Influence of Geographical Location of Orchards on Green Kiwifruit Bioactive Components

Valorization of kiwi agricultural waste and industry by-products by recovering bioactive compounds and applications as food additives: A circular economy model

Currently, agricultural production generates large amounts of organic waste, both from the maintenance of farms and crops (agricultural wastes) and from the industrialization of the product (food industry waste). In the case of Actinidia cultivation, agricultural waste groups together leaves, flowers, stems and roots while food industry by-products are represented by discarded fruits, skin and seeds. All these matrices are now underexploited and so, they can be revalued as a natural source of ingredients to be applied in food, cosmetic or pharmaceutical industries. Kiwifruit composition (phenolic compounds, volatile compounds, vitamins, minerals, dietary fiber, etc.) is an outstanding basis, especially for its high content in vitamin C and phenolic compounds. These compounds possess antioxidant, anti-inflammatory or antimicrobial activities, among other beneficial properties for health, but stand out for their digestive enhancement and prebiotic role. Although the biological properties of kiwi fruit have been analyzed, few studies show the high content of compounds with biological functions present in these by-products. Therefore, agricultural and food industry wastes derived from processing kiwi are regarded as useful matrices for the development of innovative applications in the food (pectins, softeners, milk coagulants, and colorants), cosmetic (ecological pigments) and pharmaceutical industry (fortified, functional, nutraceutical, or prebiotic foods). This strategy will provide economic and environmental benefits, turning this industry into a sustainable and environmentally friendly production system, promoting a circular and sustainable economy.

Antioxidative and Anti-Inflammatory Phytochemicals and Related Stable Paramagnetic Species in Different Parts of Dragon Fruit

In this study, we investigated the antioxidant and anti-inflammatory phytochemicals and paramagnetic species in dragon fruit using high-performance liquid chromatography (HPLC) and electron paramagnetic resonance (EPR). HPLC analysis demonstrated that dragon fruit is enriched with bioactive phytochemicals, with significant variations between each part of the fruit. Anthocyanins namely, cyanidin 3-glucoside, delphinidin 3-glucoside, and pelargonidin 3-glucoside were detected in the dragon fruit peel and fresh red pulp. Epicatechin gallate, epigallocatechin, caffeine, and gallic acid were found in the dragon fruit seed. Additionally, 25–100 mg × L⁻¹ of dragon fruit pulp and peel extracts containing enrichment of cyanidin 3-glucoside were found to inhibit the production of reactive oxygen species (ROS), reactive nitrogen species (RNS), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in cell-based studies without exerted cytotoxicity. EPR primarily detected two paramagnetic species in the red samples. These two different radical species were assigned as stable radicals and Mn²⁺ (paramagnetic species) based on the g-values and hyperfine components. In addition, the broad EPR line width of the white peel can be correlated to a unique moiety in dragon fruit. Our EPR and HPLC results provide new insight regarding the phytochemicals and related stable intermediates found in various parts of dragon fruit. Thus, we suggest here that there is the potential to use dragon fruit peel, which contains anthocyanins, as a natural active pharmaceutical ingredient.

Dragon Fruits as a Reservoir of Natural Polyphenolics with Chemopreventive Properties

Dragon fruits are a valued source of bioactive compounds with high potential to become a functional food. The aim of the study was to evaluate and compare the chemopreventive potential and chemical composition of fruits harvested in Thailand and Israel. The amount of different compounds in water and methanol extracts and antioxidant activity was investigated. Moreover, cytotoxic activity against cancer and normal cells of skin, prostate, and gastrointestinal origin was performed, accompanied by anti-inflammatory assay based on NO production in RAW 264.7 macrophage model. Additionally, the quenching properties of polyphenols from fruits were determined by the interaction of the main drug carrier in blood human serum (HSA). The chemometric analysis was used to reveal the relationships between the determined parameters. Dragon fruits harvested in Israel revealed higher antioxidant properties and total content of polyphenols and betacyanins when compared to those from Thailand. The examined fruits of both origins showed significant cytotoxic activity toward colon and prostate cancer cells, with no toxic effect on normal cells, but also no anti-inflammatory effect. Moreover, a high binding ability to HSA was observed for water extracts of dragon fruits. All these predestine dragon fruits are the candidates for the attractive and chemopreventive elements of daily diet.

Comparison of the nutritional properties and biological activities of kiwifruit (Actinidia) and their different forms of products: towards making kiwifruit more nutritious and functional

The nutritional properties and biological activities of kiwifruit and their different products made from same raw kiwifruit were investigated. Compared with the more common Hayward variety, three new kiwifruit varieties, namely Qinmei, Hongyang and Huayou, showed better nutritional properties and biological activities. After processing into different products, the nutritional properties and biological activities of kiwifruit changed substantially but still showed a correlation with the variety's characteristics. Processing kiwifruit into juice, wine and vinegar retained a higher vitamin C and polyphenol content than dried slices and jam and demonstrated better biological activities, while dried slices and jam provided more mineral elements than the three liquid products. In addition, the fermentation products wine and vinegar showed a similar nutritional composition that were present at a higher concentration than in juice, which indicated that fermentation helps in the dissolution of nutrient substances, while the thermal processing products dried slices and jam showed a similar nutritional composition. Consuming original kiwifruit supplies a more comprehensive nutritional composition than from any kiwifruit products.

Green kiwifruit extracts protect motor neurons from death in a spinal muscular atrophy model in Caenorhabditis elegans

Kiwifruit is considered a functional food and a good source of nutraceuticals. Among the possible beneficial effects of kiwifruit species, a neuroprotective activity exerted in rats with learning and memory impairment induced by exposure to different chemicals was reported. We sought to investigate the neuroprotective activities of kiwifruit toward spinal muscular atrophy (SMA). To this purpose, we have used a recently developed Caenorhabditis elegans SMA model, displaying an age-dependent degeneration of motor neurons detected as locomotory defects, disappearance of fluorescent markers, and apoptotic death of targeted neurons. Although an anti-nematode activity is reported for kiwifruit, it has been verified that neither green (Actinidia deliciosa, cultivar Hayward) nor gold (Actinidia chinensis, cultivar Hort 16A) kiwifruit extracts cause detectable effects on wild-type C. elegans growth and life cycle. Conversely, green kiwifruit extracts have a clear effect on the C. elegans SMA model by partially rescuing the degeneration and death of motor neurons and the locomotion impairment. The gold species does not show the same effect. The components responsible for the neuroprotection are macromolecules with a molecular weight higher than 3 kDa, present in the green and not in the yellow kiwifruit. In conclusion, this is the first study reporting a protective activity of green kiwifruit toward motor neurons. In addition, we demonstrate that C. elegans is an animal model suitable to study the biological activities contained in kiwifruit. Therefore, this model can be exploited for future investigations aimed at identifying kiwifruit molecules with potential applications in the field of human health.

A Peptide from Kiwifruit Exerts Anti-Inflammatory Effects in Celiac Disease Mucosa

Objective: Celiac disease is an immune-mediated disease of the intestine triggered by gluten. Gluten elicits, in genetically susceptible individuals, cytokine responses that are then transmitted to the immunocompetent cells. Vegetables and fruit have anti-inflammatory and antioxidant properties with a protective effect on intestinal epithelium. Kiwifruit is known to have beneficial effects on the intestinal tissues, and it is the only plant food containing the peptide kissper, with anti-inflammatory properties. The aim of this study was the evaluation of the kissper effect on the gluten-induced inflammation in celiac disease. Methods: We used an in vitro model of intestinal culture explant from celiac disease patients and non-celiac disease patients, cultured for 24 hours with the toxic gliadin peptide P31-43 and kissper preincubation. Results: Our data showed HLA-DR and TG2 reduction in the celiac disease mucosa pretreated with kissper, as well as a reduction of COX-2 in two patients. No differences we observed for the TGF-b1 and IL-15 levels in supernatants upon kissper pretreatment. Conclusions: The preliminary results suggest that kissper has a potential anti-inflammatory role in celiac disease.

Nutritional properties and biological activities of kiwifruit (Actinidia) and kiwifruit products under simulated gastrointestinal in vitro digestion

BACKGROUND

Kiwifruit is one of the most commercialized fruits on the international market, which has notable high nutritional and medicinal value with many health benefits. In addition to being consumed fresh, numerous kiwifruit products are popular, such as kiwifruit juice, vinegar, dried slices, jam, wine, yogurt, and jelly. Although many studies have described the nutritional properties of kiwifruit, investigations on the nutritional properties of kiwifruit products remain limited, especially for kiwifruit products made from raw kiwifruit.

METHODS

Nutritional properties and biological activities of kiwifruit and kiwifruit products, as well as the digestive and absorption characteristics of their nutritional substances, were investigated.

RESULTS

Kiwifruit, juice, wine, and vinegar were observed to be rich in vitamin C (VC) and polyphenol and exhibited high biological activities, whereas dried kiwifruit slices and jam showed higher amounts of mineral elements. During oral digestion, VC and polyphenol showed similar absorption characteristics, while mineral elements exhibited a number of different trends. A good release rate of all nutritional substances was observed during stomach digestion, while the release rate decreased in serum-available, colon-available, and post-colonic fractions. Eating dried slices and jam supplied high amounts of mineral elements, while eating kiwifruit supplied the most comprehensive nutritional substances. The biological activities detected in raw foodstuffs were much higher than those detected after in vitro digestion. Furthermore, kiwifruit and wine showed the highest biological activities, while dried kiwifruit slices showed the lowest biological activities.

CONCLUSION

These results increased our understanding of the nutritional properties of kiwifruit and its products, providing new information and scientific recommendations to consumers for kiwifruit consumption and to producers for kiwifruit production.

The nutritional and health attributes of kiwifruit: a review

PURPOSE

To describe the nutritional and health attributes of kiwifruit and the benefits relating to improved nutritional status, digestive, immune and metabolic health. The review includes a brief history of green and gold varieties of kiwifruit from an ornamental curiosity from China in the 19th century to a crop of international economic importance in the 21st century; comparative data on their nutritional composition, particularly the high and distinctive amount of vitamin C; and an update on the latest available scientific evidence from well-designed and executed human studies on the multiple beneficial physiological effects. Of particular interest are the digestive benefits for healthy individuals as well as for those with constipation and other gastrointestinal disorders, including symptoms of irritable bowel syndrome. The mechanisms of action behind the gastrointestinal effects, such as changes in faecal (stool) consistency, decrease in transit time and reduction of abdominal discomfort, relate to the water retention capacity of kiwifruit fibre, favourable changes in the human colonic microbial community and primary metabolites, as well as the naturally present proteolytic enzyme actinidin, which aids protein digestion both in the stomach and the small intestine. The effects of kiwifruit on metabolic markers of cardiovascular disease and diabetes are also investigated, including studies on glucose and insulin balance, bodyweight maintenance and energy homeostasis.

CONCLUSIONS

The increased research data and growing consumer awareness of the health benefits of kiwifruit provide logical motivation for their regular consumption as part of a balanced diet. Kiwifruit should be considered as part of a natural and effective dietary strategy to tackle some of the major health and wellness concerns around the world.

Assessment of phenolic contributors to antioxidant activity of new kiwifruit cultivars using cyclic voltammetry combined with HPLC

The phenolics profile of two new kiwifruit cultivars, Zespri® SunGold and Zespri® Sweet Green, were characterized and quantified for the first time using cyclic voltammetry, an electrochemical method, combined with HPLC. Results from the cyclic voltammetry revealed high correlations with those obtained from the spectrophotometry and HPLC methods, providing evidence to support the application of cyclic voltammetry as a rapid method in determining the phenolic profile and reducing power of kiwifruit extracts. Catechol-containing phenolics were identified as the major phenolic sub-class in the skins while flavonoids and phenolic acids were abundant in flesh of the tested cultivars. Epicatechin was the predominant phenolic compound and contributor to antioxidant capacity in all samples. Results also showed that SunGold and Sweet Green (both flesh and skin) exhibited significantly higher phenolic contents and antioxidant activities comparing with the well-established commercial 'Hayward' cultivar, indicating their commercial value and potential applications in food and nutraceuticals.

Pomegranate Cultivars: Identification of the New IgE-Binding Protein Pommaclein and Analysis of Antioxidant Variability

The consumption of pomegranate is increasing as it is considered a health-promoting food. Nevertheless, it can trigger allergic reactions, sometimes severe. The LTP Pun g 1 is the only pomegranate allergen so far reported. Based on preliminary clinical observations, the main aim of this study was the investigation of still unknown allergens contained in this fruit. Pommaclein, a homologue of peamaclein, the peach allergen Pru p 7, was isolated, identified by protein sequencing, and characterized as an IgE-binding protein by different test systems. RP-HPLC protein profiles revealed significant variations of LTP and pommaclein content in the red pulp of selected cultivars and accessions. Conversely, the mesocarp appeared free of proteins and much richer in antioxidants. In conclusion, a new allergen has been identified, and it could contribute to improving allergy diagnosis. The study highlights that pomegranate mesocarp could represent a rich and safe source of nutraceuticals also for allergic subjects.