Kumar Mallikarjunan

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 20u202fyears, 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.

An overview of organosulfur compounds from Allium spp.: From processing and preservation to evaluation of their bioavailability, antimicrobial, and anti-inflammatory properties

The use of Allium species and their extracts has been known since immemorial times due to their health beneficial properties. It is known that functional properties of Allium genus come from the high content of bioactive compounds. The biological activity of Allium extracts will be conditioned by the type of Allium variety, agricultural conditions, and specific extraction process used since all these factors affect the content and the profile of bioactive compounds. Innovative extraction techniques in comparison to conventional processes could be considered as a promising tool to recover bioactive compounds from Allium spp. with antimicrobial and anti-inflammatory properties. Trying to fill the gap in the literature, this paper reviews the chemical composition, the effects of processing on the nutritional and bioactive composition of Allium species and their extracts. Moreover, the antimicrobial and anti-inflammatory effects, as well as the bioavailability of bioactive compounds of edible members from the Allium genus is discussed.

Application of plant extracts to improve the shelf-life, nutritional and health-related properties of ready-to-eat meat products

Plant extracts are increasingly becoming important additives in food industry due to their antimicrobial and antioxidant abilities that delay the development of off-flavors and improve the color stability in ready-to-eat (RTE) meat products. Due to their natural origin, they are excellent candidates to replace synthetic molecules, which are generally considered to have toxicological and carcinogenic effects. The efficient extraction of these antioxidant molecules from their natural sources, along with the determination of their activity in the commercialized products, have been a great challenge for researchers and food chain contributors. The objective of this review is to highlight the application of plant extracts to improve the shelf-life, nutritional and health-related properties of RTE meat products. The sensory effects of these extracts on RTE meat products as well as the possible synergistic effects of a combination of extracts are discussed.

Effect of pre-treatments on the antioxidant potential of phenolic extracts from barley malt rootlets

In this study, barley malt rootlets (BMR) were subjected to five different pre-treatments (steaming (220u202f°C), roasting (60u202f°C), autoclaving (121u202f°C), microwaving (160-800u202fW, 30-120u202fs) and enzyme treatment). Total phenolic content (TPC) and antioxidant activity of the BMR extracts were evaluated for both free and bound phenolics. The free phenolic content for non-treated extract was 1.8u202fmg/g of dry weight of BMR with 17.5% of antioxidant activity. Among the pre-treatments, autoclaving exhibited the highest values for free phenolics of 3.8u202fmg/g of dry weight of BMR and 71.6% of antioxidant activity. Pre-treatments did not show any effect on bound phenolic content, but increased antioxidant activity. The highest %DPPH activity for bound phenolics was observed for microwave treatment (160u202fW, 120u202fs) with 49.9%. Overall, pre-treatments significantly increased the free phenolic content of BMR phenolic extracts. Additional research is necessary to understand the phenolic profile and the thermal interactions of bound phenolic extracts.

Effect of Emerging Processing Technologies on Maillard Reactions

Thermal treatment is one of the main unit operations applied to improve the microbiological quality of food products. It utilizes the lethal effects of heat against thermosensitive microorganisms, both pathogens and spoilage organisms; however, at the same time it induces degradation of the organoleptic and nutritional properties of foods due to non-enzymatic Maillard reactions. These reactions occur between amino compounds and reducing sugars, and are intensified with the increase of temperature. Some research studies have investigated the potential use of emerging technologies such as pulsed electric fields, ohmic heating and high hydrostatic pressure to reduce the occurrence of non-enzymatic browning in foods during processing. Despite the numerous advantages of emerging technologies over conventional ones, their impact on Maillard reactions is complex and not well understood with both positive and negative impacts. This chapter reviews the impact of emerging technologies on Maillard reactions in foods.

Gamma-Aminobutyric Acid

Gamma-aminobutyric acid (GABA) is a non-protein amino acid, which has received extensive attention over the past decades due to its various physiological implications in plants, animals, and microorganisms. It has anti-diabetic and hypotensive effects, depression and anxiety reduction properties in addition to many other health-related benefits. Recent efforts have been focused on amplifying GABA production using different chemical processes from various bio-based or non-chemical precursors. In this chapter, the chemical synthesis of GABA from γ-butyrolactone (GBL), γ-halobutyronitrile, 2-bromopropanoic acid, and glutaric anhydride will be highlighted. Moreover, the production of GABA by plants and microorganisms as well as the extraction, purification methods and potential health benefits will be discussed.