Bioactive compounds and nutritional composition of Swiss chard (Beta vulgaris L. var. cicla and flavescens): a systematic review

Antidiabetic Effect of Combined Leaf Extracts of Portulaca oleracea L., Beta vulgaris L., and Cichorium intybus L. in Streptozotocin-Induced Diabetic Rats

Purslane (P), chard (CHA), and chicory (CHI) leaf extracts are individually and traditionally used in the treatment of diabetes mellitus. Polyphenols, flavonoids, the polyphenolic profile of the extracts, and their antioxidant activity were determined. This study evaluated the antidiabetic activity of combinations of these extracts in streptozotocin-induced diabetic rats. Diabetic groups were administered orally and daily for 40 days with the investigated extracts at 250 mg/kg body weight (b.w.) or metformin (100 mg/kg b.w.) as a drug. Fasting blood glucose, oral glucose tolerance, insulin, and fructosamine were assessed. The combined extracts with high levels of P or CHI exerted potent hypoglycemic activity compared with metformin in addition to the restoration of the histopathological changes in the liver and pancreas of diabetic rats to a near-normal state. Therefore, these combined extracts could be developed as natural drugs for diabetes.

Effect of pre-harvest sanitizer treatments on Listeria survival, sensory quality and bacterial community dynamics on leafy green vegetables grown under commercial conditions

Leafy green vegetables (LGVs) have large surface areas and can be colonized by various microorganisms including pathogens. In this study, we investigated the effect of pre-harvest sanitizer treatments on the survival of inoculated proxy pathogen Listeria innocua ATCC 33090 and the natural microbial community of mizuna, rocket (arugula), red chard and spinach grown under commercial conditions. Electrolyzed water (e-water), peracetic acid (PAA), and 1-bromo-3-chloro-5-dimethylhydantoin (BCDMH) were tested against water controls. We also observed the subsequent sensorial changes of harvested, bagged LGV leaves over a period of 12 days within chill storage alongside the growth, diversity and structure of bacterial populations determined using 16S rRNA gene amplicon sequencing and total viable counts (TVC). Treatment with PAA resulted in the highest reductions of L. innocua (2.4-5.5 log units) compared to the other treatments (0.25-2.5 log units). On day 0 (24 h after sanitizer application), the TVC on sanitizer treated LGVs were significantly reduced compared to water controls, except for rocket. During storage at 4.5 (±0.5)°C sanitisers only hindered microbial growth on LGVs initially and did not influence final bacterial population levels, growth rates or changes in LGV sample colour, decay, odour and texture compared to water controls. Shelf-life was not extended nor was it reduced. The community structure on LGV types differed though a core set of bacterial amplicon sequence variants (ASV) were present across all samples. No significant differences were observed in bacterial diversity between sanitizer treatments, however sanitizer treated LGV samples had initially reduced diversity compared to water treated samples. The bacterial compositions observed at the end point of storage considerably differed from what was observed at initial point owing to the increase in abundance of specific bacterial taxa, mainly Pseudomonas spp., the abundance and growth responses differing between LGV types studied. This study provides a better understanding on the microbiology and sensory impact of pre-harvest applied sanitiser treatments on different LGVs destined for commercial food use.

Nutraceutical Potential of Leafy Vegetables Landraces at Microgreen, Baby, and Adult Stages of Development

Nutraceutical compounds present in leafy vegetables have gained substantial attention due to the health benefits they offer beyond their nutritional value. The biosynthesis, composition, and concentration of these compounds vary widely among leafy vegetables and carry the influence of genetic, agronomic, and environmental factors. Recently, micro-vegetables are gaining importance among consumers worldwide and are used in gastronomy at different development stages. Another tendency is the utilization of local genetic resources as an integral component of agricultural biodiversity crucial for sustainable production. The present study identifies the nutraceutical potential of 10 leafy vegetables at the microgreen, baby, and adult development stages using local genetic resources from the Spanish Vegetable Genebank (CITA, Aragón). Specifically, two landraces for each of the following crops were used: chard (Beta vulgaris), spinach (Spinacia oleracea), lettuce (Lactuca sativa), borage (Borago officinalis), and chicory (Cichorium intybus). The results reinforce the value of traditional local genetics and demonstrate the potential of these leafy vegetables as a source of functional compounds (fatty acids, vitamin C, carotenoids, polyphenols, antioxidant activity, and tocopherols). The observed variability depending on the crop and the developmental stage recommends the necessity of having a varied diet, since each leafy vegetable product offers a unique nutritional profile.

Food Service Kitchen Scraps as a Source of Bioactive Phytochemicals: Disposal Survey, Optimized Extraction, Metabolomic Screening and Chemometric Evaluation

Untargeted metabolomics is a powerful tool with high resolution and the capability to characterize a wide range of bioactive natural products from fruit and vegetable by-products (FVB). Thus, this approach was applied in the study to evaluate the phenolic compounds (PC) by metabolomic screening in five FVB after optimizing their extraction. The total phenolic content and antioxidant activity analyses were able to select the best extractor (SM) and ultrasonication time (US) for each FVB; methanol was used as a control. Although ultrasonication yielded a lower number of PC identifications (84 PC), the US extract was the most efficient in total ionic abundance (+21% and +29% compared to the total PC and SM extracts, respectively). Ultrasonication also increased the phenolic acid (+38%) and flavonoid classes (+19%) extracted compared to SM, while the multivariate analyses showed the control as the most dissimilar sample. FVB extracted from the same parts of the vegetable/fruit showed similarities and papaya seed presented the most atypical profile. The application of the metabolomics approach increased the knowledge of the bioactive potential of the evaluated residues and possibilities of exploring and valorizing the generated extracts.

Effect of the Addition of Different Levels of Chard on the Dough Properties and Physicochemical and Sensory Characteristics of Pan Breads

Background. Chard is a valuable vegetable and is considered a beneficial functional food. Fortification of bread with chard could increase the nutraceutical and functional food consumption. Objective. In this study, we performed a chemical analysis of chard and performed rheological analyses and sensory attribute evaluations of pan breads fortified with 5% and 10% chard powder. Design. The gross chemical composition of chard, some minerals, vitamin C, and total phenolic and flavonoid compounds were estimated. The rheological properties of doughs fortified with 5% and 10% chard powder and the chemical composition and sensory attributes of control, 5% chard and 10% chard pan bread samples were determined. Results. Chard contains carbohydrate, protein, and ash in addition to essential minerals and antioxidants such as vitamin C, phenols, and flavonoids. The chemical composition of 5% chard pan bread was significantly higher in ash and fiber, while the chemical composition of 10% chard pan bread was significantly higher in protein, ash, fiber, and moisture and significantly lower in fat, carbohydrate, and energy level than that of control pan breads. Compared with the control pan bread, the pan bread with increased chard powder content (10%) had significantly increased water absorption percentage, arrival time, dough development, elasticity, and proportional number ratio but significantly decreased stability time, softening degree, and extensibility. Pan bread fortified with 10% chard had the lowest specific volume among the tested breads. Sensory attribute evaluation further showed that increasing the amount of chard to 10% in the bread dough formulation produced lower overall acceptability scores. Conclusions. Pan bread containing 5% chard had better rheological scores and sensory attributes than the other formulations, in addition to good nutritional quality values.

Elevation of brain magnesium with Swiss chard and buckwheat extracts in an animal model of reduced magnesium dietary intake

OBJECTIVES

Inadequate dietary magnesium (Mg) intake is a growing public health concern. Mg is critical for diverse metabolic processes including energy production, macromolecule biosynthesis, and electrolyte homeostasis. Inadequate free Mg²⁺ ion concentration ([Mg²⁺]) in the brain is associated with several neurological and behavioral disorders. Elevating [Mg²⁺]in the brain using oral Mg supplementation has proven to be challenging due to the tight regulation of Mg²⁺ transport to the brain. This study explored the effect of short-term moderate reduction in dietary Mg intake (87% of normal Mg diet for 30 days) on [Mg²⁺] in the cerebrospinal fluid (CSF) ([Mg²⁺]_CSF) and red blood cells (RBCs) ([Mg²⁺]_RBC) in adult male rats. In addition, we investigated the effectiveness of magnesium-rich blend of Swiss chard and buckwheat extracts (SC/BW extract) in increasing brain [Mg²⁺] compared to various Mg salts commonly used as dietary supplements.

METHODS

Animals were assigned to either normal or low Mg diet for 30 - 45 days. Following this, animals maintained on low Mg diet were supplemented with various Mg compounds. [Mg²⁺]_CSF and [Mg²⁺]_RBC were measured at baseline and following Mg administration. Anxiety-like behavior and cognitive function were also evaluated.

RESULTS

The present study showed that a short-term and moderate reduction in Mg dietary intake results in a significant decline in [Mg²⁺]_CSF and [Mg²⁺]_RBC and the emergence of anxiety-like behavior in comparison to animals maintained on normal Mg diet. Supplementation with SC/BW extract significantly elevated [Mg²⁺]_CSF and improved animal performance in the novel object recognition test in comparison with animals maintained on reduced Mg intake and supplemented with various Mg compounds.

DISCUSSION

These observations indicate that brain [Mg²⁺] is more sensitive to a short-term and moderate reduction in Mg dietary intake than previously thought and emphasizes the importance of dietary Mg in replenishing brain Mg²⁺ reserves.

Anthocyanins and Functional Compounds Change in a Third-Generation Snacks Prepared Using Extruded Blue Maize, Black Bean, and Chard: An Optimization

The effect of extrusion cooking on bioactive compounds in third-generation snacks (TGSE) and microwave-expanded snacks (MWSE) prepared using black bean, blue maize, and chard (FBCS) was evaluated. FBCS was extruded at different moisture contents (MC; 22.2–35.7%), extrusion temperatures (ET; 102–142 °C), and screw speeds (SP; 96–171 rpm). Total anthocyanin content (TAC), contents of individual anthocyanins, viz., cyanidin-3-glucoside, malvidin-3-glucoside, pelargonidin-3-glucoside, pelargonidin-3-5-diglucoside, and delphinidin-3-glucoside chloride, total phenolic content (TPC), antioxidant activity (AA), and color parameters were determined. TAC and individual anthocyanin levels increased with the reduction in ET. ET and MC affected the chemical and color properties; increase in ET caused a significant reduction in TPC and AA. Microwave expansion reduced anthocyanin content and AA, and increased TPC. Extrusion under optimal conditions (29% MC, 111 rpm, and 120 °C) generated products with a high retention of functional compounds, with high TAC (41.81%) and TPC (28.23%). Experimental validation of optimized process parameters yielded an average error of 13.73% from the predicted contents of individual anthocyanins. Results suggest that the TGSE of FBCS obtained by combining extrusion and microwave expansion achieved significant retention of bioactive compounds having potential physiological benefits for humans.