Antioxidant potential of phytochemicals in pumpkin varieties belonging to Cucurbita moschata and Cucurbita pepo species

Chemical composition and biological activities of Cucurbita okeechobeensis extracts from its aerial parts, seeds, and fruit shells

The Cucurbita genus has been widely used in traditional medicinal systems across different countries. In this study, we aimed to investigate the chemical composition, antioxidant properties, enzyme inhibitory, and cytotoxic effects of methanol and aqueous extracts obtained from the aerial parts, seeds, and fruit shells of Cucurbita okeechobeensis. Antioxidant properties were assessed using various chemical methods, including radical quenching (DPPH and ABTS), reducing power (CUPRAC and FRAP), metal chelation, and phosphomolybdenum assays. The extracts' enzyme inhibitory effects were tested against cholinesterase, amylase, glucosidase, and tyrosinase, whereas different cancer cell lines were used for the cytotoxicity study. The chemical composition, evaluated by HPLC-ESI-MSn, showed that the most abundant compounds were flavonoids (mainly quercetin glycosides) followed by phenolic acids (mostly caffeic acid derivatives). The aerial parts displayed stronger antioxidant ability than the seed and fruit shells, in agreement with the highest content in phytochemicals. In addition, the methanol extracts presented the highest bioactivity and content in phytochemicals; among them, the extract of the aerial part exhibited significant cytotoxic effects on cancer cell lines and induced apoptosis. Overall, our results suggest that C. okeechobeensis is a valuable source of bioactive compounds for the pharmaceutical and nutraceutical industries.

Antioxidant Capacity of Carotenoid Extracts from the Haloarchaeon Halorhabdus utahensis

Herein, we report on the production, characterization, and antioxidant power assessment of carotenoids from the haloarchaeon Halorhabdus utahensis. It was grown at 37 °C and 180 rpm agitation in halobacteria medium supplemented with glucose, fructose, and xylose, each at concentrations of 0.2%, 1%, and 2%, and the carotenoid yield and composition were investigated. The microorganism produced the carotenoids under all the conditions tested, and their amount followed the order glucose < xylose < fructose. The highest yield was achieved in 2% fructose growth medium with 550.60 ± 7.91 μg/g dry cell and 2428.15 ± 49.33 μg/L. Separation and identification of the carotenoids were performed by RP-HPLC and HPLC/APCI-ITMSn. Bacterioruberin was the main carotenoid detected and accounted for 60.6%, 56.4%, and 58.9% in 2% glucose, 1% xylose, and 2% fructose extracts, respectively. Several geometric isomers of bacterioruberin were distinguished, and representatives of monoanhydrobacterioruberin, and bisanhydrobacterioruberin were also detected. The assignment to cis-isomers was attempted through analysis of the UV/Vis spectra, intensity of cis peaks, and spectral fine structures. The extracts exhibited superoxide scavenging activity higher than butylhydroxytoluene, ascorbic acid, and Trolox, selected as antioxidant references. The anti-hyaluronidase capacity was investigated, and the 2% fructose extract showed the highest activity reaching 90% enzyme inhibition with 1.5 μg. The overall data confirm that Hrd. utahensis can be regarded as an interesting source of antioxidants that can find applications in the food and cosmetic sectors.

The Antioxidant Properties of Selected Varieties of Pumpkin Fortified with Iodine in the Form of Potassium Iodide and Potassium Iodate

This study aimed to investigate the use of selected pumpkin varieties as carriers of potassium iodide (KI) and potassium iodate (KIO₃) at different concentrations (2.3, 0.23, and 0.023 mg/100 g). It was hypothesized that the concentrations and form of iodine fortification in pumpkins affect the antioxidant activity of pumpkins. The results showed a high recovery of the introduced iodine in all pumpkin varieties after drying, as well as high iodine stability during storage, especially for KIO₃. However, statistical analysis confirmed a relationship between the forms and concentration of iodine and the ABTS cation radical and the DPPH radical test results. In the systems with iodine concentration at 0.023 and 0.23 mg/100 g, the antioxidant activity did not change. However, for all pumpkin varieties fortified with a KIO₃ concentration at 3.9 mg/100 g (2.3 mg/100 g of iodine), a statistically significant decrease in free-radical scavenging was confirmed. Therefore, for maximum effectiveness in pumpkin's free-radical scavenging indices, it is suggested to introduce iodine in the form of KI and KIO₃, but in controlled concentrations. However, KIO₃ should be added at a maximum amount of 0.39 mg/100 g.

Evaluation of Antidiabetic and Antioxidant Activities of Fruit Pulp Extracts of Cucurbita moschata Duchesne and Cucurbita maxima Duchesne

Objective

To evaluate and compare the antidiabetic and antioxidant activities of fruit pulp extracts from Cucurbita moschata (PCMOS) and Cucurbita maxima (PCMAX).

Methods

The antidiabetic activity was carried out in vivo by orally and daily giving the extracts at a dose of 500 mg/kg·b.w. to the streptozotocin-induced diabetic male albino Wistar rats for six weeks. After the period of administration, blood glucose levels, body weight, serum insulin, morphology of islets of Langerhans, biochemical parameters, and haematological values of the rats were determined. Meanwhile, the antioxidant activity was carried out in vitro by determination of total phenolic and flavonoid contents, DPPH radical scavenging activity, and ferric reducing antioxidant power.

Results

PCMAX significantly (p < 0.05) reduced blood glucose levels but increased the body weight, serum insulin levels, size and number of islets of Langerhans, and β-cell number of the treated diabetic rats more than PCMOS did. However, they did not alter biochemical parameters and haematological values of the treated diabetic rats. PCMAX possessed total phenolic and flavonoid contents and showed DPPH scavenging and FRAP reducing antioxidant power more significantly (p < 0.05) than PCMOS.

Conclusions

According to the obtained results, it is indicated that PCMOS and PCMAX possess antidiabetic and antioxidant activities. PCMAX possesses more potent antidiabetic and antioxidant activities than PCMOS. These are probably due to PCMAX providing polysaccharide and total phenolic and flavonoid contents more than PCMOS.

Effects of Ginger and Garlic Powders on the Physicochemical and Microbiological Characteristics of Fruit Juices during Storage

Natural preservatives such as garlic and ginger can be added to the formulation of fresh fruit juices to encourage the consumption of health-promoting foods. In this study, the influence of garlic and ginger and the storage conditions on physicochemical and microbiological characteristics of fruit juices were investigated. The fruit juice assortments were produced from apple, apple and pumpkin, and apple and pomegranate and were treated with 0.5 g garlic powder, 0.5 g ginger powder, and 0.25 g mix of garlic and ginger powders. A total of 12 unpasteurized samples were produced, of which 3 were control samples. Samples stored at 20 and 4 °C were analyzed at 0, 3, 6, and 9 days for water activity (aw), pH, titratable acidity (TA), total soluble solids (TSS), electrical conductivity (EC), vitamin C, color parameters, total number of germs, yeasts, and molds, Listeria, Enterobacteriaceae, and Escherichia coli. Results showed that aw, pH, TSS, and vitamin C content decreased during storage of fruit juice samples, while TA increased. The lowest increase in total number of aerobic mesophilic germs was determined for the apple and pumpkin juice with garlic and ginger and apple juice with garlic.

The Total Dietary Antioxidant Capacity, Its Seasonal Variability, and Dietary Sources in Cardiovascular Patients

The favourable role of dietary antioxidants in cardiovascular diseases (CVDs) and protection from them is widely discussed, and total dietary antioxidant capacity (TAOX) is perceived as a diet-quality marker. Data concerning TAOX and its dietary sources related to seasonal variability are limited. We aimed to analyse the TAOXs, seasonal variability, and sources in the daily diets of CVD patients. A total of 143 subjects (82 men, 61 women) since CVD problems were studied. Seasonal recalls were collected regarding dietary sources of antioxidant compounds in spring, summer, autumn, and winter. A food frequency questionnaire was used. The total dietary antioxidant capacity (in μmolTE/day) was calculated for each season. The primary sources of antioxidants in cardiovascular patients' diets were drinks (33%), fruits (28%), vegetables (16%), and black tea (14%). The TAOXs of CVD patients' diets significantly depended on the season (p < 0.001) and were highest in the summer and lowest in the spring. This seasonal variation in consumption was noted. Our findings suggest that a diet characterised with a TAOX might be subjected to fluctuations between seasons. We suggest considering modifications in the dietary recommendations for cardiovascular patients with a low antioxidant capacity between seasons.

Phenolic compounds and antioxidant activity in Cucurbita ficifolia fruits, an underrated fruit

The fruits and seeds of Cucurbita ficifolia Bouché are sources of minerals, vitamins, and functional compounds with nutraceutical and preventive potential against cardiovascular diseases and diseases derived from eating disorders. C. ficifolia is native from Mesoamerica and is currently cultivated in temperate zones from Mexico to South America and Asia. This study evaluated the fruit mesocarps of C. ficifolia for physicochemical parameters, antioxidant activity, and phenolic compound contents in a collection of farmers' landraces. Germplasm is cultivated by traditional farmers in the temperate zones of two municipalities from Oaxaca, Mexico. The results show that the content of soluble solid contents (SSC), pH, total sugars (TS), and flavonoids are influenced by the fruit geographical origin (municipalities) and implicitly by their agroecological cultivation conditions (Huamelúlpam: SSC = 6.22 °Brix, pH = 5.44, TS = 0.52 mg G g-1, flavonoids = 1.24 mg CE g-1; Yanhuitlán: SSC = 6.69, pH = 5.33, TS = 0.55, flavonoids = 1.30). Among populations preserved by traditional farmers, significant differences, and wide variability were found for all parameters evaluated (Huamelúlpam: SSC = 4.9-7.3, pH = 5.5-5.8, TS = 0.4-0.7, protein = 5.8-11.4, polyphenols = 1.9-4.8, flavonoids = 1.0-1.5, DPPH = 4.3-10.6, and FRAP = 4.8-11.8; Yanhuitlán: SSC = 4.3-8.9, pH = 4.8-5.6, TS = 0.4-0.7, protein = 5.0-15.3, polyphenols = 1.9-4.9, flavonoids = 0.8-1.9, DPPH = 5.3-10.5, and FRAP = 4.5-12.6). Eight compounds were identified by UPLC-MS: L-phenylalanine, an amino acid that is regularly associated with proteins; vanillin, a phenolic aldehyde with its functional groups including aldehyde, hydroxyl, and ether; and six phenolic acids: 4-hydroxybenzoic acid, 4-hydroxyphenylacetic acid, vanillic acid, 4-coumaric acid, ferulic acid, and salicylic acid, all with potential health effects. The C. ficifolia fruit mesocarp has bioactive compounds with high antioxidant activity with the potential to both improve diet and to obtain other benefits against nontransmissible diseases derived from food and its associated risk factors.

Isoflavone and Antioxidant of Instant Cream Soup Made from Pumpkin and Tempeh and Their Active Compound in Ovariohysterectomy Rat-Induced Alzheimer’s Disease

Menopause period associated with brain function disorders can caused by decreasing estradiol levels and increasing oxidative stress in the body. Antioxidant agents are required to balance oxidative stress in the body. Instant cream soup made from pumpkin and tempeh is a supplementary food containing isoflavone and antioxidant agents. This study is aimed at analyzing the content of antioxidant level and isoflavones (genistein and daidzein) in instant cream soup and their effect on ovariohysterectomy (OVx) rats. Instant pumpkin cream soup with and without tempeh were subjected to isoflavone content and antioxidant analysis. Serum estradiol was analyzed using enzyme-linked immunosorbent assay. Liver concentration of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) were measured by spectrophotometric methods. The study showed that the isoflavone content (genistein 370.86 g/100 g, daidzein 185.61 g/100 g) was only present in the pumpkin instant cream soup with tempeh (IPTS). IPTS has higher antioxidant levels (134.25 mg AEAC/100 g) than instant pumpkin cream soup without tempeh (IPS). In vivo study, experimental rats showed that OVx increased malondialdehyde (MDA) levels up to 5.85-6.07 nmol mL-1 as compared to control (4.47 nmol mL-1). Moreover, instant pumpkin cream soup with tempeh treatments significantly increased serum estradiol levels (2.37–3.63 μg) and superoxide dismutase (SOD) levels of 497.49-558.89 U mL-1. This study concluded that instant pumpkin cream soup and tempeh contained isoflavone and antioxidant, and it increased estradiol serum and SOD level.

A recent (2009-2021) perspective on sustainable color and textile coloration using natural plant resources

Fast fashion uses an excessive amount of synthetic dyes and chemical reagents in textile production, while a large quantity of fast fashion apparel and clothes go to the landfill, posting environmental safety concerns. Natural dyes not only produce delicate and subdued shades but also have the potential of novel features to achieve active textile substrate with performance properties such as deodorizing, antioxidant, antimicrobial, antifeedant, UV protection, etc. Developing colored textile products with natural colorants in today's market may enhance consumer interest to an even greater extent. Therefore, finding alternative natural degradable dyes has become one of the leading trends in this field. So far, multiple plants and agriculture byproducts have shown promising results in textile dyeing with increasing sustainability and environmental friendliness. There is no doubt in the general acceptance of natural colorants to be utilized as promising substitutes to synthetic dyes for certain categories of textile products, minimizing the negative impact on the health and the ecosystem. With the continuous advancement of natural dyeing research and technology, the dyes will be elaborated even more with finesse, color yield, stability, and colorfastness. This review gives the present status of natural colorants, natural dyeing and color presentation, natural dyeing methods, technique, and performance, mordants and mordanting for natural dyeing, and selection of suitable Agriculture products/byproducts for natural colorants. We hope to provide readers with specific angles on current natural dyeing applications in the textile and apparel industry.

In vitro toxicological assessment and biosensing potential of bioinspired chitosan nanoparticles, selenium nanoparticles, chitosan/selenium nanocomposites, silver nanoparticles and chitosan/silver nanocomposites

Hydrogen peroxide (H₂O₂) is widely used in various industries and biological fields. H₂O₂ rapidly contaminants with water resources and hence simple detection process is highly wanted in various fields. The present study was focused on the biosensing, antimicrobial and embryotoxicity of bioinspired chitosan nanoparticles (Cs NPs), selenium nanoparticles (Se NPs), chitosan/selenium nanocomposites (Cs/Se NCs), silver nanoparticles (Ag NPs) and chitosan/silver nanocomposites (Cs/Ag NCs) synthesized using the aqueous Cucurbita pepo Linn. leaves extract. The physico-chemical properties of as-synthesized nanomaterials were confirmed by various spectroscopic and microscopic techniques. Further, hydrogen peroxide (H₂O₂) sensing properties and their sensitivities were confirmed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) methods, in which Cs/Ag NCs showed pronounced sensing properties. In addition, the mode of antibacterial interaction results clearly demonstrated the effective inhibitory activity of as-prepared Ag NPs and Cs/Ag NCs against Gram negative pathogenic bacteria. The highest embryotoxicity was recorded at 0.19 μg/ml of Ag NPs and 1.56 μg/ml of Se NPs. Intriguingly, the embryo treated with Cs/Se NCs and Cs/Ag NCs significantly reduced the toxicity in the presence of Cs matrix. However, Cs/Se NCs did not show good response in H₂O₂ sensing than the Cs/Ag NCs, implying the biocompatibility of Cs/Ag NCs. Overall, the obtained results clearly suggest that Cs/Ag NCs could be suitable for dual applications such as for the detection of environmental pollutant biosensors and for biomedical research.

Microwave- and Ultrasound-Assisted Extraction of Cucurbita pepo Seeds: A Comparison Study of Antioxidant Activity, Phenolic Profile, and In-Vitro Cells Effects

Nowadays there is a growing demand for nutraceuticals to prevent diseases related to redox imbalances, such as atherosclerosis and diabetes, being crucial to search for new matrixes rich in bioactive compounds. This work aims to characterize the value-added compounds extracted from Curcubita pepo seeds using green methodologies, namely microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE), employing water as an extracting solvent for two ratios (condition 1: 1 mg/20 mL; condition 2: 2.5 mg/20 mL). The extract with the best antioxidant/antiradical activity in FRAP (71.09 μmol FSE/g DW) and DPPH (5.08 mg TE/g DW) assays was MAE condition 1, while MAE condition 2 exhibited the highest activity in the ABTS assay (13.29 mg AAE/g DW) and TPC (16.89 mg GAE/g DW). A remarkable scavenging capacity was observed, particularly for HOCl, with IC50 values ranging from 1.88–13.50 μg/mL. A total of 21 phenolic compounds were identified, being catechin (4.567–7.354 mg/g DW), caffeine (1.147–2.401 mg/g DW) and gallic acid (0.945–1.337 mg/g DW) predominant. No adverse effects were observed on Caco-2 viability after exposure to MAE extracts, while the other conditions led to a slight viability decrease in NSC-34. These results highlighted that the extract from MAE condition 2 is the most promising as a potential nutraceutical ingredient.

Influence of Drying Type of Selected Fermented Vegetables Pomace on the Natural Colorants and Concentration of Lactic Acid Bacteria

Nowadays, foods with probiotic bacteria are valuable and desired, because of their influence on human gut and health. Currently, in the era of zero waste, the food industry is interested in managing its waste. Therefore, the aim of the study was to determine the influence of drying process on the physicochemical properties of fermented vegetable pomace. The work included examining the influence of the lactic acid bacteria (Levilactobacillus brevis, Lactiplantibacillus plantarum, Limosilactobacillus fermentum and its mixture in the ratio 1:1:1) used for vegetable fermentation (beetroot, red pepper, carrot), obtaining pomace from fermented vegetables, and then selection of drying technique using the following methods: convection drying (CD) or freeze-drying (FD) on the physical and chemical properties of pomace. In the obtained pomace and its dried form, dry substance, water activity, color, and active substances such as betalains and carotenoids by spectrophotometric method and also bacteria concentration were evaluated. After fermentation of pomace from the same vegetable, a similar concentration of lactic acid bacteria was found as well as dry substances, color and colorants. Results of physico-chemical properties were related to the used vegetable type. After drying of pomace, it could be seen a high decrease in bacteria and colorant concentration (betalains, carotenoids) independently from drying and vegetable type as well as used starter cultures. The smallest change was observed for spontaneously fermented vegetables compared to those in which the starter culture was used.

Extraction of Carotenoids from Pumpkin Peel and Pulp: Comparison between Innovative Green Extraction Technologies (Ultrasonic and Microwave-Assisted Extractions Using Corn Oil)

Natural pigments improve aesthetic value as well as antioxidant potential of a food product. This study was designed to determine the effects of green extraction techniques on carotenoids, polyphenols and antioxidant activities of pulp and peel of two varieties of pumpkin (Cucurbita maxima). Innovative green extractions (IGE; Ultrasound and Microwave-Assisted Extractions) synergised with corn oil (used as green solvent) were compared with conventional extraction (CE; hexane/isopropyl alcohol; 60:40, v/v). Results showed total carotenoids to be almost double on employing IGE (PM2-UAE-peel = 38.03 ± 4.21; PM4-UAE-peel = 33.78 ± 1.76 µg/g) when compared to conventional extraction (PM2-CE-peel = 19.21 ± 4.39; PM4-CE-peel = 16.21 ± 2.52 µg/g). Polyphenolic contents ranged between 510.69 ± 5.50 and 588.68 ± 7.26 mg GAE/100 g of extract in IGE, compared with conventional extracts (269.50 ± 2.17 to 318.46 ± 6.60 mg GAE/100 g) and percent inhibition of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) ranging between 88.32 ± 1.51 and 93.53 ± 0.30% in IGE when compared with conventional extraction (50.61 ± 1.44 to 57.79 ± 2.09%). Further, oxidative stability of carotenoids extracts from IGE (protection factor = 1.59 ± 0.01 to 1.81 ± 0.05) were found to be significantly higher (p < 0.05) than conventional extracts. Based on results, this study supports the use of innovative green extraction techniques to obtain bioactive pigments like carotenoids. It is anticipated that results generated will find potential applications in food, pharmaceutical and cosmetic industries.

The effect of osmotic dehydration conditions on the calcium content in plant matrice

Osmotic dehydration is used as a pre-treatment before drying. This process can also be used as a method of modulation of the sensory values of plant components and fortifying them with selected components. The aim of this study was to examine the effect of osmotic dehydration as a method of pumpkin flesh 'Melon Yellow' (Cucurbita maxima) fortification with calcium. The studies showed for the first time that by selecting the appropriate process conditions it is possible to significantly increase the level of calcium in plant matrice. The highest calcium content was found in the pumpkin pulp dehydrated in 50% xylitol and inulin solutions with a calcium carbonate (5%), where the process was conducted for 120 min at 30 °C (1,380.4 and 1,328.4 mg Ca/100 g). Therefore, study has shown an innovative application of the osmotic dehydration process for the design of food with health-promoting properties, including for those at risk of osteoporosis.