Anti-Obesity Effect of Different Opuntia stricta var. dillenii's Prickly Pear Tissues and Industrial By-Product Extracts in 3T3-L1 Mature Adipocytes.

Opuntia stricta var. dillenii fruit is a source of phytochemicals, such as betalains and phenolic compounds, which may play essential roles in health promotion. The aim of this research was to study the triglyceride-lowering effect of green extracts, obtained from Opuntia stricta var. dillenii fruit (whole fruit, pulp, peel, and industrial by-products (bagasse)) in 3T3-L1 mature adipocytes. The cells were treated on day 12, for 24 h, after the induction of differentiation with the extracts, at doses of 10, 25, 50, or 100 µg/mL. The expression of genes (PCR-RT) and proteins (Western blot) involved in fatty acid synthesis, fatty acid uptake, triglyceride assembly, and triglyceride mobilisation was determined. The fruit pulp extraction yielded the highest levels of betalains, whereas the peel displayed the greatest concentration of phenolic compounds. The extracts from whole fruit, peel and pulp were effective in reducing triglyceride accumulation at doses of 50 µg/mL or higher. Bagasse did not show this effect. The main mechanisms of action underpinning this outcome encompass a reduction in fatty acids synthesis (de novo lipogenesis), thus limiting their availability for triglyceride formation, alongside an increase in triglyceride mobilisation. However, their reliance is contingent upon the specific Opuntia extract.

In Vitro Screening and Lipid-Lowering Effect of Prickly Pear (Opuntia Ficus-Indica L. Mill.) Fruit Extracts in 3T3-L1 Pre-Adipocytes and Mature Adipocytes.

Opuntia ficus-indica fruits have been widely used due to their nutritional composition and beneficial effects on health, particularly against chronic diseases such as diabetes, obesity, cardiovascular diseases and cancer, among others. In recent years, prickly pear peel and pulp extracts have been characterised, and a high number of bioactive compounds have been identified. This study aimed to analyse the triglyceride-lowering effect of prickly pear peel and pulp extracts obtained from fruits of three varieties (Pelota, Sanguinos, and Colorada) in 3T3-L1 maturing and mature adipocytes. At a concentration of 50 µg/mL, peel extracts from Colorada reduced triglyceride accumulation in pre-adipocytes and mature adipocytes. Additionally, at 25 µg/mL, Pelota peel extract decreased triglyceride content in mature adipocytes. Moreover, maturing pre-adipocytes treated with 50 and 25 µg/mL of Sanguinos pulp extract showed a reduction of triglyceride accumulation. In addition, the lipid-lowering effect of the main individual betalain and phenolic compounds standards were assayed. Piscidic acid and isorhamnetin glycoside (IG2), found in Colorada peel extract, were identified as the bioactive compounds that could contribute more notably to the triglyceride-lowering effect of the extract. Thus, the betalain and phenolic-rich extracts from Opuntia ficus indica fruits may serve as an effective tool in obesity management.

Effect of Ultrasound-Assisted Extraction of Carotenoids from Papaya (Carica papaya L. cv. Sweet Mary) Using Vegetable Oils.

By-products from fruits and are of great interest for their potential use in the food industry due to their high content of bioactive compounds. Herein, we examined the ultrasound-assisted extraction (UAE) of carotenoid and carotenoid esters from papaya pulp and peel using soybean oil and sunflower oil as alternative green solvents. Response surface methodology (RSM) was established to optimize the UAE process. Three independent variables, ultrasonic amplitude (20-60%), time (10-60 min), and co-solvent percentage (ethanol) (5-20%, v/v), were applied. The highest total carotenoid content in the UAE extracts was obtained from papaya pulp extracts (58.7 ± 1.6 and 56.0 ± 1.5 µg carotenoids/g oil) using soybean oil and sunflower oil, respectively (60% amplitude/ 10 min/ 20% ethanol). On the other hand, the highest carotenoid content (52.0 ± 0.9 µg carotenoids/g oil) was obtained from papaya peel using soybean oil applying the UAE process (20% amplitude/ 77 min/ 20% ethanol); a minor content of 39.3 ± 0.5 µg carotenoids/g oil was obtained from papaya peel using sunflower oil at 60% amplitude/ 60 min/ 5% ethanol. Lycopene was the most abundant carotenoid among all individual carotenoids observed in papaya oil extracts, obtaining the highest yields of this carotenoid when papaya pulp and peel were extracted using soybean oil (94% and 81%, respectively) and sunflower oil (95% and 82%, respectively). Great extraction of xanthophyll esters was detected using 20% of ethanol in the vegetable oil extraction solvent (v/v). High correlations (>0.85) was obtained between total carotenoid content and color determination in the UAE oil extracts. UAE vegetable oil extracts enriched with carotenoids from papaya by-products could be useful to formulate new food ingredients based on emulsions with interesting potential health benefits.

Bioaccessibility of Antioxidants in Prickly Pear Fruits Treated with High Hydrostatic Pressure: An Application for Healthier Foods.

High hydrostatic pressure (HHP) is a commercial processing technology which can enhance the health potential of foods by improving the bioaccessibility of their bioactive compounds. Our aim was to study the bioaccessibility and digestive stability of phenolic compounds and betalains in prickly pear fruits (Opuntia ficus-indica L. Mill. var. Pelota and Sanguinos) treated with HHP (100, 350, and 600 MPa; come-up time and 5 min). The effects of HHP on pulps (edible fraction) and peels (sources of potential healthy ingredients) were assessed. In pulps, betanin bioaccessibility increased (+47% to +64%) when treated at 350 MPa/5 min. In HHP-treated pulps, increases in the bioaccessibility of piscidic acid (+67% to +176%) and 4-hydroxybenzoic acid glycoside (+126% to 136%) were also observed. Isorhamnetin glycosides in peels treated at 600 MPa/CUT had higher bioaccessibility (+17% to +126%) than their controls. The effects of HHP on the bioaccessibility of health-promoting compounds are not exclusively governed by extractability increases of antioxidants in the food matrix (direct effects). In this work we found evidence that indirect effects (effects on the food matrix) could also play a role in the increased bioaccessibility of antioxidants in fruits treated with HHP.

Extraction optimization and structural characterization of pectin from persimmon fruit (Diospyros kaki Thunb. var. Rojo brillante).

In this work we have efficiently extracted and characterized pectin from different tissues of astringent (AS) and non-astringent (NAS) persimmon fruits (peel, pulp, whole fruit) for the first time. The highest pectin extraction (≥7.2%) was carried out at 80 °C, 120 min with 1.5% sodium citrate in peel of both AS and NAS persimmon samples. All persimmon pectins showed a molecular weight and galacturonic acid content upper than 328 kDa and 78%, respectively, indicating their suitability as food ingredient. Pectin extracted from AS pulp and peel tissues exhibited an enriched structure in rhamnose and arabinose, whereas the opposite behavior was observed in NAS persimmon whole fruit samples. Remarkably, both pulp tissues (AS and NAS) presented the highest levels of glucose and mannose, non-pectic carbohydrates. In addition, techno-functional assessment (zeta potential, particle size, apparent viscosity, gelation) showed the suitability of the persimmon pectins for a broad range of industrial applications.

In Vitro Antioxidant Capacity of Opuntia spp. Fruits Measured by the LOX-FL Method and its High Sensitivity Towards Betalains.

Current in vitro methodologies neglect or subestimate the contribution of betalains to antioxidant capacity in foods because they do not reflect their in vivo biological mechanisms. In this study, we assessed the sensibility of the lipoxygenase-fluorescein (LOX-FL) method towards betalains, phenolic compounds and ascorbic acid from Opuntia spp. fruits; and (ii) the antioxidant capacity of peel and pulp extracts from Opuntia ficus-indica L. Mill (var. Fresa, Colorada and Blanco) and Opuntia stricta var. Dillenii; by comparing the LOX-FL method to traditional antioxidant methods (ORAC and TEAC). The spectrophotometric monitoring of the LOX-FL reaction avoided interference caused by betalain pigments. Indicaxanthin and betanin showed high antiperoxidative and radical scavenging mechanisms in the LOX-FL assay. O. stricta var. Dillenii tissues the highest antioxidant capacity which correlated with betanin content. ORAC and TEAC antioxidant methods were less sensible towards betalain antioxidant activity. To our knowledge, this is the first time the LOX-FL antioxidant method has been used on betalains and betalain-rich foods.

Carotenoids: Considerations for Their Use in Functional Foods, Nutraceuticals, Nutricosmetics, Supplements, Botanicals, and Novel Foods in the Context of Sustainability, Circular Economy, and Climate Change.

Carotenoids are versatile isoprenoids that are important in food quality and health promotion. There is a need to establish recommended dietary intakes/nutritional reference values for carotenoids. Research on carotenoids in agro-food and health is being propelled by the two multidisciplinary international networks, the Ibero-American Network for the Study of Carotenoids as Functional Foods Ingredients (IBERCAROT; http://www.cyted.org) and the European Network to Advance Carotenoid Research and Applications in Agro-Food and Health (EUROCAROTEN; http://www.eurocaroten.eu). In this review, considerations for their safe and sustainable use in products mostly intended for health promotion are provided. Specifically, information about sources, intakes, and factors affecting bioavailability is summarized. Furthermore, their health-promoting actions and importance in public health in relation to the contribution of reducing the risk of diverse ailments are synthesized. Definitions and regulatory and safety information for carotenoid-containing products are provided. Lastly, recent trends in research in the context of sustainable healthy diets are summarized.

In vitro gastrointestinal stability, bioaccessibility and potential biological activities of betalains and phenolic compounds in cactus berry fruits (Myrtillocactus geometrizans).

Cactus berry (Myrtillocactus geometrizans) is a scarcely studied Mexican wild fruit. These fruits could contribute to reduce the risk of degenerative chronic diseases due to their bioactive profile. The aim of this work was to study the betalains and phenolic profile in cactus berry, their in vitro biological activities and gastrointestinal digestive stability and bioaccessibility. 43 metabolites were identified by HPLC-DAD-ESI-QTOF (8 betaxanthins, 8 betacyanins, 13 flavonoids, 6 phenolic acids). Phyllocactin and Isorhamnetin rhamnosyl-rutinoside (IG2) were the most abundant metabolites (5876 and 396 µg/g dw) which were also bioaccessible (16 and 21%, respectively). Pulps showed higher (p ≤ 0.05) antioxidant activity by the Oxygen Radical Absorbance Capacity (27 mM Trolox equivalents). The anti-hyperglycemic activity was highest (p ≤ 0.05) in peel and pulp tissues (85% α-glucosidase and 8% α-amylase inhibition). An 83% inhibition of hyaluronidase showed high anti-inflammatory activity. Cactus berry fruit should be considered a promising fruit candidate for a sustainable healthy diet.

Release mechanisms of bioactive compounds in fruits submitted to high hydrostatic pressure: A dynamic microstructural analysis based on prickly pear cells.

High hydrostatic pressure (HHP) promotes the release of bioactive compounds from their intracellular compartments making them more bioaccessible. Our aim was to propose a schematic tissue model to explain the release mechanisms of betalains and phenolic compounds in vegetable cells submitted to HHP by analyzing cell microstructure, cell morphology, cell viability and the localization of bioactive compounds in prickly pear fruits. Prickly pear slices were pressurized at 100, 350 and 600 MPa at 20 °C. Chlorenchyma cells (in peels) and parenchyma cells (in pulps) were analyzed by transmission electron microscopy, confocal laser scanning microscopy and optical microscopy. After pressurization, the respiration and ethylene production of processed fruits were measured every 6 h (during storage at 16 °C and 75% RH for 24 h). In chlorenchyma cells, HHP ruptured betalain-storing vesicles in the cytoplasm and possibly increased the activity of endogenous enzymes. Contrarily, HHP released betalains from the vacuoles of parenchyma cells due to breaking of the tonoplast where they presented higher stability. In both tissues, phenolic compounds were released from cell walls with increasing pressure and enhanced by cell wall ultrastructural modifications (100 MPa), rupture (350 MPa) and the rearrangement of microfibrillated cellulose (600 MPa). Prickly pears submitted to HHP presented advanced senescence marked by considerable ethylene increase and the gradual loss of CO2 production after 6 h. Cells were viable at 100 MPa by conserving intact cell membranes and after 24 h their respiration rates presented no significant differences compared to controls therefore indicating the possibility of synthesis of bioactive compound as a response to abiotic stress. We have proposed a new approach for analyzing the effects of HHP and have identified the storing of betalains in vesicles located in the cytoplasm of chlorenchyma cells for the first time. This study is the first to fathom the dynamic morphological changes and release mechanisms of bioactive compounds in vegetable cells subjected to HHP.

Inhibitory potential of prickly pears and their isolated bioactives against digestive enzymes linked to type 2 diabetes and inflammatory response.

BACKGROUND: Prickly pears are potential candidates for the development of low-cost functional foods because they grow with low water requirements in arid regions of the world. They are sources of betalains and phenolic compounds, which have been reported to contribute to human health. The study of the biological activity of different varieties and of their isolated bioactive constitutes is fundamental in the design of functional foods. In this context, our objective is the assessment of the ability of Spanish and Mexican prickly-pear cultivars to inhibit enzymes related to type 2 diabetes and the inflammatory response, and the contribution of their bioactive compounds to their nutra-pharmaceutical potential. RESULTS: Prickly pear peels presented the highest antioxidant activity due to their high isorhamnetin glycoside content. Isorhamnetin glycosides showed significantly higher antioxidant and anti-inflammatory activity than aglycone, particularly isorhamnetin glucosyl-rhamnosyl-pentoside (IG2), which also reported antihyperglycemic activity. Morada, Vigor, and Sanguinos whole fruits exhibited moderate α-amylase inhibition and higher α-glucosidase inhibition, which is ideal for lowering glucose absorption in hyperglycemia management. Sanguinos peels presented the highest anti-inflammatory activity because of their high indicaxanthin content and isorhamnetin glycoside profile. CONCLUSIONS: In the design of prickly pear functional foods, technological processing should prioritize the retention or concentration of these bioactive compounds to preserve (or increase) their natural antioxidant, antihyperglycemic and anti-inflammatory activity. Peels of red and orange varieties should be further evaluated for antioxidant and anti-inflammatory purposes while whole fruits of red and purple varieties could be considered possible candidates for hyperglycemia management. © 2019 Society of Chemical Industry.

Impact of high hydrostatic pressure and thermal treatment on the stability and bioaccessibility of carotenoid and carotenoid esters in astringent persimmon (Diospyros kaki Thunb, var. Rojo Brillante).

The carotenoid and carotenoid ester profile in astringent persimmon (Diospyros kaki Thunb., var. Rojo Brillante) was composed by 13 free xanthophylls, 8 hydrocarbon carotenes and 17 carotenoid esters. The stability and biaoccessibility of these carotenoids was determined by an adaptation of the INFOGEST protocol. Results showed that the stability of persimmon carotenoids ranged from 61 to 74%, depending on the digestion phase, being (all-E)-ß-cryptoxanthin and (all-E)-antheraxanthin 3-O-palmitate the most stable carotenoids. At the final step of the digestion (oral + gastric + duodenal phase), only traces of (all-E)-antheraxanthin, (all-E)-lutein and (all-E)-ß-cryptoxanthin were found in control samples due to the low efficiency of carotenoid micellization, which was affected by the high pectin content naturally present in persimmon tissues. Processing increased the overall carotenoid bioaccessibility to 54% in pressurized samples and to 25% in thermal treated ones. This effect depended on the processing technology as well as on the chemical structure of the carotenoid, being (all-E)-ß-cryptoxanthin and (all-E)-ß-cryptoxanthin laurate the most bioaccessible carotenoids in pressurized samples and (all-E)-ß-cryptoxanthin laurate and (all-E)-antheraxanthin the most bioaccessible ones in pasteurized ones.

Hyaluronidase inhibiting activity and radical scavenging potential of flavonols in processed onion.

The flavonol content and anti-inflammatory and antioxidant activities of onion treated by high-pressure processing (HPP) and HPP combined with freeze-drying and pulverization (HPP-FD-P) were evaluated. Allium cepa L. var. cepa, 'Recas' was treated at T1 (200 MPa/25 °C/5 min), T2 (400 MPa/25 °C/5 min), and T3 (600 MPa/25 °C/5 min). After treatment, HP-treated and untreated samples were frozen (diced onion, HP-treated). Subsequently, part of the diced samples was freeze-dried and pulverized (pulverized onion, HP-treated and freeze-dried). Flavonol content and anti-inflammatory and antioxidant activities (hyaluronidase inhibiting activity, NO(•), ABTS(•+), and DPPH(•) scavenging capacity, ferric reducing antioxidant power, and antioxidative capacity by photochemiluminescence) were measured in nonhydrolyzed and hydrolyzed extracts. Hydrolysis was carried out in order to evaluate the effect of HPP and HPP-FD-P on both anti-inflammatory and antioxidant activities of extracts mainly containing aglycone forms. HPP-FD-P increased quercetin 3,4'-diglucoside, quercetin 4'-glucoside, quercetin 3-glucoside, and isorhamnetin 3,4'-diglucoside extractability. The present study suggests that HPP (especially treatment at 400 MPa) and HPP-FD-P may be of benefit for obtaining functional ingredients from onion, as suggested by increased NO(•) scavenging capacity and maintenance of the antioxidant activity mainly in hydrolyzed extracts.

Changes in the structure and antioxidant properties of onions by high pressure treatment.

Onions have antioxidant properties and they are an important source of bioactive compounds such as phenols. The aim of this work was to study the effect of high hydrostatic pressure (HHP) (100-600 MPa/1-3 min/25 °C) on the microstructure and antioxidant properties of onions (cv. Doux) and its relationship with changes in the extractability of potential health-related compounds. Cryo scanning electron microscopy was used to study the microstructure. Vitamin C, total phenolic content and antioxidant activity (DPPH˙, ABTS˙(+), FRAP) were also analyzed. Tonoplast, plasmalemma and cell walls were affected by the HHP treatment and it favored the diffusion of the cellular content to the intercellular spaces. Vitamin C did not show significant changes, whereas the extracted phenolic content and antioxidant activity increased at pressures of 300 or 600 MPa. Therefore, it could be concluded that HHP produced changes in membrane permeability and disruption of cell walls favoring the release of phenolic compounds from tissue and, in consequence, improving their extractability.

An onion byproduct affects plasma lipids in healthy rats.

Onion may contribute to the health effects associated with high fruit and vegetable consumption. A considerable amount of onion production ends up as waste that might find use in foods. Onion byproduct has not yet been explored for potential health benefits. The aim of this study is to elucidate the safety and potential role of onion byproducts in affecting risk markers of cardiovascular disease (CVD). For that purpose, the effects of an onion byproduct, Allium cepa L. cepa 'Recas' (OBP), and its two derived fractions, an ethanolic extract (OE) and a residue (OR), on the distribution of plasma lipids and on factors affecting cholesterol metabolism in healthy rats have been investigated. The OBP or its fractions did not significantly reduce cholesterol or down-regulate hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) gene expression. The OR even had the effect of increasing plasma triacylglycerides (TAG) and cholesterol in the very low density lipoprotein (VLDL-C) fraction. Neither total bile acids nor total primary or secondary bile acids were significantly affected by feeding rats the OBP or its fractions. Principal component analysis combining all markers revealed that the controls could be completely separated from OBP, OE, and OR groups in the scores plot and also that OE and OR groups were separated. Plasma lipids and bile acid excretion were the discriminating loading factors for separating OE and OR but also contributed to the separation of onion-fed animals and controls. It was concluded that the onion byproduct did not present significant beneficial effects on individual markers related to plasma lipid transport in this healthy rat model but that onion byproduct contains factors with the ability to modulate plasma lipids and lipoprotein levels.

An exploratory NMR nutri-metabonomic investigation reveals dimethyl sulfone as a dietary biomarker for onion intake.

The metabolome following intake of onion by-products is evaluated. Thirty-two rats were fed a diet containing an onion by-product or one of the two derived onion by-product fractions: an ethanol extract and the residue. A 24 hour urine sample was analyzed using (1)H NMR spectroscopy in order to investigate the effects of onion intake on the rat metabolism. Application of interval extended canonical variates analysis (ECVA) proved to be able to distinguish between the metabolomic profiles from rats consuming normal feed and rats fed with an onion diet. Two dietary biomarkers for onion intake were identified as dimethyl sulfone and 3-hydroxyphenylacetic acid. The same two dietary biomarkers were subsequently revealed by interval partial least squares regression (PLS) to be perfect quantitative markers for onion intake. The best PLS calibration model yielded a root mean square error of cross-validation (RMSECV) of 0.97% (w/w) with only 1 latent variable and a squared correlation coefficient of 0.94. This indicates that urine from rats on the by-product diet, the extract diet, and the residue diet all contain the same dietary biomarkers and it is concluded that dimethyl sulfone and 3-hydroxyphenylacetic acid are dietary biomarkers for onion intake. Being able to detect specific dietary biomarkers is highly beneficial in the control of nutritionally enhanced functional foods.

Effects of an onion by-product on bioactivity and safety markers in healthy rats.

Onions are excellent sources of bioactive compounds including fructo-oligosaccharides (FOS) and polyphenols. An onion by-product was characterised in order to be developed as a potentially bioactive food ingredient. Our main aim was to investigate whether the potential health and safety effects of this onion by-product were shared by either of two derived fractions, an extract containing the onion FOS and polyphenols and a residue fraction containing mainly cell wall materials. We report here on the effects of feeding these products on markers of potential toxicity, protective enzymes and gut environment in healthy rats. Rats were fed during 4 weeks with a diet containing the products or a control feed balanced in carbohydrate. The onion by-product and the extract caused anaemia as expected in rodents for Allium products. No other toxicity was observed, including genotoxicity. Glutathione reductase (GR) and glutathione peroxidase (GPx1) activities in erythrocytes increased when rats were fed with the onion extract. Hepatic gene expression of Gr, Gpx1, catalase, 5-aminolevulinate synthase and NAD(P)H:quinone oxidoreductase was not altered in any group of the onion fed rats. By contrast, gamma-glutamate cysteine ligase catalytic subunit gene expression was upregulated but only in rats given the onion residue. The onion by-products as well as the soluble and insoluble fractions had prebiotic effects as evidenced by decreased pH, increased butyrate production and altered gut microbiota enzyme activities. In conclusion, the onion by-products have no in vivo genotoxicity, may support in vivo antioxidative defence and alter the functionality of the rat gut microbiota.