Impact of Innovative Technologies on the Content of Vitamin C and Its Bioavailability from Processed Fruit and Vegetable Products

Comparison of different drying technologies for kiwifruit pomace: Changes in physical characteristics, nutritional properties and antioxidant capacities

The objective of this study was to evaluate the impacts of different drying technologies including microwave drying (MD), vacuum microwave drying (VMD), sun drying (SD), vacuum drying (VD), hot air drying (HAD), and vacuum freeze drying (VFD) on the physical characteristics, nutritional properties and antioxidant capacities of kiwifruit pomace in order to realize by-product utilization and improve energy efficiency. Results showed that both MD and VMD significantly reduced drying time by >94.6%, compared to traditional thermal drying which took 14-48 h. MD exhibited the highest content of soluble dietary fiber (9.5%) and the lowest energy consumption. Furthermore, VMD resulted in the highest content of vitamin C (198.78 mg/100 g) and reducing sugar (73.78%), and the antioxidant capacities ranked only second to VFD. Given the financial advantages and product quality, VMD was suggested to be advantageous technology in actual industrial production.

Iodine enriched kale (Brassica oleracea var. sabellica L.)-The influence of heat treatments on its iodine content, basic composition and antioxidative properties

Iodine deficiency in the diet globally continues to be a cause of many diseases and disabilities. Kale is a vegetable that has health-promoting potential because of many nutrients and bioactive compounds (ascorbic acid, carotenoids, glucosinolates and phenolic compounds). Brassica vegetables, including kale, have been strongly recommended as dietary adjuvants for improving health. The nutrient and health-promoting compounds in kale are significantly affected by thermal treatments. Changes in phytochemicals upon such activities may result from two contrary phenomena: breakdown of nutrients and bioactive compounds and a matrix softening effect, which increases the extractability of phytochemicals, which may be especially significant in the case of iodine-fortified kale. This study investigated changes of basic composition, iodine, vitamin C, total carotenoids and polyphenols contents as well as antioxidant activity caused by steaming, blanching and boiling processes in the levels of two cultivars of kale (green and red) non-biofortified and biofortified via the application to nutrient solutions in hydroponic of two iodoquinolines [8-hydroxy-7-iodo-5-quinolinesulfonic acid (8-OH-7-I-5QSA) and 5-chloro-7-iodo-8-quinoline (5-Cl-7-I-8-Q)] and KIO3. Thermal processes generally significantly reduced the content of the components in question and the antioxidant activity of kale, regardless of cultivar and enrichment. It was observed that the red cultivar of kale had a greater ability to accumulate and reduce iodine losses during the culinary processes. 8-hydroxy-7-iodo-5-quinolinesulfonic acid showed a protective effect against the treatments used, compared to other enrichments, thus contributing to the preservation of high iodine content.

Enzymatic treatment to improve permeability and quality of cherry tomatoes for production of dried products

BACKGROUND

Cherry tomatoes are nutritious and favored by consumers. Processing them into dried cherry tomatoes can prolong their storage life and improve their flavor. The pretreatment of tomato pericarp is crucial for the subsequent processing. However, the traditional physical and chemical treatments of tomato pericarp generally cause nutrient loss and environmental pollution.

RESULTS

In this study, a novel enzymatic method for cherry tomatoes was performed using mixed enzymes containing cutinase, cellulase and pectinase. Results showed that the pericarp permeability of cherry tomatoes was effectively improved due to enzymatic treatment. Changes in the microscopic structure and composition of the cuticle were revealed. After treatment with different concentrations of enzymes, cherry tomatoes exhibited higher pericarp permeability and sensory quality to varying degrees. The lycopene content and total polyphenol content significantly increased 2.4- and 1.45-fold, respectively. In addition, the satisfactory effect of the six-time reuse of enzymes on cherry tomatoes could still reach the same level as the initial effect, which effectively reduced the cost of production.

CONCLUSIONS

This study revealed for the first time that a mixed enzymatic treatment consisting of cutinase, pectinase and cellulase could effectively degrade the cuticle, enhance the pericarp permeability and improve the quality of cherry tomatoes, with the advantages of being mildly controllable and environmentally friendly, providing a new strategy for the processing of dried cherry tomatoes. © 2023 Society of Chemical Industry.

Effects of Thermosonication on the Antioxidant Capacity and Physicochemical, Bioactive, Microbiological, and Sensory Qualities of Blackcurrant Juice

This study investigated the effects of thermosonication (TS) on the quality of blackcurrant juice, along with its physicochemical properties, bioactive compounds, antioxidant capacity, and microbiological and sensory qualities. The treatments included raw juice (RJ), pasteurized juice (90 °C, 1 min, PJ), and thermosonicated juice (480 W, 40 kHz at 40, 50, or 60 °C, for 10, 20, 30, or 40 min, TJ). The results indicated that the effects of pasteurization and thermosonication on the pH, total soluble solids, and titratable acidity of the juice were not significant (p > 0.05). However, the cloudiness, browning index, and viscosity were significantly increased (p < 0.05), and the color properties of the blackcurrant juice were improved. The total phenolic, flavonoid, and anthocyanin contents of TJ (treated at 50 °C for 30 min) were increased by 12.6%, 20.9%, and 40.4%, respectively, and there was a notable decline in ascorbic acid content after the pasteurization treatment, while the loss was minor in all TJ samples compared with RJ. The scavenging ability of 1,1-diphenyl-2-pyridyl and hydroxyl radicals increased to 52.77% and 50.52%, respectively, which were significantly (p < 0.05) higher than those in the RJ and PJ samples. In addition, both pasteurization and thermosonication resulted in a significant (p < 0.05) reduction in microbial counts, while there were no significant (p > 0.05) differences in the sensory parameters compared with the RJ samples. In conclusion, this study suggests that TS is an effective method that can be used as an alternative to pasteurization to improve the quality of blackcurrant juice.

Impact of sulfite use and acidification on chemical quality components in thermally processed watermelon juices

The present study compared pasteurized and reconstituted (from vacuum-concentrated) watermelon juices with sulfite use (∼40 mg/L) and acidification (pH = 4.2) to fresh watermelon juices. The products were evaluated for phenolics, free amino acids, carotenoids, sugars, organic acids, and alcohols by high-performance liquid chromatography-HPLC and the volatile profile by headspace-gas chromatography/mass spectrometry(HS-GC/MS). Pasteurization had no significant impact on most of the chemical components. Furthermore, it potentiated typical watermelon aromas (E,E)-2,6-nonadienal, (Z)-3-nonen-1-ol, 4-hexen-1-ol, (E,Z)-3,6-nonadien-1-ol, 6-amino-2-methyl-2-heptanol, (E)-6-nonenal, (E)-2-nonenal, pentanal, nonanal and 1-nonanol), without off-flavor compounds formation. On the other hand, the reconstituted juice showed reduced amino acids (serine, glutamine, and tryptophan), phenolics (epicatechin gallate, myricetin, and cis-resveratrol), carotenoids (lycopene, β-carotene, and violaxanthin) and most volatile compounds. Our results showed that sulfite and acidification could maintain watermelon juice's nutritional and quality parameters after pasteurization. The vacuum concentration and reconstitution processes negatively impacted the evaluated compounds. Our findings contribute to improving thermal processes in watermelon juices for better preservation of nutrients, flavor, and bioactive compounds.

Trends and challenges of fruit by-products utilization: insights into safety, sensory, and benefits of the use for the development of innovative healthy food: a review

A significant portion of the human diet is comprised of fruits, which are consumed globally either raw or after being processed. A huge amount of waste and by-products such as skins, seeds, cores, rags, rinds, pomace, etc. are being generated in our homes and agro-processing industries every day. According to previous statistics, nearly half of the fruits are lost or discarded during the entire processing chain. The concern arises when those wastes and by-products damage the environment and simultaneously cause economic losses. There is a lot of potential in these by-products for reuse in a variety of applications, including the isolation of valuable bioactive ingredients and their application in developing healthy and functional foods. The development of novel techniques for the transformation of these materials into marketable commodities may offer a workable solution to this waste issue while also promoting sustainable economic growth from the bio-economic viewpoint. This approach can manage waste as well as add value to enterprises. The goal of this study is twofold based on this scenario. The first is to present a brief overview of the most significant bioactive substances found in those by-products. The second is to review the current status of their valorization including the trends and techniques, safety assessments, sensory attributes, and challenges. Moreover, specific attention is drawn to the future perspective, and some solutions are discussed in this report.

Application of thermosonication for guava juice processing: Impacts on bioactive, microbial, enzymatic and quality attributes

The present work explores different conditions of thermosonication (TS) processing that would ensure microbiological and enzymatic safety for guava juice while simultaneously maximizing the preservation of its quality attributes. The guava juice was subjected to TS treatment (frequency: 40 kHz; power: 200 W; Temperature: 40, 60, and 80 °C; Time: 2, 6 and 10 min) and was compared with fresh and pasteurized (90 °C/60 s) juice samples. The objectives of the research work were to determine the effect of thermosonication on the quality attributes such as total soluble solids (TSS), pH, titratable acidity, cloud value, color attributes, total phenolic contents, total flavonoid contents, antioxidant activity, ascorbic acid levels, enzymatic, microbiological, and sensory properties. The thermosonicated and pasteurized samples showed no significant (p > 0.05) changes in pH, total soluble solids, and titratable acidity. TS improved the cloud value and color attributes. Furthermore, TS enhanced total phenols (10 to17%), flavonoids (5 to 25%), antioxidant activity (10.45% to 14.55%) and retention of ascorbic acid (61.98-83.32%) relative to control. Thermosonicated sample at 80 °C/10 min gives the maximum inactivation of Pectin methyl esterase (PME), Peroxidase (POD) and Polyphenol oxidase (PPO) enzymes. While both thermosonication and pasteurization drastically decreased the microbial count to undetectable levels, only TS exhibited modest improvement in sensory qualities. The results demonstrated that TS can enhance the overall safety, quality, and commercial viability of guava juice as a practical substitute to pasteurization.

Oxidative stress, the blood-brain barrier and neurodegenerative diseases: The critical beneficial role of dietary antioxidants

In recent years, growing awareness of the role of oxidative stress in brain health has prompted antioxidants, especially dietary antioxidants, to receive growing attention as possible treatments strategies for patients with neurodegenerative diseases (NDs). The most widely studied dietary antioxidants include active substances such as vitamins, carotenoids, flavonoids and polyphenols. Dietary antioxidants are found in usually consumed foods such as fresh fruits, vegetables, nuts and oils and are gaining popularity due to recently growing awareness of their potential for preventive and protective agents against NDs, as well as their abundant natural sources, generally non-toxic nature, and ease of long-term consumption. This review article examines the role of oxidative stress in the development of NDs, explores the 'two-sidedness' of the blood-brain barrier (BBB) as a protective barrier to the nervous system and an impeding barrier to the use of antioxidants as drug medicinal products and/or dietary antioxidants supplements for prevention and therapy and reviews the BBB permeability of common dietary antioxidant suplements and their potential efficacy in the prevention and treatment of NDs. Finally, current challenges and future directions for the prevention and treatment of NDs using dietary antioxidants are discussed, and useful information on the prevention and treatment of NDs is provided.

Changes in the Fruit Quality Parameters of Medlar Fruit (Mespilus germanica L.) after Heat Treatment, Storage, Freezing or Hoarfrost

The present study deals with the comparison of traditional fruit processing methods on medlar fruits and their effects on sugar content, organic acids, and phenolic composition in the medlar fruit variety 'Domača nešplja'. The study aimed to analyze which processing methods can be used to make technologically mature medlar fruits that are not yet suitable for consumption edible and to maintain their good chemical quality. The two major sugars in medlars are fructose (59.30 g/kg FW) and glucose (54.43 g/kg FW), and the most abundant organic acids present are malic (8.44 g/kg FW) and quinic acid (8.77 g/kg FW). A total of 38 different phenolic compounds were identified in the medlar fruits: 13 phenolic acids, 9 flavanols, 1 flavone, 3 flavanones, and 12 flavonol glycosides. To explicate: phenolic acids (532.85 mg/kg FW) and flavanols (375.21 mg/kg FW) predominated; neochlorogenic acid had the highest content among phenolic acids; and procyanidins were the most abundant flavanols. The analysis observed statistical differences in metabolite content amongst fruits treated differently (technologically ripe fruits (harvested from the three fruits), edible fruits (technologically ripe fruits stored at 8 °C for 25 days), fruits exposed to the hoarfrost (temperature -1 °C to -4 °C), fruits heated at 60 °C (3 h), and frozen fruits (at -20 °C for 2 months). The lowest levels of fructose (191.77-195.1 g/kg DW) and sorbitol (29.35-31.3 g/kg DW) were detected in the heated and edible fruits. Edible fruits had a 30% lower content of organic acids than technologically ripe fruits and a five times lower content of flavanols, whereas flavonols had an 18.7 times lower content of phenolic acids than technologically ripe fruits. Heating the fruits to 60 °C resulted in a 40% increase in total phenolic compounds in medlars. The results of the study indicate that exposure of medlar fruit to hoarfrost does not significantly affect the chemical quality of the fruit and only minimally alters the composition of sugars, acids, and phenolic compounds. The processing of medlar fruit with hoarfrost, therefore, remains the most suitable method of fruit bletting.

Physicochemical properties and antioxidant activities of marula fruit (Sclerocarya birrea subsp. Caffra) steamed and boiled before juice extraction

Marula fruit is one of the most underutilized fruits in South Africa, and it has been reported to contain a high amount of vitamin C which is regarded as the cheapest antioxidant. The fruit pulp is traditionally extracted and boiled into juice, a process that adversely affects the vitamin C and bioactive phenolic profile of the resulting juice. This study evaluated the effects of boiling and steaming on the physicochemical properties of marula fruit juice. The pH, percentage yield, total titratable acidity (TTA), total soluble solids (TSS), total phenolic content (TPC), radical scavenging capacity, and vitamin C content of the fruit juice were examined. The study also investigated the total carotene, color, and sensory properties of the fruit juice. The results showed that boiling and steaming significantly decreased the Vit C content of the juice (75.67 and 60.05 mg/100 g) compared to control sample (95.11 mg/100 g). The TPC, radical scavenging capacity, and total carotene content of the fruit juice increase because the heating processes softened the matrix of the fruit increasing the extractability of the phenolics and carotene content of the samples. The color of the marula fruit juice was increased by both boiling and steaming, while the sensory properties of the marula fruit juice extracted from steamed marula fruit had the highest scores in all the measured parameters. Steaming of marula fruit before juice extraction improved the nutritional composition, antioxidant activities, and sensory properties of marula fruit juice.

Immobilization of Natural Antimicrobial Compounds on Food-Grade Supports as a New Strategy to Preserve Fruit-Derived Foods

The use of natural antimicrobials in the food industry is being proposed as an eco-friendly postharvest technology to preserve fruit-derived foods. In this context, this systematic review aims to describe and discuss the application of naturally occurring antimicrobial compounds in the processing of fruit-derived foods by the PRISMA methodology. In a first step, the use of free natural antimicrobials was investigated as an approach to identify the main families of bioactive compounds employed as food preservatives and the current limitations of this dosage form. Then, the use of immobilized antimicrobials, in an innovative dosage form, was studied by distinguishing two main applications: addition to the food matrix as preservatives or use during processing as technological aids. Having identified the different examples of the immobilization of natural antimicrobial compounds on food-grade supports, the mechanisms of immobilization were studied in detail to provide synthesis and characterization guidelines for future developments. Finally, the contribution of this new technology to decarbonization and energy efficiency of the fruit-derived processing sector and circular economy is discussed in this review.

Effects of pretreatments using plasma functionalized water, osmodehydration and their combination on hot air drying efficiency and quality of tomato (Solanum lycopersicum L.) slices

The effects of pretreatments using plasma functionalized water (PW), osmodehydration (OD), and combined plasma functionalized water and osmodehydration (PO) on the drying characteristics, physicochemical and bioactive components of tomato slices during hot air drying at an air temperature of 55 °C and velocity of 1.5 m/s were evaluated. Results revealed that PW pretreatment led to an increase in lycopene compared to fresh samples, and shortened drying time, improved ascorbic acids, TPC, TFC, acidity, rehydration, porosity and hue, but reduced TSS, compared to dried control samples, while OD resulted in lycopene degradation during pretreatment, and prolonged drying time, increased TSS, but lowered acidity, rehydration, porosity and hue, compared to dried control samples. On the other hand, PO was found to overcome the shortcomings of OD with enhancement in the lycopene during pretreatment, and showed accelerated moisture transfer, improved bioactive, acidity, porosity, rehydration, hue and texture, but decreased TSS, when compared to dried control samples. Overall, the results showed the promising potential of PW and PO pretreatments for enhancing drying efficiency and product quality for the food industry.

Gene expression profiling in Rosa roxburghii fruit and overexpressing RrGGP2 in tobacco and tomato indicates the key control point of AsA biosynthesis

Rosa roxburghii Tratt. is an important commercial horticultural crop endemic to China, which is recognized for its extremely high content of L-ascorbic acid (AsA). To understand the mechanisms underlying AsA overproduction in fruit of R. roxburghii, content levels, accumulation rate, and the expression of genes putatively in the biosynthesis of AsA during fruit development have been characterized. The content of AsA increased with fruit weight during development, and AsA accumulation rate was found to be highest between 60 and 90 days after anthesis (DAA), with approximately 60% of the total amount being accumulated during this period. In vitro incubating analysis of 70DAA fruit flesh tissues confirmed that AsA was synthesized mainly via the L-galactose pathway although L-Gulono-1, 4-lactone was also an effective precursor elevating AsA biosynthesis. Furthermore, in transcript level, AsA content was significantly associated with GDP-L-galactose phosphorylase (RrGGP2) gene expression. Virus-induced RrGGP2 silencing reduced the AsA content in R. roxburghii fruit by 28.9%. Overexpressing RrGGP2 increased AsA content by 8-12-fold in tobacco leaves and 2.33-3.11-fold in tomato fruit, respectively, and it showed enhanced resistance to oxidative stress caused by paraquat in transformed tobacco. These results further justified the importance of RrGGP2 as a major control step to AsA biosynthesis in R. roxburghii fruit.

Effects of supplementation of tropical fruit processing by-products on lipid profile, retinol levels and intestinal function in Wistar rats

Fruits agro-industrial by-products may have a great variety of bioactive compounds that promote health. Thus, the effects of supplementation with acerola, cashew and guava processing by-products for 28 days on retinol level, lipid profile and on some aspects related to intestinal function in rats were investigated. The animals supplemented with different fruit by-products presented similar weight gain, faecal pH values and intestinal epithelial structures; however, they showed higher moisture and Lactobacillus spp. and Bifidobacterium spp. counts in faeces compared to the control group. Supplementation with the cashew by-product decreased the blood glucose, acerola and guava by-products reduced serum lipid levels and all fruit by-products tested increased serum and hepatic retinol. The results indicated that acerola and guava by-products possess a potential hypolipidemic effect. The three fruit by-products increase the hepatic retinol deposition and the faecal populations of beneficial bacterial groups and modulated aspects of intestinal function. The findings of this study can contribute to sustainable fruticulture and support future clinical studies with the supplementation of by-products.

A Review on Electrochemical Microsensors for Ascorbic Acid Detection: Clinical, Pharmaceutical, and Food Safety Applications

Nowadays, micro-sized sensors have become a hot topic in electroanalysis. Because of their excellent analytical features, microelectrodes are well-accepted tools for clinical, pharmaceutical, food safety, and environmental applications. In this brief review, we highlight the state-of-art electrochemical non-enzymatic microsensors for quantitative detection of ascorbic acid (also known as vitamin C). Ascorbic acid is a naturally occurring water-soluble organic compound with antioxidant properties and its quantitative determination in biological fluids, foods, cosmetics, etc., using electrochemical microsensors is of wide interest. Various electrochemical techniques have been applied to detect ascorbic acid with extremely high sensitivity, selectivity, reproducibility, and reliability, and apply to in vivo measurements. This review paper aims to give readers a clear view of advances in areas of electrode modification, successful strategies for signal amplification, and miniaturization techniques used in the electroanalytical devices for ascorbic acid. In conclusion, current challenges related to the microelectrodes design, and future perspectives are outlined.

Innovative Processing Technologies to Develop a New Segment of Functional Citrus-Based Beverages: Current and Future Trends

The food industries are interested in developing functional products due to their popularity within nutritional and healthy circles. Functional fruit-based beverages represent one of the fast-growing markets due to the high concentrations of bioactive compounds (BCs), which can be health promoters. Hence, functional beverages based on citrus fruits are a potential way to take advantage of their nutritional and bioactive properties that could attract the interest of consumers. In order to ensure microbial and quality stability, the beverages are subjected to preservation treatment; however, the application of high temperatures leads to the loss of thermolabile BCs. Nowadays, innovative processing technologies (IPT) such as pulsed electric field (PEF), high-pressure processing (HPP), ultrasound processing (US), ohmic heating (OH), and microwave (MW) are a promising alternative due to their efficiency and low impact on juice BCs. The available literature concerning the effects of these technologies in functional fruit-based beverages is scarce; thus, this review gathers the most relevant information about the main positive and negative aspects of the IPT in functional properties, safety, and consumer acceptance of functional citrus-based beverages, as well as the use of citrus by-products to promote the circular economy in citrus processing.

Application of High Hydrostatic Pressure in fresh purple smoothie: Microbial inactivation kinetic modelling and qualitative studies

The inactivation kinetics of Listeria monocytogenes during High Hydrostatic Pressure (HHP) treatments was studied in a purple smoothie based of fresh fruit and vegetables. Pressure intensity studied was 300, 350, 400 and 450 MPa. Untreated samples were used as control. Furthermore, the effects on quality attributes (sensory, total soluble solids content, colour, titratable acidity, pH, vitamin C and total phenolics content) were also monitored. Microbial inactivation was modelled as a function of the HHP intensity using the Geeraerd model. Shoulder and tail effects were observed only for the 300 MPa pressure assayed, supporting a multiple hit kinetic inactivation of critical factors. Increasing the HHP intensity resulted in a faster inactivation with tailing. A strong positive correlation was observed between the pressure level and the inactivation rate (k). Hence, a linear model was used to describe the relationship between both variables. Nevertheless, further data are required to confirm this secondary model. Quality was mostly unaffected by the HHP treatments, except for the vitamin C content, which reported reductions of 26 and 21% after 300 and 350 MPa, respectively. In conclusion, HHP can be a viable technology for processing fruit and vegetable-based smoothies to preserve quality and safety. A pressure of 400 MPa is advisable to ensure an efficient microbial inactivation with the best sensory and nutritional quality retention.

Effect of alginate coatings incorporated with chitinase from ʻBaozhuʼ pear on the preservation of cherry tomato during refrigerated storage

The effects of edible coatings based on sodium alginate with ʻBaozhuʼ pear chitinase on the quality of cherry tomatoes during refrigerated storage were evaluated. Cherry tomatoes inoculated with Fusarium oxysporum were coated and stored up to 21 days. All coatings with the chitinase significantly reduced F. oxysporum proliferation on cherry tomatoes during storage and extended the shelf life of cherry tomatoes effectively (p < .05). Results showed that alginate coatings with the chitinase could prevent weight loss, maintain firmness, and slow down the changes of titratable acidity and vitamin C (p < .05) in a dose‐dependent manner. However, no significant differences were observed between T3 (1% alginate/0.15% ʻBaozhuʼ pear chitinase/1% glycerin) and T4 (1% sodium alginate/0.3% ʻBaozhuʼ pear chitinase/1% glycerin) (p > .05). Overall, alginate coating with 0.15% ʻBaozhuʼ pear chitinase could be a promising method to maintain the quality of cherry tomatoes.

Metabolic engineering in food crops to enhance ascorbic acid production: crop biofortification perspectives for human health

Ascorbic acid (AsA) also known as vitamin C is considered as an essential micronutrient in the diet of humans. The human body is unable to synthesize AsA, thus solely dependent on exogenous sources to accomplish the nutritional requirement. AsA plays a crucial role in different physiological aspects of human health like bone formation, iron absorption, maintenance and development of connective tissues, conversion of cholesterol to bile acid and production of serotonin. It carries antioxidant properties and is involved in curing various clinical disorders such as scurvy, viral infection, neurodegenerative diseases, cardiovascular diseases, anemia, and diabetes. It also plays a significant role in COVID-19 prevention and recovery by improving the oxygen index and enhancing the production of natural killer cells and T-lymphocytes. In plants, AsA plays important role in floral induction, seed germination, senescence, ROS regulation and photosynthesis. AsA is an essential counterpart of the antioxidant system and helps to defend the plants against abiotic and biotic stresses. Surprisingly, the deficiencies of AsA are spreading in both developed and developing countries. The amount of AsA in the major food crops such as wheat, rice, maize, and other raw natural plant foods is inadequate to fulfill its dietary requirements. Hence, the biofortification of AsA in staple crops would be feasible and cost-effective means of delivering AsA to populations that may have limited access to diverse diets and other interventions. In this review, we endeavor to provide information on the role of AsA in plants and human health, and also perused various biotechnological and agronomical approaches for elevating AsA content in food crops.

Applications of Essential Oils as Antibacterial Agents in Minimally Processed Fruits and Vegetables—A Review

Microbial foodborne diseases are a major health concern. In this regard, one of the major risk factors is related to consumer preferences for “ready-to-eat” or minimally processed (MP) fruits and vegetables. Essential oil (EO) is a viable alternative used to reduce pathogenic bacteria and increase the shelf-life of MP foods, due to the health risks associated with food chlorine. Indeed, there has been increased interest in using EO in fresh produce. However, more information about EO applications in MP foods is necessary. For instance, although in vitro tests have defined EO as a valuable antimicrobial agent, its practical use in MP foods can be hampered by unrealistic concentrations, as most studies focus on growth reductions instead of bactericidal activity, which, in the case of MP foods, is of utmost importance. The present review focuses on the effects of EO in MP food pathogens, including the more realistic applications. Overall, due to this type of information, EO could be better regarded as an “added value” to the food industry.

Health benefits and biological activities of spiny monkey orange (Strychnos spinosa Lam.): An African indigenous fruit tree

ETHNOPHARMACOLOGICAL RELEVANCE

Spiny monkey orange (Strychnos spinosa Lam.) is an African endemic fruit tree that is widely consumed by humans and animals for its nutritional value. In folk medicine, different parts of S. spinosa are widely used for the management of the health and well-being of humans and livestock.

AIM

We provide a critical appraisal on the ethnobotanical uses, nutritional and pytochemical as well as the biological activities of S. spinosa.

METHODS

Articles were mined from online databases such as Google Scholar, PubMed, Science Direct, SciELO and SpringerLink. We captured research outputs that aligned with the scope of the review.

RESULTS

Strychnos spinosa remains a commonly consumed fruit due to its high nutritional (e.g. carbohydrates, crude protein and fats) content and energy. In folk medicine, different parts of S. spinosa are prescribed as remedy for diverse medical conditions especially for treating malaria, diabetes, snakebites, skin-related conditions and sexually transmitted infections in humans as well as sleeping sickness in livestock. Together with essential oils, more than 25 compounds have been profiled using Gas chromatography-mass spectrometry (GC-MS), and approximately 45 compounds have been isolated and structurally elucidated using diverse spectroscopic techniques such as UV-visible, Infrared (IR), Nuclear Magnetic Resonance (NMR) and mass spectroscopy (MS). Strychnos spinosa exerts varying degrees of biological activities against different microorganisms (bacteria and fungi) and parasites (plasmodia, trypanosomes and ticks) responsible for many diseases in humans and livestock. Furthermore, low to moderate enzyme-inhibitory effects of S. spinosa extracts suggest its ability to mitigate pains, inflammations and diabetics as well as snakebite venom. Increasing evidence from the in vivo studies support the use of the plant as a popular remedy for managing diabetics in folk medicine. The low cytotoxic effect of the plant extracts against different cell lines could be an indication of its relative safety.

CONCLUSION

Strychnos spinosa exhibits various health-promoting benefits due to its diverse nutritional and phytochemical constituents. Given that the majority of the existing evidence on these aforementioned therapeutic properties and safety are in vitro-based, the clinical significance of these results remain limited.

Synthesis of l-ascorbic acid-amino acid-norcantharidin conjugates and their biological activity evaluation in vitro

Three components of L-ascorbic acid, amino acid and functionalized norcantharidins were constructed together in several steps to form 42 norcantharidin derivatives in a high yield. The structure of these synthesized l-ascorbic acid-amino acid-norcantharidin conjugates are determined by ¹HNMR, ¹³CNMR and MS spectrum. The results showed that compounds 6e, 6g, 6j, 6l, 6m, 6b, 6e, 6i, and 6n showed high cytotoxicity to HepG2 and compounds 6b, 6e-g, 6l, 6n, 7b, 7d, 7h, 7i, 7n, 8g, 8i exhibited high cytotoxicity to SW480; Meanwhile, besides 6b, 6e, 6g, and 6k, the other compounds showed less toxic to LO2 at a concentration of 50 μg/mg after 72 h. Compound 6g can induce Mφ-type macrophages derived from mouse bone marrow to polarize to M1-type macrophages.

Plant Response to Mechanically-Induced Stress: A Case Study on Specialized Metabolites of Leafy Vegetables

Plants have evolved various adaptive mechanisms to environmental stresses, such as sensory mechanisms to detect mechanical stimuli. This plant adaptation has been successfully used in the production practice of leafy vegetables, called mechanical conditioning, for many years, but there is still a lack of research on the effects of mechanically-induced stress on the content of specialized metabolites, or phytochemicals with significant antioxidant activity. Therefore, the aim of this study was to determine the content of specialized metabolites and antioxidant capacity of lettuce and green chicory under the influence of mechanical stimulation by brushing. Mechanically-induced stress had a positive effect on the content of major antioxidants in plant cells, specifically vitamin C, total phenols, and flavonoids. In contrast, no effect of mechanical stimulation was found on the content of pigments, total chlorophylls, and carotenoids. Based on the obtained results, it can be concluded that induced mechanical stress is a good practice in the cultivation of leafy vegetables, the application of which provides high quality plant material with high nutritional potential and significantly higher content of antioxidants and phytochemicals important for human health.

Effect of Alternative Preservation Steps and Storage on Vitamin C Stability in Fruit and Vegetable Products: Critical Review and Kinetic Modelling Approaches

Vitamin C, a water-soluble compound, is a natural antioxidant in many plant-based products, possessing important nutritional benefits for human health. During fruit and vegetable processing, this bioactive compound is prone to various modes of degradation, with temperature and oxygen being recognised as the main factors responsible for this nutritional loss. Consequently, Vitamin C is frequently used as an index of the overall quality deterioration of such products during processing and post-processing storage and handling. Traditional preservation methods, such as thermal processing, drying and freezing, are often linked to a substantial Vitamin C loss. As an alternative, novel techniques or a combination of various preservation steps ("hurdles") have been extensively investigated in the recent literature aiming at maximising Vitamin C retention throughout the whole product lifecycle, from farm to fork. In such an integrated approach, it is important to separately study the effect of each preservation step and mathematically describe the impact of the prevailing factors on Vitamin C stability, so as to be able to optimise the processing/storage phase. In this context, alternative mathematical approaches have been applied, including more sophisticated ones that incorporate parameter uncertainties, with the ultimate goal of providing more realistic predictions.

Effect of high intensity ultrasound on main bioactive compounds, antioxidant capacity and color in orange juice

Ultrasound is a useful alternative to thermal processing that can be applied to many food products and juices to aid with enzymes and microorganism inactivation and to improve the efficiency of unit operations generally applied in the food industry. The aim of this study was to evaluate the effect of a high-intensity sonication treatment (frequency 20 kHz; intensity 39.4 W/cm²) applied for treatment times from 0 to 105 min on the content of polyphenols, vitamin C, organic acids, and carotenoids, and on the hydrophilic and lipophilic antioxidant capacity and color of orange juice. Treatments were performed in triplicate and data was statistically analyzed. Sonication time did not have a significant effect (P > 0.05) on total polyphenols, total vitamin C, organic acid, and carotenoid contents, lipophilic antioxidant capacity, or juice color. The hydrophilic antioxidant activity and the lutein content increased significantly (P < 0.05) with increased sonication time. These results may be useful as a baseline for the development of sonication treatments that could be used in combination with other traditional and emerging processing approaches to protect the most important bioactive compounds and quality properties of orange juice.

Impact of High-Pressure Processing on Antioxidant Activity during Storage of Fruits and Fruit Products: A Review

Fruits and fruit products are an essential part of the human diet. Their health benefits are directly related to their content of valuable bioactive compounds, such as polyphenols, anthocyanins, or vitamins. Heat treatments allow the production of stable and safe products; however, their sensory quality and chemical composition are subject to significant negative changes. The use of emerging non-thermal technologies, such as HPP (High Pressure Processing), has the potential to inactivate the microbial load while exerting minimal effects on the nutritional and organoleptic properties of food products. HPP is an adequate alternative to heat treatments and simultaneously achieves the purposes of preservation and maintenance of freshness characteristics and health benefits of the final products. However, compounds responsible for antioxidant activity can be significantly affected during treatment and storage of HPP-processed products. Therefore, this article reviews the effect of HPP treatment and subsequent storage on the antioxidant activity (oxygen radical absorbance capacity (ORAC) assay), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, ferric reducing antioxidant power (FRAP) assay, 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity assay or Trolox equivalent antioxidant capacity (TEAC) assay), and on the total phenolic, flavonoid, carotenoid, anthocyanin and vitamin contents of fruits and different processed fruit-based products.

Neglected and Underutilized Plant Species (NUS) from the Apulia Region Worthy of Being Rescued and Re-Included in Daily Diet

Neglected and underutilized species (NUS) are cultivated, semi-domesticated, or wild plant species, not included in the group of the major staple crops, since, in most cases, they do not meet the global market requirements. As they often represent resilient species and valuable sources of vitamins, micronutrients, and other phytochemicals, a wider use of NUS would enhance sustainability of agro-systems and a choice of nutritious foods with a strategic role for addressing the nutritional security challenge across Europe. In this review, we focused on some examples of NUS from the Apulia Region (Southern Italy), either cultivated or spontaneously growing species, showing interesting adaptative, nutritional, and economical potential that can be exploited and properly enhanced in future programs.

Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics, Bioactive Compounds Content, and Antioxidant Capacity of Blackcurrant Juice

High-pressure homogenization (HPH) is one of the food-processing methods being tested for use in food preservation as an alternative to pasteurization. The effects of the HPH process on food can vary depending on the process parameters used and product characteristics. The study aimed to investigate the effect of pressure, the number of passes, and the inlet temperature of HPH processing on the quality of cloudy blackcurrant juice as an example of food rich in bioactive compounds. For this purpose, the HPH treatment (pressure of 50, 150, and 220 MPa; one, three, and five passes; inlet temperature at 4 and 20 °C) and the pasteurization of the juice were performed. Titratable acidity, pH, turbidity, anthocyanin, vitamin C, and total phenolics content, as well as colour, and antioxidant activity were measured. Heat treatment significantly decreased the quality of the juice. For processing of the juice, the best were the combinations of the following: one pass, the inlet temperature of 4 °C, any of the used pressures (50, 150, and 220 MPa); and one pass, the inlet temperature of 20 °C, and the pressure of 150 MPa. Vitamin C and anthocyanin degradation have been reported during the HPH. The multiple passes of the juice through the machine were only beneficial in increasing the antioxidant capacity but negatively affected the colour stability.