Nutritional Composition of Processed Onion: S-Alk(en)yl-l-cysteine Sulfoxides, Organic Acids, Sugars, Minerals, and Vitamin C

New Natural and Sustainable Cosmetic Preservative Based on Sugarcane Straw Extract

Preservative ingredients in cosmetic formulations undertake a necessary role in the prevention of microbial contamination. In this field, there is an unmet need for natural, sustainable, and effective preservatives. Thus, the main goal of this work was to evaluate a sugarcane straw extract-based ingredient and investigate its potential as a preservative for cosmetic applications. Different ingredients were developed using several cosmetic solvents to improve the solubility of the extracted compounds. The antimicrobial activity was assessed against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The 1,2-hexanediol was the solvent that allowed us to achieve the ingredient (20% dry extract dispersed in 25% 1,2-hexanediol in water) with the best antimicrobial performance, showing a minimum inhibitory concentration of between 5% and 3% (I). The 5% (w/v) concentration of this ingredient complied with the USP51 standards for cosmetic preservatives. Real-time (25 °C, 65% RH) and accelerated stability (40 °C, 75% RH) tests were conducted to determine the ingredient stability, and it was found that one month of storage time at room temperature would be ideal for better ingredient stability and performance in terms of composition, pH, color, and antioxidant activity.

Farm to Fork Stability of Phytochemicals and Micronutrients in Brassica oleracea and Allium Vegetables

Brassica oleracea and Allium vegetables are known for their unique, family specific, water-soluble phytochemicals, glucosinolates, and S-alk(en)yl-l-cysteine sulfoxides, respectively. However, they are also important delivery systems of several other health-related compounds, such as carotenoids (lipid-soluble phytochemicals), vitamin C (water-soluble micronutrient), and vitamin K1 (lipid-soluble micronutrient). When all-year-round availability or transport over long distances is targeted for these often seasonal, locally grown vegetables, processing becomes indispensable. However, the vegetable processing chain, which consists of multiple steps (e.g., pretreatment, preservation, storage, preparation), can impact the nutritional quality of these vegetables corresponding to the nature of the health-related compounds and their susceptibility to (bio)chemical conversions. Since information about the impact of the vegetable processing chain is scattered per compound or processing step, this review targets an integration of the state of the art and discusses needs for future research. Starting with a discussion on substrate-enzyme location within the vegetable matrix, an overview is provided of the impact and potential of processing, encompassing a wide range of (nonenzymatic) conversions.

Vitamin C fortification: need and recent trends in encapsulation technologies

The multifaceted role of vitamin C in human health intrudes several biochemical functions that are but not limited to antioxidant activity, homoeostasis, amino acid synthesis, collagen synthesis, osteogenesis, neurotransmitter production and several yet to be explored functions. In absence of an innate biosynthetic pathway, humans are obligated to attain vitamin C from dietary sources to maintain its optimal serum level (28 μmol/L). However, a significant amount of naturally occurring vitamin C may deteriorate due to food processing, storage and distribution before reaching to the human gastrointestinal tract, thus limiting or mitigating its disease combating activity. Literature acknowledges the growing prevalence of vitamin C deficiency across the globe irrespective of geographic, economic and population variations. Several tools have been tested to address vitamin C deficiency, which are primarily diet diversification, biofortification, supplementation and food fortification. These strategies inherit their own advantages and limitations. Opportunely, nanotechnology promises an array of delivery systems providing encapsulation, protection and delivery of susceptible compounds against environmental factors. Lack of clear understanding of the suitability of the delivery system for vitamin C encapsulation and fortification; growing prevalence of its deficiency, it is a need of the hour to develop and design vitamin C fortified food ensuring homogeneous distribution, improved stability and enhanced bioavailability. This article is intended to review the importance of vitamin C in human health, its recommended daily allowance, its dietary sources, factors donating to its stability and degradation. The emphasis also given to review the strategies adopted to address vitamin c deficiency, delivery systems adopted for vitamin C encapsulation and fortification.

S-Allyl cysteine in garlic (Allium sativum): Formation, biofunction, and resistance to food processing for value-added product development

S-allyl cysteine (SAC), which is the most abundant bioactive compound in black garlic (BG; Allium sativum), has been shown to have antioxidant, anti-apoptotic, anti-inflammatory, anti-obesity, cardioprotective, neuroprotective, and hepatoprotective activities. Sulfur compounds are the most distinctive bioactive elements in garlic. Previous studies have provided evidence that the concentration of SAC in fresh garlic is in the range of 19.0-1736.3 μg/g. Meanwhile, for processed garlic, such as frozen and thawed garlic, pickled garlic, fermented garlic extract, and BG, the SAC content increased to up to 8021.2 μg/g. BG is an SAC-containing product, with heat treatment being used in nearly all methods of BG production. Therefore, strategies to increase the SAC level in garlic are of great interest; however, further knowledge is required about the effect of processing factors and mechanistic changes. This review explains the formation of SAC in garlic, introduces its biological effects, and summarizes the recent advances in processing methods that can affect SAC levels in garlic, including heat treatment, enzymatic treatment, freezing, fermentation, ultrasonic treatment, and high hydrostatic pressure. Thus, the aim of this review was to summarize the outcomes of treatment aimed at maintaining or increasing SAC levels in BG. Therefore, publications from scientific databases in this field of study were examined. The effects of processing methods on SAC compounds were evaluated on the basis of the SAC content. This review provides information on the processing approaches that can assist food manufacturers in the development of value-added garlic products.

Effects of High Hydrostatic Pressure Combined with Vacuum-Freeze Drying on the Aroma-Active Compounds in Blended Pumpkin, Mango, and Jujube Juice

A combination process of completely non-thermal processing methods involving high hydrostatic pressure (HHP) and vacuum-freeze drying (VFD) for producing a new snack from fruit and vegetable blends was developed, and the effect of the process on flavor quality was investigated. The HHP-VFD treatment did not significantly reduce volatile compound contents compared to single HHP or VFD. Gas chromatography-olfactometry showed that HHP-VFD raised the contents of floral-like volatile compounds (e.g., β-ionone) compared to the untreated sample. Sensory evaluation analysis confirmed that the overall liking was unchanged after the HHP-VFD treatment. The HHP-VFD combined treatment is effective in maintaining the flavor and extending shelf life, and is convenient for the portability and transportation of ready-to-drink juice.

Impact of High-Pressure Processed Onion on Colonic Metabolism Using a Dynamic Gastrointestinal Digestion Simulator

Onions are the main dietary source of flavonols that have been associated with important health-promoting properties. Onion treated by high-pressure processing (HPP-treated onion) was subjected to a dynamic gastrointestinal digestion and colon fermentation simulator (DGID-CF) to study the effect on the gut microbiota metabolism in the three colon regions (ascending—AC, transverse—TC, and descending—DC) by means of chronic feeding with 27 g/day for 14 days. HPP-treated onion presented a high content of the flavonols quercetin-3,4’-diglucoside and quercetin-4’-glucoside, and a large percentage of them reached the AC without change. TC and DC progressively increased the total phenolic metabolites 2.5 times respective to day 2, mainly 3-hydroxyphenylacetic, 4-hydroxyphenylacetic, 3-(4-hydroxyphenyl)-propionic, and 3,4-dihydroxyphenylpropionic acids. In addition, the chronic feeding increased the beneficial colon bacteria Bifidobacterium spp. and Lactobacillus spp. and the production of total SCFAs (acetic, propionic, and butyric acids) 9 times (AC), 2.2 times (TC), and 4.4 times (DC) respective to day 1. A multivariate analysis (principal component analysis, PCA) showed a clear separation between the three colon regions based on their phenolic composition (precursors and metabolites). These results showed that HPP-treated onion modulated the human gut microbiota’s metabolism and the DGID-CF is a good system to study these changes.

Applicability of Pulsed Electric Field (PEF) Pre-Treatment for a Convective Two-Step Drying Process

Available literature and previous studies focus on the Pulsed Electric Field (PEF) parameters influencing the drying process of fruit and vegetable tissue. This study investigates the applicability of PEF pre-treatment considering the industrial-scale drying conditions of onions and related quality parameters of the final product. First, the influence of the PEF treatment (W = 4.0 kJ/kg, E = 1.07 kV/cm) on the convective drying was investigated for samples dried at constant temperatures (65, 75, and 85 °C) and drying profiles (85/55, 85/65, and 85/75 °C). These trials were performed along with the determination of the breakpoint to assure an industrial drying profile with varying temperatures. A reduction in drying time of 32% was achieved by applying PEF prior to drying at profile 85/65 °C (target moisture ≤7%). The effective water diffusion coefficient for the last drying section has been increased from 1.99 × 10-10 m2/s to 3.48 × 10-10 m2/s in the PEF-treated tissue. In case of the 85/65 °C drying profile, the PEF-treated sample showed the highest benefits in terms of process efficiency and quality compared to the untreated sample. A quality analysis was performed considering the colour, amount of blisters, pyruvic acid content, and the rehydration behavior comparing the untreated and PEF-treated sample. The PEF-treated sample showed practically no blisters and a 14.5% higher pyruvic acid content. Moreover, the rehydration coefficient was 47% higher when applying PEF prior to drying.

The effect of drying temperature on bioactive compounds and antioxidant activity of Leccinum scabrum (Bull.) Gray and Hericium erinaceus (Bull.) Pers

In the study the effect of drying temperature on phenolic and organic acid content, total phenolic content, ergosterol content, antioxidant activity and content of 40 elements in fruiting bodies of Leccinum scabrum and Hericium erinaceus was estimated. The analysis was performed for fresh fruiting bodies and those dried at 20, 40 and 70 °C. Drying resulted in changes in the profile of phenolic and organic acids. Drying generally resulted in losses of the content of total phenolics, ergosterol and antioxidant activity in both species. However, a reduction and an increase of phenolic acids and organic acids were observed. The greatest reduction of the compounds was generally observed at 70 °C. The greatest losses concerned organic acids (some single components and total) (even more than 90% of some compounds). The inhibition of free radicals decreased in the following order: fresh samples > air-dried samples > samples dried at 40 °C > samples dried at 70 °C. The drying temperature affected only selected element contents in fruiting bodies.

Novel Food Processing and Extraction Technologies of High-Added Value Compounds from Plant Materials

Some functional foods contain biologically active compounds (BAC) that can be derived from various biological sources (fruits, vegetables, medicinal plants, wastes, and by-products). Global food markets demand foods from plant materials that are “safe”, “fresh”, “natural”, and with “nutritional value” while processed in sustainable ways. Functional foods commonly incorporate some plant extract(s) rich with BACs produced by conventional extraction. This approach implies negative thermal influences on extraction yield and quality with a large expenditure of organic solvents and energy. On the other hand, sustainable extractions, such as microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), high-pressure assisted extraction (HPAE), high voltage electric discharges assisted extraction (HVED), pulsed electric fields assisted extraction (PEF), supercritical fluids extraction (SFE), and others are aligned with the “green” concepts and able to provide raw materials on industrial scale with optimal expenditure of energy and chemicals. This review provides an overview of relevant innovative food processing and extraction technologies applied to various plant matrices as raw materials for functional foods production.

Fresh-Cut Onion: A Review on Processing, Health Benefits, and Shelf-Life

The ready-to-eat produce market has grown rapidly because of the health benefits and convenience associated with these products. Onion is widely used as an ingredient in an extensive range of recipes from breakfast to dinner and in nearly every ethnic cuisine. However, cutting/chopping of onion is a nuisance to many consumers due to the lachrymatory properties of the volatiles generated that bring tears to eyes and leave a distinct odor on hands. As a result, there is now an increasing demand for fresh-cut, value-added, and ready-to-eat onion in households, as well as large-scale uses in retail, food service, and various food industries, mainly due to the end-use convenience. Despite these benefits, fresh-cut onion products present considerable challenges due to tissue damage, resulting in chemical and physiological reactions that limit product shelf-life. Intensive discoloration, microbial growth, softening, and off-odor are the typical deteriorations that need to be controlled through the application of suitable preservation methods. This article reviews the literature related to the fresh-cut onion, focusing on its constituents, nutritional and health benefits, production methods, quality changes throughout storage, and technologies available to increase product shelf-life.

Chemical Composition and Antioxidant Properties of Five White Onion (Allium cepaL.) Landraces

Five onion landraces belonging toBianca di Pompeicv., cultivated in Campania region (Italy), were characterized for their main quality parameters. The onion landraces were harvested at the end of the growth cycle corresponding to the ripening time and harvest month, respectively: February, March, April, May, and June. The total content of volatile compounds as well as the sulfur-containing compounds inAprilaticawas significantly (p≤0.05) higher than the other landraces investigated. The nutraceutical feature investigated through the total phenols, phenols profile, and antioxidant activity showed higher values for the samples harvested in spring months. High pungency values ranging from 9 to 14 μmol/g FW were found in all onion landraces investigated as enzymatically (alliinase) produced pyruvate (EPY). The organic acids profile (malic, citric, succinic, pyruvic, oxalic, ascorbic, and tartaric acids) highlighted malic and citric acids in higher amounts in all landraces. Fructose, glucose, and sucrose were found as soluble sugars and fructose was the most abundant. Generally, the results highlighted the growth temperature influence on the investigated quality parameters.

Economical and environmentally-friendly approaches for usage of onion (Allium cepa L.) waste

General anatomy and different layers in onion.

High-cholesterol diet enriched with onion affects endothelium-dependent relaxation and NADPH oxidase activity in mesenteric microvessels from Wistar rats

BACKGROUND

The aim of the present study was to examine the effects of onion as functional ingredient on the oxidative status, lipoprotein levels (total cholesterol-TC, HDL-C, LDL-C), triacylglycerides (TAG) and vascular reactivity of mesenteric arteries in hypercholesterolemic Wistar rats.

METHODS

Twenty-four animals were fed with three different diets [control, high-cholesterol diet (HC) and high-cholesterol enriched with onion diet (HCO)]. After seven weeks of experimental feeding the rats were euthanized for blood and tissues collection. TC, HDL-C, LDL-C and TAG were measured, and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(•+)) scavenging capacity and ferric reducing antioxidant power (FRAP) were determined in plasma. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were assayed in erythrocyte lysates. Endothelium-dependent vasodilation to acetylcholine was evaluated in mesenteric arterial segments. NADPH oxidase (NOX) was also measured by lucigenin-derived chemiluminiscence.

RESULTS

The dietary cholesterol content significantly affected plasma lipoprotein levels, increased superoxide generation from NOX, and caused impaired endothelium-dependent vasodilation in the rat mesenteric arteries. Onion ingredient improved antioxidant status in HCO group, as it was evidenced by ABTS(•+) and FRAP values and SOD and GPx enzyme activities compared to the HC-fed group, reduced the increment in NOX activity and reversed endothelial dysfunction promoted by the HC diet. Scavenging of superoxide with TEMPOL or inhibition of NOX with apocynin improved endothelium-dependent vasodilation only in HC-fed rats.

CONCLUSIONS

Enrichment of diet with onion as functional ingredient could be proposed as a complementary approach to prevent or partially modulate vascular dysfunction, reducing some of the risk indexes linked to initial development of atherosclerosis.

Effect of processing conditions on the organosulfides of shallot (Allium cepa L. Aggregatum group)

There is a growing account of the health benefits of H2S as an endogenous cell-signaling molecule. H2S from organic polysulfides, in particular, is increasingly gaining attention for their beneficial effects to cardiovascular health. Here, we studied shallot as a potential dietary source of organic polysulfides and examined the effects of processing conditions on its polysulfide profiles. Boiling, autoclaving, and freeze-drying were tested on whole and crushed shallot bulbs, analyzing their effect on the yield of organosulfides. Seventeen organosulfides, including disulfides, trisulfides, and cyclic polysulfides, were identified. Significant differences in the quantitative and qualitative profiles of organosulfides in the hydrodistilled and solvent extracted oils were observed. Freeze-drying retained the majority of the organosulfides, but the whole-autoclaved and whole-boiled shallots lost more than 95% of their organic polysulfides. Crushed-boiled and crushed-autoclaved shallot lost 76-80% of their organosulfides, likely due to the thermal sensitivity of these compounds. The organosulfide profiles are sensitive to the pH values of the processing media. In general, disulfides increased at basic pH (pH 9.0) while trisulfides and cyclic organosulfides are much higher at the acidic to neutral pH values (pH 3.0-5.0). Our results provide important information on the effects of processing conditions that are relevant for optimizing extraction of organosulfides from shallot for further studies evaluating their H2S-releasing activity.