Chemical perspective and criticism on selected analytical methods used to estimate the total content of phenolic compounds in food matrices

Ultrasound-assisted extraction, optimization, and purification of total flavonoids from Daphnegenkwa and analysis of their antioxidant, anti-inflammatory, and analgesic activities

Daphne genkwa (D. genkwa) is the dried flower buds of a Chinese medicinal plant with multiple biological activities. Response surface methodology (RSM) combined with artificial neural network (ANN) techniques were utilized to optimize ultrasound-assisted extraction conditions for D. genkwa. Antioxidant activity and anti-inflammatory and analgesic properties of total flavonoids from D. genkwa (TFDG) were assessed. Optimal conditions involving ultrasonic power of 225 W, 30 min extraction time, 30 mL/g liquid-solid ratio, 60 °C extraction temperature, and 70% ethanol concentration yielded a maximum total flavonoids content (TFC) of 5.41 mg/g. After microporous resin purification, four specific flavonoids in D. genkwa were identified and quantified using high-performance liquid chromatography (HPLC). The TFDG demonstrated potent antioxidant activity, with a 94% rate of scavenging the 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, TFDG exhibited pain-alleviating properties in hot plate and acetic acid-induced writhing tests and noteworthy inhibitory effects on xylene-induced ear swelling in mice. The total flavonoids extracted by ultrasound had excellent biological activity. This establishes a foundation for further investigation into the potential medical value of D. genkwa.

Potentiometry in determining the antioxidant capacity of compounds of different hydrophilicity in the joint presence using mixed solvents and surfactants

In this work, for the first time, the potentiometric method was used to determine the antioxidant capacity (AOC) of compounds of different hydrophilicity in the joint presence using mixed solvents and surfactants. The AOC of model solutions of antioxidants of different hydrophilicity was determined separately and in the joint presence in the media of phosphate buffer-surfactant and mixed solvents-surfactant, using as an example the ascorbic acid and the α-tocopherol. It was shown that the surfactant Triton X-100 is able to solubilize α-tocopherol under the selected conditions, allows to obtain reproducible and accurate results, and has less effect on the equilibrium rate of the K3[Fe(CN)6]/K4[Fe(CN)6] system. Phosphate buffer-ethanol and phosphate buffer-acetonitrile media in the 3:2 ratio with Triton X-100 (5 mmol/dm3) were chosen as the analysis conditions (RSD ≤ 6%). The range of determined concentrations was (0.006-0.5) m mmol/dm3 in phosphate buffer-ethanol and (0.006-0.3) m mmol/dm3 in phosphate buffer-acetonitrile. AOC of raw materials infusions was determined in selected media. The positive correlation with the well-known Folin-Ciocalteu assay was obtained.

Buriti (Mauritia flexuosa) shell flour: Nutritional composition, chemical profile, and antioxidant potential as a strategy for valuing waste from native Brazilian fruits

The Cerrado is one of the most biodiverse biomes in the world, characterized by a wealth of native fruits with unique nutritional characteristics. In this sense, the social, economic, and environmental importance of fully utilizing food is widely recognized. Therefore, generally considered waste, fruit shells can be transformed into a coproduct with high added value. The objective of this work was to carry out a comprehensive assessment of the physicochemical properties, carbohydrate and fatty acid profile, phytochemical compounds, phenolic profile, and antioxidant potential of the recovered extracts of buriti (Mauritia flexuosa) shells in natura and dehydrated at 55 °C (flour). In addition, the functional properties were verified by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) from buriti shell flour. The results indicated high fiber content and energy value for the sample processed at 55 °C (58.95 g/100 g and 378.91 kcal/100 g, respectively) and low lipid and protein content (1.03 g/100 g and 1.39 g/100 g, respectively). Regardless of the sample analyzed, maltose was the majority sugar (37.33 - 281.01 g/100 g). The main fatty acids detected were oleic acid (61.33 - 62.08 %) followed by palmitic acid (33.91 - 34.40 %). The analysis of the mineral profile demonstrated that the samples did not differ significantly from each other, showing that the drying process did not interfere with the results obtained (p ≤ 0.05). The analysis of individual phenolics allowed the identification of six phenolic compounds in buriti shells. However, it is possible to observe that the drying method had a positive and significant influence on the phenolic profile (p ≤ 0.05), with chlorogenic acid (2.63 - 8.27 mg/100 g) and trigonelline (1.06 - 41.52 mg/100 g), the majority compounds. On the other hand, it is important to highlight that buriti shells have a high content of carotenoids, mainly β-carotene (27.18 - 62.94 µg/100 g) and α-carotene (18.23 - 60.28 µg/100 g), also being positively influenced by the drying process at 55 °C (p ≤ 0.05). The dried shells showed a high content of phytochemical compounds and high antioxidant activity based on the different methods tested. The results show that buriti shell flour can be fully utilized and has nutritional and chemical aspects that can be applied to develop new sustainable, nutritious, and functional food formulations.

Characterization of halotolerant microalga isolated from waterlogged habitats: Deciphering the biochemical profiling and unraveling the molecular identity

The primary objective of this study was to comprehensively explore the biochemical profile of the novel halotolerant microalgae strain, biogas laboratory scenedesmus (BGLRS), previously isolated from waterlogged regions in the southwest zone of Punjab, India. To achieve this, three distinct drying methods viz. freeze-drying, oven-drying, and shade-drying were employed and biochemical composition and antioxidant analyses on the microalgal biomass were conducted. Utilizing advanced analytical techniques, including high-performance liquid chromatography (HPLC), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and gas chromatography-mass spectroscopy (GC-MS) on freeze-dried biomass, its carbohydrate profile, micronutrient composition, and presence of bioactive compounds with potential therapeutic and nutraceutical significance were sought to unravel. Among the drying methods evaluated, freeze-drying exhibited the most promising experimental results, prompting its selection for further investigation. Notably, ICP-AES unveiled elevated concentrations of essential elements such as calcium, iron, magnesium, and phosphorus in BGLRS, with negligible traces of heavy metals, underscoring its safety for human consumption. GC-MS analysis further divulged the existence of numerous biologically active compounds, indicating potential applications in medical and nutraceutical fields. Through molecular identification using sequencing of the internal transcribed spacer (ITS) region, a close taxonomic resemblance between BGLRS and Scenedesmus sp. MKB was established, solidifying its unique position within the microalgal taxonomy. The deposition of ITS sequences into the NCBI GenBank, obtaining accession number MN796425, attests to the rigor and transparency of this research. Overall, these findings strongly suggest that microalgae BGLRS possesses high-quality biochemical attributes of significant therapeutic and nutraceutical importance.

An analytical approach to determine the health benefits and health risks of consuming berry juices

Food products composition analysis is a prerequisite for verification of product quality, fulfillment of regulatory enforcements, checking compliance with national and international food standards, contracting specifications, and nutrient labeling requirements and providing quality assurance for use of the product for the supplementation of other foods. These aspects also apply to the berry fruit and berry juice. It also must be noted that even though fruit juices are generally considered healthy, there are many risks associated with mishandling both fruits and juices themselves. The review gathers information related with the health benefits and risk associated with the consumption of berry fruit juices. Moreover, the focus was paid to the quality assurance of berry fruit juice. Thus, the analytical methods used for determination of compounds influencing the sensory and nutritional characteristics of fruit juice as well as potential contaminants or adulterations.

Exploring for HPLC-MS/MS Profiles and Biological Activities of Different Extracts from Allium lycaonicum Siehe ex Hayek from Turkey Flora

The present study was designed to determine the phenolic constituents, antioxidant, and enzyme inhibition activities of aerial parts and bulbs of Allium lycaonicum (family Amaryllidaceae). Extracts were prepared by maceration and Soxhlet/infusion using hexane, methanol, and water as extraction solvents. Generally, extracts from the aerial parts showed higher total phenolic and individual components and antioxidant activity than their respective bulb extracts. Maceration with water was the best to extract total phenolic content from the aerial parts (29.00 mg gallic acid equivalents (GAE)/g), while the Soxhlet extraction with hexane (22.29 mg GAE/g) was the best for the bulb. Maceration with methanol recovered the highest total flavonoid content from both the aerial parts (41.95 mg (rutin equivalents (RE)/g) and bulb (1.83 mg RE/g). Polar extracts of aerial parts were characterized by higher abundance of kaempferol-3-glucoside (≤20,624.27 µg/mg), hyperoside (≤19,722.76 µg/g), isoquercitrin (≤17,270.70 µg/g), delphindin-3,5-diglucoside (≤14,625.21 µg/g), and rutin (≤10,901.61 µg/g) than the bulb. Aerial parts' aqueous extract, prepared by maceration, exerted the highest anti-ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical activity (64.09 mg trolox equivalents (TE)/g), Cu++ (83.03 mg TE/g) and Fe+++ (63.03 mg TE/g) reducing capacity while that prepared by infusion recorded the highest anti-DPPH (2,2-diphenyl-1-picrylhydrazyl) radical (31.70 mg TE/g) and metal chelating (27.66 mg EDTAE/g) activities. The highest total antioxidant activity (1.46 mmol TE/g) was obtained by maceration of the bulb with water. Extracts obtained by organic solvents showed remarkable enzyme inhibition properties against the tested enzymes. Soxhlet extraction of the bulb with hexane and methanol recorded the highest acetylcholinesterase inhibition (4.75 mg galanthamine equivalents (GALAE)/g) and tyrosinase inhibition (139.95 mg kojic acid equivalents/g) activities, respectively. Extracts obtained by maceration of the bulb with methanol and the aerial parts with hexane exerted the highest glucosidase inhibition (3.25 mmol acarbose equivalents/g) and butyrylcholinesterase inhibition (20.99 mg GALAE/g) activities, respectively. These data indicated that A. lycaonicum is a source of bioactive molecules with potential antioxidant and enzyme inhibition properties. Nonetheless, the extracts obtained through various solvents and extraction techniques showed variations in their phytoconstituent composition and biological properties.

Valorization of Wild Edible Plants as Food Ingredients and Their Economic Value

(1) Background: Wild Edible Plants (WEPs) are plants that grow without human help, by simply using the available resources. These types of plants are undervalued, because there is a lack of knowledge about their bioactive composition and nutritional/functional potential. (2) Scope and Approach: The main aim of this review is to fully identify the potential uses and importance of WEPs in certain regions based on (i) their sustainability, because they grow with their own resources, (ii) their content of bioactive compounds and consequently nutritional and functional value, (iii) their socio-economic relevance, and (iv) their ability to be useful in the agri-food industry in the short term. (3) Results: This review found evidence that a consumption of between 100 and 200 g of some of these WEPs can cover up to 50% of the recommended daily intake of proteins and fiber, being also a natural source of macro- and micro-minerals. Regarding their bioactive composition, most of these plants contain phenolic compounds and flavonoids, which determine their antioxidant capacity. (4) Conclusions: These reported results clearly demonstrate the high potential of the WEPs from a nutritional, economic and social point of view; although further studies are needed to gather deeper scientific information about their potential role in the socio-economic sustainability of specific groups of farmers worldwide.

Chemical and nutritional characterization of Ambelania duckei (Apocynaceae) an unexplored fruit from the Amazon region

Ambelania duckei Markgr is a species of the Apocynaceae family, native to the Amazon region that is unexplored from a nutritional point of view and studied in relation to its chemical constituents. This work presents an unprecedented study of the proximate composition, lipid profile, a chromatographic analysis, and the antioxidant activity of extracts obtained from the pulp, peel and seeds of the fruit. The results showed that potassium, calcium, and magnesium stood out as the most abundant key minerals in the fruit peel and pulp, with an emphasis on the potassium present in the fruit pulp at 1750.0 mg/100 g. The peel had the highest content of total phenolics (374.86 mg/g), flavonoids (15.54 mg/g), tannins (27.45 mg/g) and O-diphenols (379.36 mg/g; 645.71 mg/g). The antioxidant activity (AA) was highest in the peel compared to the pulp in the DPPH, ABTS, and ORAC tests showing: IC₅₀ of 29.82; 43.67; and 407.13 µg/mL, respectively but a lower activity for the Fe²⁺ chelator. The analysis of the lipid fractions from the peel, pulp, and seeds of the A. duckei fruit resulted in 14 types of fatty acids. The major fatty acids found in the three parts of the fruit were oleic acid (peel, 22.52 %), palmitic acid (pulp, 17.34 %), and linoleic acid (seeds, 47.99 %). The lipid profile and nutritional aspects had a PUFA/SFA ratio (0.4-1.8) in the different parts of the A. duckei fruit; the atherogenic and thrombogenic indexes were higher in the peel (1.23) and pulp (0.62), respectively. The ratio between the hypocholesterolemic and hypercholesterolemic fatty acids (0.5 - 3.8) calculated for the fruit are within the desirable range for a nutritious food. The chromatographic analysis of the volatile organic compounds (VOCs) from the peel and pulp of the fruit, identified 74 VOCs, of which 60.9 % are related to terpenes, and emit notes such as cucumber, green, fatty, floral, and mint, due to the presence of substances with OAVs > 10, especially α-ionone, 1,8-cineole, 2,4-decadienal, and dodecanal. The analysis of the MS and MS/MS spectra of the chromatograms obtained by LC- QTOF-HRMS led to the identification of 26 compounds in the peel, seeds and pulp of A. duckei, such as fatty acids, phenolic acid, flavonoids, proanthocyanidins, alkaloids, and terpenoids. The results show that the pulp of A. duckei has potential as nourishing food and the nutritional and chemical aspects of the peel can be applied to commercial applications.

Plant-based pecan nut cake beverage enrichment of phytochemicals and antioxidant properties using multi-stage block freeze concentration

Pecan nut (Carya illinoinensis) processing to obtain oil generates circa 37% of press cake, which is currently underutilized and primarily employed as animal feed. Due to its nutritional- and bioactive-rich composition, pecan nut cake (PNC) can be used as raw material for plant-based beverages, whose properties may be enhanced using a non-thermal technology based on block freeze concentration (BFC). The effect of five-stage BFC on total solids content (TSC), pH, color parameters, retention of phytochemicals, and the antioxidant activity (AA) of a pecan nut cake beverage (PNB) was assessed in this work. BFC afforded 98% (w/w) solids retention after three stages and 85% efficiency after four stages. The process also provided a 254% concentration factor in stage 5. In the last step, approximately a 64% increase in TSC and a slight decrease (7.3%) in pH compared to the control PNB was observed. In addition, total phenolic compounds, condensed tannins, total flavonols, and AA were significantly (P < 0.05) improved after the BFC, resulting in a 2.6-10.2- and 1.9-5.8-fold increase in phytochemicals and antioxidants, respectively. On the other hand, BFC caused the darkening of concentrates due to TSC and bioactive compounds retention. The processing strategy evaluated herein indicated a great potential of PNC as a raw material for obtaining high-quality ingredients for the food industry, which may reduce agro-industrial waste production and add value to a coproduct rich in nutrients and biocompounds with potential biological activity.

Graphical Abstract

Polyphenols for Livestock Feed: Sustainable Perspectives for Animal Husbandry?

There is growing interest in specialized metabolites for fortification strategies in feed and/or as an antioxidant, anti-inflammatory and antimicrobial alternative for the containment of disorders/pathologies that can also badly impact human nutrition. In this context, the improvement of the diet of ruminant species with polyphenols and the influence of these compounds on animal performance, biohydrogenation processes, methanogenesis, and quality and quantity of milk have been extensively investigated through in vitro and in vivo studies. Often conflicting results emerge from a review of the literature of recent years. However, the data suggest pursuing a deepening of the role of phenols and polyphenols in ruminant feeding, paying greater attention to the chemistry of the single compound or to that of the mixture of compounds more commonly used for investigative purposes.

Unravelling Phytochemical and Bioactive Potential of Three Hypericum Species from Romanian Spontaneous Flora: H. alpigenum, H. perforatum and H. rochelii

Hypericum perforatum L., also known as St. John’s Wort, is recognized worldwide as a valuable medicinal herb; however, other Hypericum species were intensively studied for their bioactive potential. To fill the research gap that exists in the scientific literature, a comparative evaluation between H. alpigenum Kit., H. perforatum L. and H. rochelii Griseb. & Schenk was conducted in the present study. Two types of herbal preparations obtained from the aerial parts of these species were analyzed: extracts obtained through maceration and extracts obtained through magnetic-stirring-assisted extraction. LC-DAD-ESI-MSn analysis revealed the presence of phenolic acids, flavan-3-ols and flavonoid derivatives as the main constituents of the above-mentioned species. Moreover, all extracts were tested for their antioxidant, enzyme-inhibitory and antimicrobial potential. Our work emphasizes for the first time a detailed description of H. rochelii phenolic fractions, including their phytochemical and bioactive characterization. In comparison with the other two studied species, H. rochelii was found as a rich source of phenolic acids and myricetin derivatives, showing important antioxidant, anticholinesterase and antibacterial activity. The study offers new perspectives regarding the chemical and bioactive profile of the less-studied species H. alpigenum and H. rochelii.

Valorization of Traditional Alcoholic Beverages: The Study of the Sicilian Amarena Wine during Bottle Aging

Traditional alcoholic beverages have always been part of the Mediterranean culture and, lately, they have been re-evaluated to valorize both the territory and local customs. In this study, the Amarena wine, a fortified wine included in the national list of the traditional agri-food products, was characterized during bottle aging for oenological parameters, chromaticity, volatiles, and inorganic elements. Then, experimental data were visually interpreted by a principal component analysis (PCA). PCA revealed that most of oenological parameters (i.e., alcoholic grade, total dry extract, sugars, organic acids, and phenolic compounds) had a scarce discriminating power. Additionally, ethyl esters were only present in younger products, while remaining at quite constant levels. Conversely, certain metals (i.e., Mg, Na, Mn, Zn, and Cu), chromatic properties, and pH differentiated older Amarena bottles from the younger counterpart. Particularly, acetaldehyde and furanic compounds proved to be valid aging markers. A sensorial analysis highlighted that fruity and floral odors and flavors characterized younger beverages, while dried fruity, nutty, and spicy notes were displayed by older products, along with the valuable attribute of “oxidized” typically observed in aged Sherry wines. Overall, this study may encourage the production and commercialization of the Amarena wine, thus preserving the cultural heritage of the Mediterranean area.

Quantitative Structure-Property Relationship (QSPR) of Plant Phenolic Compounds in Rapeseed Oil and Comparison of Antioxidant Measurement Methods

Natural antioxidants are known for their ability to scavenge free radicals and protect oils from oxidation. Our aim was to study the structural properties such as the number of hydroxyl groups and Bors criteria of phenolic substances leading to high antioxidant activity in oil in order to analyze common trends and differences in widespread in vitro antioxidant assays. Therefore, 20 different phenolic substances were incorporated into rapeseed oil and were measured using pressurized differential scanning calorimetry (P-DSC) and the Rancimat method. The Bors criteria had the highest influence on the antioxidant effect in rapeseed oil, which is why myricetin (MYR), fulfilling all Bors criteria, reached the highest result of the flavonoids. In the Rancimat test and P-DSC, MYR obtained an increase in oxidation induction time (OIT) of 231.1 ± 44.6% and 96.8 ± 1.8%, respectively. Due to differences in the measurement parameters, the results of the Rancimat test and P-DSC were only partially in agreement. Furthermore, we compared the results to in vitro assays (ABTS, DPPH, FC and ORAC) in order to evaluate their applicability as alternative rapid methods. These analysis showed the highest correlation of the oil methods with the results of the DPPH assay, which is, therefore, most suitable to predict the antioxidant behavior of oil.

Leaf necrosis resulting from downregulation of poplar glycosyltransferase UGT72A2

Reactive species (RS) causing oxidative stress are unavoidable by-products of various plant metabolic processes, such as photosynthesis, respiration or photorespiration. In leaves, flavonoids scavenge RS produced during photosynthesis and protect plant cells against deleterious oxidative damages. Their biosynthesis and accumulation are therefore under tight regulation at the cellular level. Glycosylation has emerged as an essential biochemical reaction in the homeostasis of various specialized metabolites such as flavonoids. This article provides a functional characterization of the Populus tremula x P. alba (poplar) UGT72A2 coding for a UDP-glycosyltransferase that is localized in the chloroplasts. Compared with the wild type, transgenic poplar lines with decreased expression of UGT72A2 are characterized by reduced growth and oxidative damages in leaves, as evidenced by necrosis, higher content of glutathione and lipid peroxidation products as well as diminished soluble peroxidase activity and NADPH to NADP+ ratio under standard growing conditions. They furthermore display lower pools of phenolics, anthocyanins and total flavonoids but higher proanthocyanidins content. Promoter analysis revealed the presence of cis-elements involved in photomorphogenesis, chloroplast biogenesis and flavonoid biosynthesis. The UGT72A2 is regulated by the poplar MYB119, a transcription factor known to regulate the flavonoid biosynthesis pathway. Phylogenetic analysis and molecular docking suggest that UGT72A2 could glycosylate flavonoids; however, the actual substrate(s) was not consistently evidenced with either in vitro assays nor analyses of glycosylated products in leaves of transgenic poplar overexpressing or downregulated for UGT72A2. This article provides elements highlighting the importance of flavonoid glycosylation regarding protection against oxidative stress in poplar leaves and raises new questions about the link between this biochemical reaction and regulation of the redox homeostasis system.

Extraction and Characterization of Flavanol-Rich Nutraceuticals Based on High-Performance Liquid Chromatography

Flavanols are a class of polyphenols that have become the focus of much research because of their medicinal properties. For this paper, a new method to determine polyphenols in nutraceutical samples was developed, based on solid-liquid extraction and further analysis by liquid chromatography. Analytes were recovered by ultrasound-assisted extraction, using a mixture of methanol/water/hydrochloric acid (70:29:1, v:v:v) as the solvent. Reversed-phase high-performance liquid chromatography with ultraviolet/visible (HPLC-UV/Vis) and fluorescence detection (HPLC-FLD) were developed to determine the content of the principal flavanols. The HPLC-FLD method showed better selectivity and sensitivity, so it was selected for further studies. The analytical parameters established with FLD were satisfactory in terms of linearity (R2 ≥ 0.993), repeatability (RSD% ≥ 2.2), and limits of detection of 0.1 mg L−1 or below. The nutraceutical samples were analyzed by HPLC-FLD to determine the compositional profiles of flavanols, then they were subsequently treated using chemometric methods, such as principal component analysis (PCA). Results showed that the study of compositional profiles from the selected flavanols was sufficient for description and discrimination purposes. The cranberry samples were the richest in flavanols, procyanidin A2 being the principal flavanol, and artichoke samples the least rich.

Role of polyphenols in combating Type 2 Diabetes and insulin resistance

Compromised carbohydrate metabolism leading to hyperglycemia is the primary metabolic disorder of non-insulin-dependent diabetes mellitus. Reformed digestion and altered absorption of carbohydrates, exhaustion of glycogen stock, enhanced gluconeogenesis and overproduced hepatic glucose, dysfunction of β-cell, resistance to insulin in peripheral tissue, and impaired insulin signaling pathways are essential reasons for hyperglycemia. Although oral anti-diabetic drugs like α-glucosidase inhibitors, sulfonylureas and insulin therapies are commonly used to manage Type 2 Diabetes (T2D) and hyperglycemia, natural compounds in diet also play a significant role in combating the effect of diabetes. Due to their vast bioavailability and anti-hyperglycemic effect with least or no side effects, polyphenolic compounds have gained wide popularity. Polyphenols such as flavonoids and tannins play a significant role in carbohydrate metabolism by inhibiting key enzymes responsible for the digestion of carbohydrates to glucose like α-glucosidase and α-amylase. Several polyphenols such as resveratrol, epigallocatechin-3-gallate (EGCG) and quercetin enhanced glucose uptake in the muscle and adipocytes by translocating GLUT4 to plasma membrane mainly by the activation of the AMP-activated protein kinase (AMPK) pathway. This review provides an insight into the protective role of polyphenols in T2D, highlighting the aspects of insulin resistance.

Optimized ultrasound-assisted extraction of phenolic compounds from Thymus comosus Heuff. ex Griseb. et Schenk (wild thyme) and their bioactive potential

An optimized ultrasound-assisted extractive method was developed to obtain a polyphenol-enriched extract from the aerial parts of Thymus comosus Heuff. ex Griseb. et Schenk. Optimization process was conducted based on Design of Experiment (DoE) principles, determining the influence of three independent variables (time, ultrasound amplitude, ethanol concentration) on the total phenolic content of the extract (dependent variable). Additionally, the phenolic composition of the extract was characterized through UHPLC-HRMS, revealing beside the most abundant flavonoid-type compounds the presence of salvianolic acids C, D and L in high amounts. Phytochemical profile of the extract was correlated with its antioxidant activity (tested through five complementary assays) and enzyme-inhibitory potential, showing important antiglucosidase and anticholinesterase effects. Overall, it was concluded that the developed method is suitable for obtaining a good recovery of both phenolic and non-phenolic compounds from Thymus comosus aerial parts, and their presence in the optimized extract is responsible for its pharmacological potential.

Design and Antioxidant Properties of Bifunctional 2H-Imidazole-Derived Phenolic Compounds-A New Family of Effective Inhibitors for Oxidative Stress-Associated Destructive Processes

The synthesis of inhibitors for oxidative stress-associated destructive processes based on 2H-imidazole-derived phenolic compounds affording the bifunctional 2H-imidazole-derived phenolic compounds in good-to-excellent yields was reported. In particular, a series of bifunctional organic molecules of the 5-aryl-2H-imidazole family of various architectures bearing both electron-donating and electron-withdrawing substituents in the aryl fragment along with the different arrangements of the hydroxy groups in the polyphenol moiety, namely derivatives of phloroglucinol, pyrogallol, hydroxyquinol, including previously unknown water-soluble molecules, were studied. The structural and antioxidant properties of these bifunctional 5-aryl-2H-imidazoles were comprehensively studied. The redox transformations of the synthesized compounds were carried out. The integrated approach based on single and mixed mechanisms of antioxidant action, namely the AOC, ARC, Folin, and DPPH assays, were applied to estimate antioxidant activities. The relationship “structure-antioxidant properties” was established for each of the antioxidant action mechanisms. The conjugation effect was shown to result in a decrease in the mobility of the hydrogen atom, thus complicating the process of electron transfer in nearly all cases. On the contrary, the conjugation in imidazolyl substituted phloroglucinols was found to enhance their activity through the hydrogen transfer mechanism. Imidazole-derived polyphenolic compounds bearing the most electron-withdrawing functionality, namely the nitro group, were established to possess the higher values for both antioxidant and antiradical capacities. It was demonstrated that in the case of phloroglucinol derivatives, the conjugation effect resulted in a significant increase in the antiradical capacity (ARC) for a whole family of the considered 2H-imidazole-derived phenolic compounds in comparison with the corresponding unsubstituted phenols. Particularly, conjugation of the polyphenolic subunit with 2,2-dimethyl-5-(4-nitrophenyl)-2H-imidazol-4-yl fragment was shown to increase ARC from 2.26 to 5.16 (10⁴ mol-eq/L). This means that the considered family of compounds is capable of exhibiting an antioxidant activity via transferring a hydrogen atom, exceeding the activity of known natural polyphenolic compounds.

Characterization and Classification of Cocoa Bean Shells from Different Regions of Venezuela Using HPLC-PDA-MS/MS and Spectrophotometric Techniques Coupled to Chemometric Analysis

The cocoa bean shell (CBS) is one of the main cocoa byproducts with a prospective to be used as a functional food ingredient due to its nutritional and sensory properties. This study aims to define the chemical fingerprint of CBSs obtained from cocoa beans of diverse cultivars and collected in different geographical areas of Venezuela assessed using high-performance liquid chromatography coupled to photodiodes array and mass spectrometry (HPLC-PDA-MS/MS) and spectrophotometric assays combined with multivariate analysis for classification purposes. The study provides a comprehensive fingerprint and quantitative data for 39 compounds, including methylxanthines and several polyphenols, such as flavan-3-ols, procyanidins, and N-phenylpropenoyl amino acids. Several key cocoa markers, such as theobromine, epicatechin, quercetin-3-O-glucoside, procyanidin_A pentoside_3, and N-coumaroyl-l-aspartate_2, were found suitable for the classification of CBS according to their cultivar and origin. Despite the screening methods required a previous purification of the sample, both methodologies appear to be suitable for the classification of CBS with a high correlation between datasets. Finally, preliminary findings on the identification of potential contributors for the radical scavenging activity of CBS were also accomplished to support the valorization of this byproduct as a bioactive ingredient in the production of functional foods.

Cladodes: Chemical and structural properties, biological activity, and polyphenols profile

The nopal cactus is an essential part of the Mexican diet and culture. The per capita consumption of young cladodes averages annually to 6.4 kg across the nation. In addition to contributing to the country's food culture, the nopal is considered a food with functional characteristics since, in addition to providing fiber, an important group of polyphenolic compounds is present, which has given cladodes to be considered a healthy food, for what they have been incorporated into the diet of Mexican people and many other countries worldwide. Research suggests that polyphenols from cladodes act as antioxidants and antidiabetics. This review studies the main phenolic components in cladodes and summarizes both conventional and novel methods to identify them.

Characterisation and in vivo evaluation of Araucaria angustifolia pinhão seed coat nanosuspension as a functional food source

Araucaria angustifolia seeds from South America are culturally important; however, the seed coat is generally discarded and it has yet to find a beneficial commercial impact. Herein, we propose a new formulation for the use of the seed coat for the production of a food source. A nanosuspension was developed under two conditions, bleached and unbleached treatment. Initial characterisation of the seed coat, as well as the nanosuspension, was conducted, in which nanofibrils with antioxidant activity and high values of phenol and sterol classes with health-promoting ability were detected by GC-MS; however, after bleaching, the compounds were removed. The nanosuspension induced a decrease in cholesterol, triglycerides, glucose levels and weight gain when added to the daily rat diet. No significant differences were determined when bleach treatment was used, suggesting that dietary fibre plays a more significant role. Histology analysis and biochemical markers reported no toxicity from the rat ingestion of the nanoformulation.

Tanacetum vulgare L. (Tansy) as an effective bioresource with promising pharmacological effects from natural arsenal

The Tanacetum genus is a big treasure with the presence of biologically-active compounds and members of this genus are widely used for the treatment of several diseases in traditional medicine system. Considering this fact, we aimed to analyze the extracts from Tanacetum vulgare L. in case of chemical profiles and biological effects. Chemical characterization was performed by using UHPLC-HRMS technique and showed the presence of several phytochemical groups (107 compounds were identified, including phenolic acids, flavonoids, terpenoids and fatty acids. Biological abilities were examined by using antioxidant (DPPH, ABTS, FRAP, CUPRAC, metal chelating and phosphomolybdenum assays) and enzyme inhibition (tyrosinase, amylase, glucosidase and cholinesterase) properties. Pharmaco-toxicological investigations were also performed with the aim to identify limits of biocompatibility, anti-oxidant and neuromodulatory effects, in hypothalamic HypoE22 cells. A bioinformatic analysis was also carried to unravel the putative protein-targets for the observed biological effects. Generally, the tested hexane and hydroalcoholic extracts displayed stronger activities in antioxidant and enzyme inhibitory assays, when compared with water. In addition, multivariate analysis was performed to understand the differences in both solvents and plant parts and we clearly observed the separation of these parameters. The extracts (10 μg/mL) also stimulated DAT and inhibited TNFα and BDNF gene expression, in HypoE22 cells. In parallel, the extracts were also able to stimulate norepinephrine release from this cell line. By contrast, in the concentration range 50-100 μg/mL, the extracts reduced the HypoE22 viability, thus demonstrating cytotoxicity at concentrations 5-10 fold higher compared to those effective as neuromodulatory. Our observations manifested that T. vulgare has several beneficial effects and it can be used as a potential natural raw material for designing further health-promoting applications in nutraceutical, cosmeceutical, and pharmaceutical areas.

Liquid Chromatographic Fingerprints for the Characterization of Flavanol-Rich Nutraceuticals Based on 4-Dimethylaminocinnamaldehyde Precolumn Derivatization

Flavanols consist of a great family of bioactive molecules displaying a wide range of health-promoting attributes for humans, including antioxidant, antimicrobial or anti-inflammatory effects. As a result, botanical species rich in this type of compound are often used to develop nutraceutical products or dietary supplements with recognized healthy attributes. This paper aims at characterizing nutraceutical products using liquid chromatographic fingerprints related to flavanol composition. Catechins and their oligomers were exploited to characterize and authenticate various commercial products prepared with extracts of red berries and medicinal plants. These compounds resulted in interesting descriptors of some fruits and vegetables, thus providing an additional perspective for the study of nutraceuticals. For such a purpose, a new method based on liquid chromatography with UV/Vis detection (HPLC–UV/Vis) with precolumn derivatization with 4-dimethylaminocinnamaldehyde was developed. Results indicated that the separation of flavanols was very complex due to the degradation of procyanidin derivatives. The resulting data sets were analyzed using chemometric methods such as principal component analysis and partial least square–discriminant analysis. Despite the complexity of chromatographic fingerprints, nutraceutical samples could be discriminated according to their main ingredients. In general, catechin and epicatechin were the most abundant compounds in the different samples, and procyanidin A2 was highly specific to cranberry.

Evaluation of polyphenols enriched dairy products developed by incorporating black carrot (Daucus carota L.) concentrate

BACKGROUND

Dairy products like ice cream, yogurt and buttermilk are consumed widely due to their rich taste but these products lack anthocyanins, which are polyphenol and exhibit great antioxidant activity in both in vivo and in vitro studies. Therefore, adding a natural source of these antioxidants to the commonly consumed dairy product will be beneficial to the masses. Among all the sources, black carrots are the extraordinary and cheapest source of anthocyanins, which are commonly consumed as a natural fermented drink. In this study, an attempt has been made to examine the feasibility of black carrot concentrate as an ingredient into dairy products.

METHODOLOGY

Ice cream, yogurt and buttermilk were prepared by incorporating black carrot concentrate at 2.5, 5.0, 7.5 and 10% level and were subjected to sensory analysis. The most acceptable products with 7.5% black carrot concentrate were analyzed for minerals, polyphenols and antioxidant activity. Effects of storage on physicochemical, microbial and sensory attributes of black carrot concentrate incorporated dairy products were further analyzed.

RESULTS

Sensory analysis revealed that black carrot concentrate could be used up to 7.5% as an ingredient into dairy product with high acceptability. Significant improvement in mineral content (Mg and Fe), polyphenols and antioxidant activity were reported in black carrot concentrate added dairy products. Developed dairy products exhibited an excellent amount of 24.52-113.27 mg/100g anthocyanins. Flavonoids increased by 14.52-34.62 times and Folin-Ciocalteu reducing capacity increased by 26.39-35.87 times in experimental dairy products. The storage study revealed that ice cream could be stored for more than 60 days, yogurt up to 5 days and buttermilk up to 10 days with excellent stability attributes.

CONCLUSION

Incorporation of black carrot concentrate at the level of 7.5% resulted in high acceptability and exceptional nutraceutical property of dairy products. Incorporation of black carrot concentrate into dairy products would enhance the nutraceutical properties and mineral content of food, which could be highly significant in preventing hidden hunger and oxidative stress-induced disorders in developing countries.

COMPARATIVE ACTIVITY OF TOTAL POLYPHENOLS AND ANTIOXIDANT COMPOUNDS FROM UNCARIA TOMENTOSA ENHANCED WITH CITRIC ACID

Uncaria tomentosa, a climbing vine notable for containing high concentrations of oxindole alkaloids and phenolic compounds, is commonly used in traditional medicine as an anti-inflammatory and antioxidant agent. Also, the citric acid is a food additive widely used for conservation, due to its low cost. In this way, this study aims to evaluate the content of phenolic compounds from Uncaria tomentosa and investigate its antioxidant activity when citric acid, at different concentrations, is added to the extract. For this purpose, a gradient of citric acid concentrations was established, and the antioxidant profile from a aqueous extracts of the plant leaves and bark was analyzed by Folin-Ciocalteu essay; inhibition of the free radical of 2,2-diphenyl-1-picrylhydrazyl (DPPH); ferric reducing antioxidant power (FRAP), and scavenging capacity of cationic free radicals of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The results showed a synergistic effect between citric acid and antioxidant compounds from Uncaria tomentosa, presenting highly statistical significance, the synergistic effect was more efficient in the bark than in the leaves.

Diversity of Italian red wines: A study by enological parameters, color, and phenolic indices

An extensive survey was conducted on 110 Italian monovarietal red wines from a single vintage to determine their standard compositional, color, and phenolic characteristics, analysing more than 35 parameters evaluated through methods commonly used in the wine industry. 'Primitivo' achieved the highest average alcohol strength (15.4% v/v) and dry extract values, while 'Cannonau' showed the lowest total acidity. 'Corvina' had the lowest phenolic content (1065 mg/L by Folin-Ciocalteu assay), remarkably different from the highest found in 'Sagrantino' (3578 mg/L), the latter being also the richest variety in both proanthocyanidins and vanillin-reactive flavanols. 'Teroldego' wines were the richest in both total and monomeric anthocyanins (702 and 315 mg/L, respectively), followed by 'Aglianico' and 'Raboso Piave', while 'Corvina', 'Nebbiolo', and 'Nerello Mascalese' were the poorest. 'Montepulciano' and 'Sangiovese' showed intermediate values for the majority of the parameters analyzed. A multivariate PCA-DA approach allowed achieving both a classification of the different wines as well as the discrimination of 'Sangiovese' wines produced in two regions (Emilia Romagna and Toscana) that returned a 42-66% success rate depending on the zone considered. Taking into account the number and diversity of the wines analyzed, a correlation study helped in better understanding the underlying relations between the most common and widespread analytical techniques for phenolic and color determinations.

Development of the method for standardization of the medicinal plant raw material of Cichorium intybus L. herb by the total amount of hydroxycinnamic acid derivatives

The purpose of the research is to work out a routine method for the quantitative determination of the total amount of hydroxycinnamic acids in chicory herb growing in Ukraine. The presence of chlorogenic and caffeic acids was experimentally proven by comparing the TLC profiles of solutions of the chicory extract and standard substances of hydroxycinnamic acids. According to the chromatogram, the chemical composition of the ethanol extracts was qualitatively constant and did not depend on the series of plants collected in different places (7 regions of Ukraine) and in different years (2017 and 2018). The water-alcohol solutions of 8 chicory herb samples had the absorption maximum at the wavelength range from 326 to 330 nm, which was typical for phenolic acids. Chlorogenic acid was chosen as a marker substance for the quantitative determination by direct spectrophotometry. The value of the specific absorbance (556.21(λ=327 nm)) of chlorogenic acid in the concentration of 10.08 µg/ml in ethanol 50% was determined. The total amount of hydroxycinnamic acids was found to be 1.87% for the sample of 2017, for the samples of 2018 in the range of 4.00–6.61%. The method proposed is acceptable for standardization of the medicinal plant raw material.

Content of selenoaminoacids and catechins in Chinese green teas

In this study, famous Zhejiang teas were evaluated as a well-advertised source of selenium. The 25 samples from provinces around China and Asia were purchased in Warsaw tea shops. The speciation analysis of selenium as well as the evaluation of catechin content in water tea infusions was performed using hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS/MS). It turned out that all of tested samples can be a great source of organic selenium species (no traces of inorganic selenium was found), however, Zhejiang teas did not differ much among others. Such a conclusion can also be drawn when comparing the antioxidant capacity of the tested samples, obtained with the application of four methods (Folin–Ciocalteu method, scavenging of the 2,2-diphenyl-1-picrylhydrazyl radical, hydroxyl radical scavenging and cupric reducing ability assay). What is more, no correlation was found between the selenium content and the antioxidant activity of studied teas. The results obtained for the six samples from Zhejiang Province were very varied, which shows that it is very difficult to interpret the results and compare them with the results of other authors.

Determination of the concentration of total phenolic compounds in aged cachaça using two-dimensional fluorescence and mid-infrared spectroscopy

In this work, we investigate alternative quantification methods based on optical spectroscopy and variable selection approach, using as a case study the aging process of cachaça. The cachaça was aged in an Amburana barrel and the samples were analyzed with a traditional analytical method for total phenolic quantification (Folin-Ciocalteu), with 2-D fluorescence and infrared spectroscopy. We applied a methodology based on Ant Colony Optimization to optimize variable selection and model fitting to predict total phenolic content. Our results demonstrated that fluorescence spectroscopy was more sensitive than IR in the quantification of total phenolic compounds for both global and local models, presenting good results (R² superior to 0.979), significantly reducing the number of original variable (1995) for only 4 pairs of Ex/Em. Variable selection combined with spectroscopy reveals potential because this technique eliminates the need for sample preparation and allows the construction of customized sensors for application in the food industry.

Trace elements in ready-to-drink ice tea: Total content, in vitro bioaccessibility and risk assessment

Tea is one of the most consumed non-alcoholic beverages in world and it has been frequently associated to health benefits. Besides its nutrient composition, non-essential trace elements associated with toxic effects may also be present. Ever since food components undergo biotransformation process along gastrointestinal tract after ingestion, it is important to evaluate both total and bioavailable content of trace elements. Therefore, this study aimed to provide comprehensive data concerning the influence of the in vitro digestion on sixteen trace elements present in ready-to-drink ice tea (black, green, mate and white tea). Essential minerals (Co, Cr, Cu, Fe, Mn, Se and Zn) and inorganic contaminants (Al, As, Cd, Li, Ni, Pb, Sb, Sn and Sr) contents were determined by ICP OES after microwave acid digestion. Bioaccessibility evaluation was carried out by simulating the gastric (pepsin) and intestinal juice (pancreatin and bile salts) and bioavailability used Caco-2 cells culture as an intestinal epithelial model. Moreover, tannins were evaluated by UV-VIS spectroscopy. Multivariate analysis allowed classifying ice tea samples in three groups, based on their trace elements profile. Al, Cu, Sr, Mn and Zn bioaccessible fractions corresponded to, approximately, 40-60% of their total content. For Mn, bioaccessibility and bioavailability presented the same pattern (green ice tea > black ice tea > mate ice tea) whilst Sr bioavailability in green tea were 50% higher than in black tea samples.

Viscum album L. homogenizer-assisted and ultrasound-assisted extracts as potential sources of bioactive compounds

Viscum album L. (Mistletoe) is one of the most famous plants in many countries utilized for several purposes. The current study aimed to describe chemical profiles and biological activities of homogenizer-assisted extract (HAE) and ultrasound-assisted extract (UAE)) of V. album parts (leaf, fruits, and seeds). Antioxidant (radical scavenging, reducing power, metal chelation, and phosphomolybdenum assays) and enzyme inhibitory properties (cholinesterases, amylase, glucosidase, and tyrosinase) were selected for biological evaluation. Chemical profiles were studied by HPLC-MS/MS and 32 compounds were identified in the extracts; caffeoylquinic acids and its derivatives, dimethylated flavonoids were the most significant compounds. Generally, the leaf extracts exhibited the best antioxidant and enzyme inhibitory effects in our tests. Multivariate analysis was performed to obtain more information for these data, then strong correlations between total bioactive compounds and tested parameters were observed. The present findings encourage us to further investigate V. album as a potential candidate for pharmaceutical and nutraceutical applications. PRACTICAL APPLICATIONS: Viscum album L. commonly called European mistletoe is a woody perennial shrub growing on coniferous trees with lathery leaves, small flowers, and white berries. It belongs to the Santalaceae R. Br. family from Europe and western/southern Asia. Traditional medicine recognizes mistletoe as a folk remedy to manage inflammation, hypertension, ulcers, and other diseases due to the presence of different bioactive compounds, among them mistletoe lectins and viscotoxins. Recent studies documented the possible therapeutic applications of Viscum extracts in association with cancer's therapy leading to improvements in health and patient's quality of life. Thus, this work gives novel data regarding the phytochemical characterizations and antioxidant/enzymatic inhibitor activities of different types of extracts from seeds, leaves, and fruits of Viscum L. obtained by homogenizer-assisted and ultrasound-assisted techniques, in order to increase the data set of potential applications in medicine.

Effects of Ephedra alata extract on the quality of minced beef meat during refrigerated storage: A chemometric approach

The biopreservative effect of Ephedra alata aqueous extract (EAE), used at 0.156, 0.312 and 0.624%, on minced beef meat was evaluated by microbiological, physicochemical and sensory analyses during storage at 4 °C for 14 days. The results showed that EAE significantly (P < .05) delayed the formation of thiobarbituric acid-reactive substances and carbonyls and reduced the sulfhydryl loss in a dose-dependent manner, indicating that EAE had a protective effect against lipids and protein oxidation. Concomitantly, an increase of redness and loss of lightness and yellowness was observed. Furthermore, two multivariate exploratory techniques, namely Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were applied to all obtained data describing the main characteristics attributed to refrigerated meat samples. During storage time, the used chemometric approaches were useful in discriminating meat samples, and therefore offers an approach to underlay connections between meat quality features. The obtained findings demonstrated the strong potential of EAE as a natural preservative in meat and meat products.

A comparative UPLC-Q-TOF/MS-based metabolomics approach for distinguishing peach (Prunus persica (L.) Batsch) fruit cultivars with varying antioxidant activity

Peaches (Prunus persica (L.) Batsch) are nutritionally and economically important and they are one of the most popular fruits consumed worldwide. Understanding metabolite-caused bioactivity differences among cultivars is essential for designing a peach with enhanced nutritional traits. In this study, we report an untargeted UPLC-Q-TOF/MS-based metabolomics approach for comprehensively discriminating between peaches with different antioxidant activities. Mature fruit from 40 peach cultivars were distinguished using principal component analysis and orthogonal partial least squares discrimination analysis. Seventeen differential metabolites were tentatively identified between peach cultivars with high and low antioxidant potency composite indices, and eight metabolites, including procyanidin C1, procyanidin trimer isomer 1, procyanidin trimer isomer 2, procyanidin B1, procyanidin B2, procyanidin B3, prunus inhibitor b, and phloridzin, were identified as marker compounds responsible for the discrimination of the cultivars base on potential antioxidant activity. Our study highlights the essence and predictive power of metabolomics for detecting small differences and for identifying potential marker metabolites based on their levels and composition in plants exhibiting varying bioactivities. Overall, the variations in the metabolites in peach pulp reflected the diversity in the peach germplasm, and these eight compounds are good candidate markers for future genetic breeding of peach fruit with enhanced antioxidant activity.

Determination of selenium species in beetroot juices

Over the past years, there is an increasing demand for healthy, natural foods. Due to the high content of betalains, beetroots are widely used in the food industry as a natural colorant. In this study, beetroot juices are shown as a great source of selenium compounds. The juices were purchased from a local store and the ecological one was purchased form organic street market. The content of organic selenium species, as well as betalains, were evaluated using hydrophilic interaction liquid chromatography (HILIC) chromatography. The concentrations of selenomethionine (SeMet) and methylselenocysteine (MeSeCys) in analyzed juices were comparable except for juice from ecological cultivation. In that case, the concentration of SeMet is the highest of all studied juices, but simultaneously the concentration of MeSeCys was the lowest one. No traces of major inorganic species of Se, such as Se(IV) and Se(VI) was detected. The reducing power of juices evaluated by Folin-Ciocalteu assay was in range 50.78-166.7 mg GA/L. Juices obtained from beetroot from ecological cultivation showed the highest ability to scavenge the 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals. There was a correlation between the yellow pigment content and the presence of selenocysteine in studied juices.

Selenium in plant foods: speciation analysis, bioavailability, and factors affecting composition

Interest in selenium has been increasing over the past few decades with growing knowledge of its importance to overall health. The ability of several plants to accumulate and transform inorganic selenium forms into its bioactive organic compounds has important implications for human nutrition and health. In this review, we present the studies carried out during the last decade to characterize selenium species produced by different plant foods. Attention is also paid to the effect of selenium treatment on chemical composition and antioxidant properties of plants.

Preparation of soy sauce by walnut meal fermentation: Composition, antioxidant properties, and angiotensin-converting enzyme inhibitory activities

Remaining walnut meal after oil extraction still contains many nutrients. However, these by‐products have not been effectively used. In this study, walnut meal and Aspergillus oryzae (3.042) were used in combination to prepare a soy sauce‐like material with high amino nitrogen content (ANC). The optimal conditions for the preparation of walnut soy sauce (ratio of brine:koji of 1.7:1 for 6 days at 45°C) were determined using response surface experiments (RSE), which showed maximum ANC of 855 mg/100 ml. The results of amino acid analysis indicated that walnut soy sauce had a similar amino acid composition compared with three commercial soy sauces. It contained all the essential amino acids and had a high content of umami amino acids such as Glu and Asp, which may give it a stronger umami taste. Moreover, the crude walnut soy sauce was extracted sequentially using ethyl acetate, n‐butanol, acetone and water, and the total phenols, total flavonoids, reducing sugars, and the peptides of different solvent extracts were measured. Results showed that the total phenolic and flavonoid contents were highest in the ethyl acetate extracts. However, water residue had the highest levels of reducing sugars and peptides. In vitro, the water residue showed the highest antioxidant capacity and angiotensin‐converting enzyme (ACE) inhibitory activity, due to more reducing sugars and peptides. These results indicated that walnut soy sauce may have significant antioxidant and ACE inhibitory activity. The findings provide a scientific basis for developing a replacement for soy sauce and broaden the beneficial application of walnut meal.

The Fruit Malus prunifolia (Malus micromalus Mak.): A Minireview of Current Knowledge of Fruit Composition and Health Benefits

The fruit Malus prunifolia (Malus micromalus Mak.), which belongs to the Rosaceae family, grows mostly in the upper-middle reaches of the Yellow River area. It has long been popular as a fruit commodity and as a natural remedy. Its main biologically active components include vitamin C, phenolics, flavonoids, polysaccharides, and triterpenic acids. Recent phytochemical studies on the fruit have shed some light on its biological activities, such as anticancer, immunomodulatory, antioxidant, immunostimulating, hepatoprotective, and gastrointestinal protective activities. A stronger focus on clinical studies and phytochemical characterization of the fruit will be essential for future research efforts. This minireview could be useful for predicting its other medicinal uses and its potential drug or food interactions, and it could be beneficial for people living in areas where the fruit is endemic and where healthcare resources are scarce.