on]. The latest ingredients could be reutilized as additives in foods and cosmetics. This chapter describes the different technologies for the recovery of bioactive compounds from olive oil processing by-products and suggests an integral methodology that ensures the sustainability of the process. The dominant scenario is to pretreat the initial material and convert oleuropein to hydroxytyrosol, prior extracting phenols with solvent and/or other technologies. The applications of membrane processes for this purpose are thoroughly discussed, whereas detail information for the current patented and commercialized methodologies are provided. Finally, future perspectives are denoted.

Chapter 8 – Carotenoids

Numerous epidemiological evidence has shown that the consumption of carotenoid-rich food lowers the risk of chronic diseases including various types of cancer and cardiovascular diseases. Most of the benefits of carotenoids are due to their robust antioxidant effects, which fuel the growth of today’s existing carotenoid-rich formulations. Progress in this field has become challenging due to increasing consumer preferences for nutritious and effectual carotenoid formulas with unmodified sensorial properties. Various new technologies have been developed by food industrialists to acquire and preserve carotenoids from natural sources on a long-term basis. This chapter focuses on the nutritional and functional properties of the main carotenoids as well as the modifications that processing with emerging technologies have brought to the field including their bioaccessibility, stability, and functional properties.