Shahin Roohinejad

Landmarks in the historical development of twenty first century food processing technologies

Over a course of centuries, various food processing technologies have been explored and implemented to provide safe, fresher-tasting and nutritive food products. Among these technologies, application of emerging food processes (e.g., cold plasma, pressurized fluids, pulsed electric fields, ohmic heating, radiofrequency electric fields, ultrasonics and megasonics, high hydrostatic pressure, high pressure homogenization, hyperbaric storage, and negative pressure cavitation extraction) have attracted much attention in the past decades. This is because, compared to their conventional counterparts, novel food processes allow a significant reduction in the overall processing times with savings in energy consumption, while ensuring food safety, and ample benefits for the industry. Noteworthily, industry and university teams have made extensive efforts for the development of novel technologies, with sound scientific knowledge of their effects on different food materials. The main objective of this review is to provide a historical account of the extensive efforts and inventions in the field of emerging food processing technologies since their inception to present day.

Bioavailability of Glucosinolates and Their Breakdown Products: Impact of Processing

Glucosinolates are a large group of plant secondary metabolites with nutritional effects, and are mainly found in cruciferous plants. After ingestion, glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. However, the largest fraction is metabolized in the gut lumen. When cruciferous are consumed without processing, myrosinase enzyme present in these plants hydrolyzes the glucosinolates in the proximal part of the gastrointestinal tract to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. When cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates transit to the colon where they are hydrolyzed by the intestinal microbiota. Numerous factors, such as storage time, temperature, and atmosphere packaging, along with inactivation processes of myrosinase are influencing the bioavailability of glucosinolates and their breakdown products. This review paper summarizes the assimilation, absorption, and elimination of these molecules, as well as the impact of processing on their bioavailability.

Fermentation at non-conventional conditions in food- and bio-sciences by the application of advanced processing technologies

Abstract The interest in improving the yield and productivity values of relevant microbial fermentations is an increasingly important issue for the scientific community. Therefore, several strategies have been tested for the stimulation of microbial growth and manipulation of their metabolic behavior. One promising approach involves the performance of fermentative processes during non-conventional conditions, which includes high pressure (HP), electric fields (EF) and ultrasound (US). These advanced technologies are usually applied for microbial inactivation in the context of food processing. However, the approach described in this study focuses on the use of these technologies at sub-lethal levels, since the aim is microbial growth and fermentation under these stress conditions. During these sub-lethal conditions, microbial strains develop specific genetic, physiologic and metabolic stress responses, possibly leading to fermentation products and processes with novel characteristics. In some cases, these modifications can represent considerable improvements, such as increased yields, productivities and fermentation rates, lower accumulation of by-products and/or production of different compounds. Although several studies report the successful application of these technologies during the fermentation processes, information on this subject is still scarce and poorly understood. For that reason, the present review paper intends to assemble and discuss the main findings reported in the literature to date, and aims to stimulate interest and encourage further developments in this field.

Emulsion-based systems for fabrication of electrospun nanofibers: food, pharmaceutical and biomedical applications

Electrospinning is considered a promising technology for fabricating ultrafine fibers via the application of electrostatic repulsive forces. Electrospun nanofibers produced via emulsion electrospinning are widely used as delivery systems to encapsulate bioactive compounds and drugs in food and pharmaceuticals, respectively. Emulsion electrospinning has also gained significant interest for the production of vehicles for sustained and controlled release. There are several parameters affecting the properties of fabricated fibers including the type of emulsion, emulsion composition, electric field strength, conductivity of solution, surface tension, electrode configuration, solution cooling time, dissolution temperature, and solution flow rate; therefore, all these parameters should be precisely controlled to obtain optimum results. Some of the advantages of these fibers are the protection of encapsulated materials from environmental conditions, room temperature processes, release rate control and high loading efficiency. This study presents an overview of the emulsion electrospinning method, its mechanism of action and its applications in both the food and pharmaceutical fields.

Recent advances in γ-aminobutyric acid (GABA) properties in pulses: an overview

Beans, peas, and lentils are all types of pulses that are extensively used as foods around the world due to their beneficial effects on human health including their low glycaemic index, cholesterol lowering effects, ability to decrease the risk of heart diseases and their protective effects against some cancers. These health benefits are a result of their components such as bioactive proteins, dietary fibre, slowly digested starches, minerals and vitamins, and bioactive compounds. Among these bioactive compounds, γ-aminobutyric acid (GABA), a non-proteinogenic amino acid with numerous reported health benefits (e.g. anti-diabetic and hypotensive effects, depression and anxiety reduction) is of particular interest. GABA is primarily synthesised in plant tissues by the decarboxylation of l-glutamic acid in the presence of glutamate decarboxylase (GAD). It is widely reported that during various processes including enzymatic treatment, gaseous treatment (e.g. with carbon dioxide), and fermentation (with lactic acid bacteria), GABA content increases in the plant matrix. The objective of this review paper is to highlight the current state of knowledge on the occurrence of GABA in pulses with special focus on mechanisms by which GABA levels are increased and the analytical extraction and estimation methods for this bioactive phytochemical.

The effects of food essential oils on cardiovascular diseases: A review

ABSTRACT Essential oils (EO) are complex secondary metabolites, which are produced by aromatic plants and identified by their powerful odors. Present studies on EO and their isolated ingredients have drawn the attention of researchers to screen these natural products and evaluate their effect on the cardiovascular system. Some EO, and their active ingredients, have been reported to improve the cardiovascular system significantly by affecting vaso-relaxation, and decreasing the heart rate and exert a hypotension activity. Several mechanisms have been proposed for the role of EO and their main active components in promoting the health of the cardiovascular system. The objective of this review is to highlight the current state of knowledge on the functional role of EO extracted from plants for reducing the risk of cardiovascular diseases and their mechanisms of action. Research on EO has the potential to identify new bioactive compounds and formulate new functional products for the treatment of cardiovascular diseases such as arterial hypertension, angina pectoris, heart failure, and myocardial infarction.

Chapter 4 – Mechanisms of Microbial Inactivation by Emerging Technologies

Abstract Conventional thermal processing methods (pasteurization and sterilization) lead to degradation of the most thermolabile compounds of a food product, and they are usually energy consumers. Alternative technologies for microbial inactivation, also known as emerging technologies (e.g., pulsed electric fields, high pressure processing, ultrasounds, pulsed light, microwave and radiofrequency radiations), have been proposed since several decades as promising technologies to replace the conventional ones. Although efficient in most of the cases, either applied alone or combined with other parameters such as temperature, their mechanisms of action are still not fully understood, and numerous suggestions and demonstrations have been proposed. Here we describe briefly some emerging technologies and their mechanism of action for microbial inactivation.

Recent advances in the application of microbial transglutaminase crosslinking in cheese and ice cream products: A review

Microbial transglutaminase (MTGase) has been currently utilized to form new food structures and matrices with high physicochemical stability. Incorporation of this multi-functional enzyme into structural composition of milk protein-based products, such as cheese and ice cream, can not only be a successful strategy to improve their nutritional and technological characteristics through intramolecular cross-linking, but also to reduce the production cost by decreasing fat and stabilizer contents. The recent research developments and promising results of MTGase application in producing functional formulations of cheese and ice cream with higher quality characteristics are reviewed. New interesting insights and future perspectives are also presented. The addition of MTGase to cheese led to significant improvements in moisture, yield, texture, rheology and sensory properties, without changes in the chemical composition. Furthermore, pH value of ice cream is not affected by the MTGase treatment. Compared to untreated ice creams, application of MTGase significantly promotes consistency, fat destabilization, overrun and organoleptic acceptance, while a substantial reduction in firmness and melting rate of samples was observed. The addition of MTGase to cheese and ice cream-milk provides reinforcement to the protein matrix and can be considered as a novel additive for improving the physicochemical and organoleptic properties of final products.

Innovative technologies for the recovery of phytochemicals from Stevia rebaudiana Bertoni leaves: A review

Stevia rebaudiana Bertoni has gained increased industrial and scientific interests in the last 20 years, representing a suitable nutritional alternative to sucrose and artificial sweeteners. Moreover, this plant contains polyphenols, chlorophylls, and carotenoids that may be extracted for production of nutraceuticals and functional foods. Because of nutritional and technological advantages over sucrose, innovative approaches for the extraction of highly valued compounds from Stevia leaves have been developed and optimized. In contrast to conventional alternatives, innovative extraction methods allow higher yields in a shorter time, less usage of organic solvents, and reduced energy consumption. In this paper, the use of innovative extraction techniques: MAE, UAE, HPAE, PLE, SFE, PEF, HVED, cold plasma, and RSLDE for the recovery of non-nutrients with putative health benefits from Stevia leaves is discussed.

Energy saving food processing

Abstract One of the challenges to increase the profitability in the food industry is to reduce the consumption of energy. Energy is mainly consumed by either increasing or decreasing the temperature during the different processes. A known strategy to recover a part of the consumed energy is to regenerate heat during products cooling, to preheat the untreated products. To improve energy saving efficiency, many other techniques have been proposed either in the literature or already implemented in the processing chain of food products. These techniques, applied either alone or combined with existing ones, include electrotechnologies (i.e., pulsed electric fields), microwaves, ultrasounds, pulsed light processing, high-pressure processing, and some other technologies that are discussed herein. With regard to the diversity of unit operations in the food industry, this chapter mainly deals with analyzing the energy saving using these novel technologies in pasteurization and sterilization, extraction, evaporation and dehydration, and chilling and freezing. The mechanisms of action of the described technologies as well as their advantages and disadvantages are discussed.