Fruits of the actinidia genus

Antioxidant Activity and Fatty Acid Profile of Sous-Vide Beef Marinated with Kiwiberry Fruit Pulp: Effects of Level Addition and Refrigerated Storage

The purpose of the study was to determine the antioxidant activity (AA) and fatty acid (FA) profile of sous-vide beef previously marinated in brine with a 10, 20 and 30% addition of kiwiberry (Actinidia arguta cv. 'Ananasnaya') fruit pulp, as well as changes in the parameters studied after 0, 1, 2 and 3 weeks of refrigerated storage in a vacuum package. The FA profile, FRAP (ferric-reducing antioxidant power assay), ABTS (2,2'-azinobis (3-ethylbenzthiazoline-6-acid)), total polyphenols, chlorophylls and carotenoids were also determined in the fruit pulp. Lipid indices for meat were calculated based on the obtained FA profile. The values of FRAP and ABTS of experimental meat products were significantly (p ≤ 0.05) higher than those of control samples but decreased with storage time. The proportion of unsaturated FA in the lipids of sous-vide meat was higher in samples with pulp than in control samples and insignificantly decreased with storage time. Meat marinated with kiwiberry pulp was characterized by a significantly (p ≤ 0.05) higher proportion of ALA (α-linolenic acid) and LA (linoleic acid), considerably affecting the more favorable value of polyunsaturated FA/saturated FA ratio. A troubling finding was the heightened level of palmitic acid (C16:0) in the lipids of beef subjected to 30% kiwiberry pulp, a factor recognized to play a significant role in the development of various diseases. Beef marinated with 20% kiwiberry pulp addition provides greater nutritional and health benefits than other sample variants because of optimal AA and FA profile changes during refrigerated storage.

Transcriptome and metabolome analyses of anthocyanin biosynthesis in post-harvest fruits of a full red-type kiwifruit (Actinidia arguta) 'Jinhongguan'

Anthocyanin is the main component of pigment in red-fleshed kiwifruit. 'Jinhongguan' is a new cultivar of Actinidia arguta with red peel and flesh after harvest. However, the specific types of anthocyanin in the 'Jinhongguan' fruit and its biosynthesis pathways remain largely unknown. Here, the total anthocyanin content in the fruit color conversion process was determined. The results showed that total anthocyanin content increased with the deepening color of the peel and flesh. To identify the genes related to anthocyanin biosynthesis and the types of anthocyanins in the 'Jinhongguan' fruit, a combined analysis of transcriptome and anthocyanin-targeted metabolome was carried out. A total of 5751 common differentially expressed genes (DEGs) at different stages of peel and flesh were identified, of which 2767 were common up-DEGs and 2976 were common down-DEGs. KEGG and GO enrichment analyses showed that the common up-DEGs were significantly enriched in anthocyanin synthesis-related pathways, suggesting some up-DEGs are involved in anthocyanin biosynthesis. In total, 29 metabolites were detected in the flesh by anthocyanin-targeted metabolome. Among these, nine were differential accumulation metabolites (DAMs) in comparison to red flesh vs green flesh. Six DAMs were up-regulated, with five of them were cyanidins. The content of cyanidin-3-O-galactoside was much higher than that of other DAMs, making it the main pigment in 'Jinhongguan'. Moreover, a total of 36 anthocyanin synthesis-related structural genes, 27 MYB transcription factors (TFs), 37 bHLH TFs and 9 WDR TFs were screened from the common DEGs. Correlation analysis of transcriptome and metabolome revealed that 9 structural genes, 6 MYB TFs, 6 bHLH TFs and 1 WDR TF were significantly associated with cyanidin-3-O-galactoside. Further, qRT-PCR analysis demonstrated that structural genes (AaPAL3, Aa4CL3, AaCHS2/3/8/9/11, AaDFR1/2, AaANR1, UFGT3a and UFGT6b) and TFs (MYB108, bHLH30, bHLH94-1 and WD43) play important roles in cyanidin biosynthesis. Overall, this study identified cyanidin-3-O-galactoside as the main anthocyanin type and revealed key candidate genes of red coloration of post-harvest fruit in Actinidia arguta. These findings provided new insights into the color formation mechanism of post-harvest fruit and offered a theoretical basis for color regulation in kiwifruit.

Comparative transcriptomic and plastid development analysis sheds light on the differential carotenoid accumulation in kiwifruit flesh

Carotenoids are colorful lipophilic isoprenoids synthesized in all photosynthetic organisms which play roles in plant growth and development and provide numerous health benefits in the human diet (precursor of Vitamin A). The commercially popular kiwifruits are golden yellow-fleshed (Actinidia chinensis) and green fleshed (A. deliciosa) cultivars which have a high carotenoid concentration. Understanding the molecular mechanisms controlling the synthesis and sequestration of carotenoids in Actinidia species is key to increasing nutritional value of this crop via breeding. In this study we analyzed fruit with varying flesh color from three Actinidia species; orange-fleshed A. valvata (OF), yellow-fleshed A. polygama (YF) and green-fleshed A. arguta (GF). Microscopic analysis revealed that carotenoids accumulated in a crystalline form in YF and OF chromoplasts, with the size of crystals being bigger in OF compared to YF, which also contained globular substructures in the chromoplast. Metabolic profiles were investigated using ultra-performance liquid chromatography (UPLC), which showed that β-carotene was the predominant carotenoid in the OF and YF species, while lutein was the dominant carotenoid in the GF species. Global changes in gene expression were studied between OF and GF (both tetraploid) species using RNA-sequencing which showed higher expression levels of upstream carotenoid biosynthesis-related genes such as DXS, PSY, GGPPS, PDS, ZISO, and ZDS in OF species compared to GF. However, low expression of downstream pathway genes was observed in both species. Pathway regulatory genes (OR and OR-L), plastid morphology related genes (FIBRILLIN), chlorophyll degradation genes (SGR, SGR-L, RCCR, and NYC1) were upregulated in OF species compared to GF. This suggests chlorophyll degradation (primarily in the initial ripening stages) is accompanied by increased carotenoid production and localization in orange flesh tissue, a contrast from green flesh tissue. These results suggest a coordinated change in the carotenoid pathway, as well as changes in plastid type, are responsible for an orange phenotype in certain kiwifruit species.

Kiwifruit's Allergy in Children: What Do We Know?

Kiwifruit allergy is an emerging pathological condition in both general and pediatric populations with a wide range of symptoms linked to variable molecular patterns, justifying systemic and cross-reactions with other allergens (i.e., latex, pollen, and fruit). Skin prick test (SPT), specific serum IgE (Act d 1, Act d 2, Act d 5, Act d 8, and Act d 10) directed against five out of thirteen molecular allergens described in the literature, and oral test challenge with kiwifruit are available for defining diagnosis. The management is similar to that of other food allergies, mostly based on an elimination diet. Although kiwi allergy has been on the rise in recent years, few studies have evaluated the clinical characteristics and methods of investigating this form of allergy. Data collected so far show severe allergic reaction to be more frequent in children compared to adults. Therefore, the aim of this review is to collect the reported clinical features and the available association with specific molecular patterns of recognition to better understand how to manage these patients and improve daily clinical practice.

Cultivar difference characterization of kiwifruit wines on phenolic profiles, volatiles and antioxidant activity

Antioxidant activity and volatiles of kiwifruit wine with different flesh colors were investigated in this study. Green (Guichang and Xuxiang), red (Donghong and Hongyang), and yellow (Jinyan) kiwifruits were analyzed to determine their alcohol content, phenolic profiles, antioxidant activity, and aroma composition. The results showed that Hongyang and Donghong wines had higher antioxidant activity and content of antioxidant substances. Hongyang wine possessed the most abundance of polyphenolic compounds, chlorogenic acid and catechins were the main polyphenols of kiwi wines. The 101 aromatic components were detected, Xuxiang wine possessed 64 aromatic compounds, Donghong and Hongyang wines had the higher esters compositions, 79.87%, and 78.0% respectively. From PCA (Principal Component Analysis), the volatile substances of kiwi wine with the same flesh color were similar. Five kinds of kiwi wines shared 32 kinds of volatile compounds, these compounds may be the core volatiles in kiwi wine. Therefore, the color of kiwi flesh can impact wine flavor, with Hongyang and Donghong kiwis owning red flesh being the most suitable for producing kiwi wine which would be a new milestone to the wine manufactures.

Actinidin diversity: discovery of common and selective substrates for actinidin isoforms and Actinidia cultivars

The actinidin proteinase family has a striking sequence diversity; isoelectric points range from 3.9 to 9.3. The biological drive for this variation is thought to be actinidin's role as a defense-related protein. In this study we map mutations in the primary sequence onto the 3D structure of the protein and show that the region with the highest diversity is close to the substrate binding groove. Non-conservative substitutions in the active site determine substrate preference and therefore create problems for quantification of actinidin activity. Here we use a peptide substrate library to compare two actinidin isoforms, one from the kiwiberry cultivar 'Hortgem Tahi' (Actinidia arguta), and the other from the familiar kiwifruit cultivar 'Hayward' (Actinidia chinensis var. deliciosa). Among 360 octamer substrates we find one substrate (RVAAGSPI) with the useful property of being readily cleaved by all the functionally active actinidins in a set of A. arguta and A. chinensis var. deliciosa isoforms. In addition, we find that two substrates (LPPKSQPP & ILRDKDNT) have the ability to differentiate different isoforms from a single fruit. We compare actinidins from 'Hayward' and A. arguta for their ability to digest the allergenic gluten peptide (PFPQPQLPY) but find the peptide to be indigestible by all sources of actinidin. The ability to inactivate salivary amylase is shown to be a common trait in Actinidia cultivars due to proteolysis by actinidin and is particularly strong in 'Hortgem Tahi'. A mixture of 10% 'Hortgem Tahi' extract with 90% saliva inactivates 100% of amylase activity within 5 minutes. Conceivably, 'Hortgem Tahi' might lower the glycaemic response in a meal rich in cooked starch.

Actinidin in Green and SunGold Kiwifruit Improves Digestion of Alternative Proteins—An In Vitro Investigation

Both Hayward (green) and SunGold (gold) kiwifruit varieties contain a proteolytic enzyme, actinidin, that has been reported to enhance the upper tract digestion of animal proteins. Unlike the other gold varieties, which do not contain any actinidin, the SunGold variety contains significantly higher actinidin activity, but its activity is still much lower than that present in the green (Hayward) fruit. The objective of this study was to determine the effectiveness of actinidin in Hayward and SunGold kiwifruit in digesting alternative proteins, including pea protein, almonds, tofu, and quinoa. The protein sources were digested using a three-stage in vitro oral-gastro-small intestinal digestion model. The findings showed that both kiwifruit extracts enhanced the breakdown (observed through SDS-PAGE) for all the studied protein sources, particularly during gastric digestion, possibly due to higher actinidin activity at gastric pH. The increase in the rate of protein breakdown was probably due to the broader specificity of actinidin compared to pepsin. For many protein sources, most of the intact proteins disappeared within the first few minutes of gastric digestion with added kiwifruit extract. Green kiwifruit extract, due to its higher actinidin activity, had a higher effect on protein breakdown than the SunGold extract. However, for some proteins and under certain digestion conditions, SunGold extract resulted in higher protein breakdown. The latter, in the absence of any digestive enzymes, also led to some protein breakdown during the small intestinal digestion phase, which was not the case for the green kiwifruit extract. The green kiwifruit extract led to the greater breakdown of polypeptide chains of Pru-du 6, a major allergen in almonds. The results, for the first time, suggest that both Hayward and SunGold kiwifruit can lead to improved breakdown and digestion of alternative proteins when consumed as part of a meal; and therefore, have the potential to be used as a digestive aid in population groups looking to achieve faster and greater protein digestion such as athletes, elderly and people with the impaired digestive system.

Bioavailability of Macro- and Microelements in Rats Fed Hypercholesterolemic Diets Containing Actinidia arguta Fruits

The aim of this study was to estimate the influence of different cultivars of Actinidia arguta (kiwiberry) on the bioavailability of mineral elements and to examine the mineral profile of rats fed atherogenic diets enriched with kiwiberries. The following cultivars of Actinidia arguta were used: Bingo, M1, Anna, Weiki, Jumbo, and Geneva. Kiwiberry has recently become popular in the market. It is a precious source of biologically active components, vitamins, and minerals. The livers, spleens, and kidneys were examined for mineral contents using the flame atomic absorption spectroscopy method. The bioavailability of Ca, Mg, Fe, Mn, Zn, and Cu was evaluated. The addition of kiwiberries in atherogenic diets increased the contents of Fe in the rat liver. The bioavailability of Mn, Zn, and Cu, calculated on the basis of the contents in the livers, was significantly decreased in rats fed diets with 5% additional kiwiberries. We supposed that the effect of kiwiberry on the bioavailability of the studied minerals may be related to the diet components of bioactive substances present in fruits (polyphenols, vitamins, dietary fiber, and tannins).

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.

Pseudomonas bijieensis Strain XL17 within the P. corrugata Subgroup Producing 2,4-Diacetylphloroglucinol and Lipopeptides Controls Bacterial Canker and Gray Mold Pathogens of Kiwifruit

Kiwifruit worldwide suffers from the devastating diseases of bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) and gray mold caused by Botrytis cinerea. Here, an endophytic bacterium XL17 isolated from a rape crown gall was screened out for its potent antagonistic activities against Psa and B. cinerea. Strain XL17 and its cell-free culture filtrate (CF) inhibited the growth of Psa and B. cinerea, Psa-associated leaf necrosis, and B. cinerea-associated kiwifruit necrosis. Electron microscopy showed that XL17 CF could damage the cell structures of Psa and B. cinerea. Genome-based taxonomy revealed that strain XL17 belongs to Pseudomonas bijieensis within the P. corrugata subgroup of the P. fluorescens species complex. Among the P. corrugata subgroup containing 31 genomospecies, the presence of the phl operon responsible for the biosynthesis of the phenolic polyketide 2,4-diacetylphloroglucinol (DAPG) and the absence of the lipopeptide/quorum sensing island can serve as the genetic marker for the determination of a plant-protection life style. HPLC detected DAPG in extracts from XL17 CF. MALDI-TOF-MS analysis revealed that strain XL17 produced cyclic lipopeptides of the viscosin family and orfamide family. Together, phenotypic, genomic, and metabolic analyses identified that P. bijieensis XL17 producing DAPG and cyclic lipopeptides can be used to control bacterial canker and gray mold pathogens of kiwifruit.

The effects of kiwifruit dressing on hypertrophic scars in a rabbit ear model

AIMS

Hypertrophic scars show abnormal responses during healing. These scars, associated with dysregulated growth and excessive collagen formation, can have both functional and cosmetic consequences for patients. The present study evaluated the effects of kiwifruit on hypertrophic scars in a rabbit ear model.

METHODS

This study included 13 New Zealand albino rabbits with full thickness wounds down to the cartilage (four wounds per ear; total: 104 scars). Sixteen days after initial wound formation, one ear of each rabbit was treated with daily kiwifruit dressing, while the other ear (control group) was dressed after normal saline irrigation for 10 days. Harvested skin samples were examined for histopathological, morphometric and immunohistochemical results.

RESULTS

In comparison with the control group, early kiwifruit dressing significantly reduced the scar elevation index, fibroblast count and dermal collagen organisation. The ratio of collagen type III to total collagen immunoreactivity, inflammation and dermal capillary count increased significantly in the treated group, compared to the untreated controls.

CONCLUSION

Based on the findings, early kiwifruit dressing improved the histological features of cutaneous wounds in rabbits. Therefore, this approach may be effective in clinical practice.

Osmotic dehydration and convective drying of kiwifruit (Actinidia deliciosa) - The influence of ultrasound on process kinetics and product quality

The aim of this study was to assess the impact of ultrasound on two subsequent processes - initial osmotic dehydration and convective drying of kiwifruit (Actinidia deliciosa). The effect of ultrasound (at a frequency of 25 kHz) was assessed both in terms of process kinetics and product quality. During the study, three different osmotic agents were used - erythritol, sorbitol, and sucrose - in an aqueous solution at a concentration of 50% (w/w). The essential kinetic parameters were analyzed - water loss and increase of dry matter during osmotic dehydration, and evolution of moisture content and temperature of samples during convective drying (drying curves). Product quality was assessed on the basis of color, water activity, and content of relevant bioactive components - polyphenols and carotenoids. It was found that the application of ultrasound during osmotic dehydration resulted in higher water loss and solid gain. This surely results from the phenomena occurring during the propagation of the elastic waves in the liquid medium (mainly related to cavitation) and enhancement of the mass transfer. The use of ultrasound during convective drying also had a positive effect on the kinetics of this process. In most cases, during the ultrasonically assisted drying operations, a significant increase in drying rate was observed, leading to a reduction in drying time. This may be due to the intensification of both heat and mass transfer as a result of the mechanical and thermal effects of ultrasound. The assessment of product quality showed that the use of sugar alcohols was a good alternative to sucrose, and ultrasound-assisted convective drying increased the retention of valuable carotenoids and polyphenols. Moreover, in all dried kiwifruit slices, water activity was below 0.6, which can guarantee the microbiological stability of the tested samples.

Purification and Biochemical Characterization of Cysteine Protease from Baby Kiwi (Actinidia arguta)

Background:

It has recently been reported that the fruit, stems and leaves ofActinidia argutahave various potential health effects including an antioxidant effect, anticancer effect, anti-allergic effect and α-glucosidase inhibitory effect. However, little is known about the biochemical properties of cysteine protease in the fruit juice ofA. arguta.

Methods:

Ion exchange chromatography to purify the cysteine protease from the fruit juice ofA. arguta, and some synthetic substrates to determinate the enzyme activity were used.

Results:

Cysteine protease was purified to homogeneity fromA. argutafruit juice by ion exchange chromatography. The molecular weight of the purified enzyme was calculated to be approximately 25,500 by SDS-PAGE in the presence of β-ME. The enzyme rapidly hydrolyzed the substrate Z-Leu-Arg-MCA and moderately hydrolyzed other substrates including Boc-Val-Leu-Lys-MCA, Z-Val-Val-Arg-MCA and Z-Phe-Arg-MCA. Kinetic parameters for these four substrates were determined. TheKm,Vmax,KcatandKcat/Kmvalues for Z-Leu-Arg-MCA, the most preferentially cleaved by the enzyme, were 100 μM, 63.8 μmoles/mg/min, 27.26 sec-1and 0.2726 sec-1μM-1, respectively. Furthermore, the activity of the enzyme was strongly inhibited by inhibitors including antipain, leupeptin, E-64, E-64c, kinin-free-LMW kininogen and cystatin C. Those biochemical data indicated that the enzyme was a cysteine protease. The amino acid sequence of the first 21 residues of cysteine protease purified fromActinidia argutawas Val1-Leu-Pro-Asp-Tyr5-Val-Asp-Trp-Arg-Ser10-Ala-Gly-Ala-Val-Val15-Asp-Ile-Lys-Ser-Qln20-Gly. This sequence showed high homology to the sequences of actinidin fromAcinidia deliciosa(95.0%) and actinidin fromActinidia eriantha(90%). These three cysteine proteases were thought to be common allied species.

Conclusion:

The biochemical properties of the enzyme purified fromA. argutafruit juice were determined. These basic data are expected to contribute to the maintenance and improvement of human health as well as to the promotion of protein digestion and absorption through its proteolytic functions.

Two-centre comparative experimental study of biparametric MRI at 3.0 T with and without endorectal coil using kiwifruit (Actinidia deliciosa) as a phantom for human prostate

BACKGROUND

Application of an endorectal coil (ERC) for 3.0-T prostate magnetic resonance imaging (MRI) is contentious. We hypothesised that a multicoil phased-array protocol provides T2-weighted images (T2WI) and diffusion-weighted images (DWI) with reduced field-of-view (DWI_reduced) and monoexponential apparent diffusion coefficient (ADC) maps that are technically equivalent with ERC or without ERC (noERC).

METHODS

Axial T2WI (repetition time [TR] 7500 ms, echo time [TE] 98-101 ms) and DWI_reduced (field-of-view 149-179 × 71-73 mm², TR/TE 4500-5500/61-74 ms, b values, 50/800 s/mm²) ERC and noERC images were obtained on identical clinical 3.0-T scanners at two centres and compared for signal-to-noise ratio (SNR) in anterior and posterior outer pericarp (OP) and peripheral placenta (PP) in five green Hayward kiwifruit (Actinidia deliciosa, European Union regulation 543/2011 class 2). Corroboration in 21 patients with benign prostate hyperplasia (negative biopsy, prostate imaging reporting and data system version 2 ≤ 2) involved identical MRI protocols: 10 at site 1, noERC, and 11 at site 2, with ERC. Two-tailed Student's t test was used.

RESULTS

With few exceptions, signal-to-noise ratio (SNR) was similar in kiwifruits and prostates for ERC and noERC. In T2WI, SNR was higher posteriorly in noERC MRI for peripheral zone (PZ) (p < 0.001). In DWI_reduced, SNR was higher posteriorly in ERC-OP (p = 0.013) and ERC-PZ (p = 0.026) for b = 50 s/mm²; noERC-OP (p = 0.044) and ERC-PZ (p = 0.001) for b = 800 s/mm²; and ERC-OP (p = 0.001), noERC-OP (p = 0.001), and ERC-PZ (p = 0.001) for ADC, respectively. Volumes of kiwifruits and prostates were similar (89.2 ± 11.2 versus 90.8 ± 48.5 cm³, p = 0.638-0.920).

CONCLUSIONS

Findings imply that multicoil phased-array 3.0-T prostate MRI with T2WI and DWI_reduced with ADC maps provides equivalent results with and without ERC.

Pectin oligosaccharides from fruit of Actinidia arguta: Structure-activity relationship of prebiotic and antiglycation potentials

Pectin oligosaccharides (POSs) have prebiotic and antiglycation activities in vitro, but the specific structure-activity relationship is unclear. In this study, POSs were obtained by enzymatic and ultrasound-assisted enzymatic degradation of pectin polysaccharide (PPS), respectively. Based on the chemical characterization, the antiglycation in vitro and prebiotic activities of POSs were compared and the structure-activity relationship was studied. The results showed that the antiglycation activity of POSs in vitro was proportional to the galacturonic acid content and GalA:Rha molar ratios except for the low molecular weight POSs (LM-POSs), and inversely proportional to its branching degree, such as Ara:Rha and Gal:Rha molar ratios. In addition, it was also found that the prebiotic activity of POSs was positively correlated with Ara:Rha and Gal:Rha molar ratios in molecule composition and the neutral sugar content, especially galactose and arabinose. The degree of esterification (DE) was less important for both antiglycation and prebiotic activity of POSs. These results provided an important theoretical basis for POSs application in food.

A Comprehensive Review on Kiwifruit Allergy: Pathogenesis, Diagnosis, Management, and Potential Modification of Allergens Through Processing

Kiwifruit is rich in bioactive components including dietary fibers, carbohydrates, natural sugars, vitamins, minerals, omega-3 fatty acids, and antioxidants. These components are beneficial to boost the human immune system and prevent cancer and heart diseases. However, kiwifruit is emerging as one of the most common elicitors of food allergies worldwide. Kiwifruit allergy results from an abnormal immune response to kiwifruit proteins and occur after consuming this fruit. Symptoms range from the oral allergy syndrome (OAS) to the life-threatening anaphylaxis. Thirteen different allergens have been identified in green kiwifruit and, among these allergens, Act d 1, Act d 2, Act d 8, Act d 11, and Act d 12 are defined as the "major allergens." Act d 1 and Act d 2 are ripening-related allergens and are found in abundance in fully ripe kiwifruit. Structures of several kiwifruit allergens may be altered under high temperatures or strong acidic conditions. This review discusses the pathogenesis, clinical features, and diagnosis of kiwifruit allergy and evaluates food processing methods including thermal, ultrasound, and chemical processing which may be used to reduce the allergenicity of kiwifruit. Management and medical treatments for kiwifruit allergy are also summarized.

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.

Phenolic Profiles, Antioxidant Capacities, and Inhibitory Effects on Digestive Enzymes of Different Kiwifruits

In order to obtain high-quality kiwifruits with health-promoting characteristics, physicochemical properties, phenolic profiles, antioxidant capacities, and inhibitory effects on digestive enzymes (pancreatic lipase and α-glucosidase), of fourteen different types of kiwifruit obtained from China were systematically investigated and compared. Noticeable variations in the fruits’ physicochemical properties and phenolic profiles were observed among them. The total phenolic content of Actinidia chinensis cv. Hongshi, A. chinensis cv. Jinshi, and A. chinensis cv. Jinlong were 16.52 ± 0.26 mg GAE/g DW (dry weight), 13.38 ± 0.20 mg GAE/g DW, and 11.02 ± 0.05 mg GAE/g DW, respectively, which were much higher than those of the other tested kiwifruits. According to high performance liquid chromatography (HPLC) analysis, phenolic compounds, including procyanidin B1, procyanidin B2, (−)-epicatechin, chlorogenic acid, gallic acid, and quercetin-3-rhamnoside, were found to be the major compounds in kiwifruits, while procyanidin B1, procyanidin B2, and chlorogenic acid were the most abundant phenolic compounds. Furthermore, all the tested kiwifruits exerted remarkable antioxidant capacities and inhibitory effects on pancreatic lipase and α-glucosidase. Indeed, A. chinensis cv. Hongshi, Actinidia chinensis cv. Jinshi, and Actinidia chinensis cv. Jinlong exhibited much better antioxidant capacities and inhibitory effects on digestive enzymes than those of the other tested kiwifruits. Particularly, A. polygama showed the highest inhibitory activity on α-glucosidase. Therefore, Actinidia chinensis cv. Hongshi, Actinidia chinensis cv. Jinshi, and Actinidia chinensis cv. Jinlong, as well as A. polygama could be important dietary sources of natural antioxidants and natural inhibitors against pancreatic lipase and α-glucosidase, which is helpful for meeting the growing demand for high-quality kiwifruits with health-promoting characteristics in China.

Flavonoid-Rich Extract of Actinidia macrosperma (A Wild Kiwifruit) Inhibits Angiotensin-Converting Enzyme In Vitro

Increasing interest in flavonoids in kiwifruit is due to the health-promoting properties of these bioactives. Inhibition of the angiotensin-converting enzyme (ACE) is one of the main therapeutic targets in controlling hypertension. The present study investigated the ACE inhibitory activity of flavonoid-rich extracts obtained from different kiwifruit genotypes. The flavonoid-rich extracts were prepared from fruits of Actinidia macrosperma, Actinidia deliciosa cv Hayward (Green kiwifruit), and Actinidia chinensis cv Hort 16A (Gold kiwifruit) by steeping the lyophilized fruit samples in 70% aqueous acetone, followed by partitioning the crude extracts with hexane. The composition of each extract was analyzed using ultrahigh-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The ACE inhibitory activity of the fruit extracts was performed using a fluorescence-based biochemical assay. The subclass flavonol was the most abundant group of flavonoids detected in all the extracts tested from three different kiwifruit cultivars. Quercetin-3-O-galactoside, quercetin-3-O-glucoside, quercetin-3-O-rhamnoside, quercetin-3-O-rutinoside, quercetin-3-O-arabinoglucoside, catechin, epigallocatechin gallate, epigallocatechin, chlorogenic, ferulic, isoferulic, and caffeic acid were prominent phenolics found in A. macrosperma kiwifruit. Overall, the flavonoid-rich extract from A. macrosperma showed a significantly (p < 0.05) high percentage of inhibition (IC₅₀ = 0.49 mg/mL), and enzyme kinetic studies suggested that it inhibits ACE activity in vitro. The kiwifruit extracts tested were found to be moderately effective as ACE inhibitors in vitro when compared to the other plant extracts reported in the literature. Further studies should be carried out to identify the active compounds from A. macrosperma and to validate the findings using experimental animal models of hypertension.

Hardy kiwifruit leaves (Actinidia arguta): An extraordinary source of value-added compounds for food industry

The present study reports for the first time the identification and quantification of phenolic compounds, the antioxidant and antimicrobial activities as well as the in vitro radical scavenging activity and intestinal cell effects of A. arguta leaves extracts. Extractions were carried out under water, water:ethanol (50:50) and ethanol. The highest antioxidant activity were obtained in alcoholic extract (IC₅₀ = 53.95 ± 3.09 μg/mL for DPPH; 6628.42 ± 382.49 µmol/mg dry weight basis for FRAP) while the phenolic profile confirmed by HPLC analysis revealed highest amounts of phenolic acids (hydroxycinnamic acid derivatives) and flavonoids (flavan-3-ol and flavonols derivatives). An excellent scavenging activity against reactive oxygen and nitrogen species were determined for all extracts as well as no adverse effects on Caco-2 and HT29-MTX cells in concentrations below 100 μg/mL and 1000 μg/mL, respectively. These results highlight the potentialities of hardy kiwi leaves valorization.

Actinidia arguta extract attenuates inflammasome activation: Potential involvement in NLRP3 ubiquitination

ETHNOPHARMACOLOGICAL RELEVANCE

Actinidia arguta (A. arguta) has been widely used in Asian countries as a traditional medicinal herb to treat inflammation-related diseases, such as gastritis, bronchitis, and arthritis.

AIM OF THE STUDY

The inhibitory effect of A. arguta leaves' extract (AA) on inflammasome activation was investigated to verify its traditional use in treating inflammation-related diseases.

MATERIALS AND METHODS

Bone marrow-derived macrophages (BMDMs) primed by lipopolysaccharide (LPS) were activated by selective inflammasome stimulators, and the effect of AA on inflammasome activation was investigated. A monosodium urate crystal (MSU)-induced peritonitis mouse model was used to study the in vivo efficacy of AA on inflammasome activation.

RESULTS

In the in vitro study, AA regulated NLRP3 ubiquitination and apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization, leading to the inhibition of NLRP3 inflammasome-mediated interleukin (IL)-1β secretion. The inhibitory effect of AA on inflammasome activation in vitro was further confirmed in vivo using an MSU-induced peritonitis mouse model.

CONCLUSION

AA provided scientific evidence, substantiating the traditional claims for its use in the treatment of inflammation and inflammation-mediated metabolic disorders, including gout.

The Nutritional and Health Benefits of Kiwiberry (Actinidia arguta) - a Review

The kiwiberry (Actinidia arguta) is a new product on the market that is enjoying growing consumer acceptance around the world. This widespread interest has created increased demand for identification of the kiwiberry's nutritional health benefits. Containing over 20 essential nutrients and a range of vitamins, the kiwiberry comes near the top of fruits classed as superfoods. It is one of the richest sources of vitamin C with up to 430 mg/100 g fresh weight (FW) and is considered the richest dietary source of myo-inositol (up to 982 mg/100 g FW). The kiwiberry is also one of the richest sources of lutein (up to 0.93 mg/100 g FW) in commonly consumed fruit. Furthermore, containing up to 1301.1 mg/100 g FW phenolics and significant amounts of the essential minerals of potassium, calcium and zinc, the kiwiberry rates very highly as a 'healthy food'. The type and number of this fruit's medicinally promising nutrients have motivated ongoing investigations into its antioxidant, anti-tumour and anti-inflammatory properties. Early research has pointed to the kiwiberry being a very promising treatment for some cancers and health issues involving the gastrointestinal system, hypercholesterolemia and certain cancers. A pharmaceutical composition of A. arguta, A. kolomikta, and A. polygama extracts has already been registered for the prevention and treatment of some immune (inflammatory) mediated diseases, as well as the treatment of some non-allergic inflammatory diseases. This paper reviews and highlights the limited nutritional and therapeutic information currently available on the kiwiberry, a minor fruit possessing such major properties.

Putative mechanisms of kiwifruit on maintenance of normal gastrointestinal function

Kiwifruits are recognized as providing relief from constipation and symptoms of constipation-predominant irritable bowel syndrome (IBS-C). However, the underlying mechanisms, specifically in regards to gastrointestinal transit time and motility, are still not completely understood. This review provides an overview on the physiological and pathophysiological processes underlying constipation and IBS-C, the composition of kiwifruit, and recent advances in the research of kiwifruit and abdominal comfort. In addition, gaps in the research are highlighted and scientific studies of other foods with known effects on the gastrointestinal tract are consulted to find likely mechanisms of action. While the effects of kiwifruit fiber are well documented, observed increases in gastrointestinal motility caused by kiwifruit are not fully characterized. There are a number of identified mechanisms that may be activated by kiwifruit compounds, such as the induction of motility via protease-activated signaling, modulation of microflora, changes in colonic methane status, bile flux, or mediation of inflammatory processes.

Kiwi fruit (Actinidia deliciosa) ameliorates gentamicin-induced nephrotoxicity in albino mice via the activation of Nrf2 and the inhibition of NF-κB (Kiwi & gentamicin-induced nephrotoxicity)

Gentamicin is a potent aminoglycoside antibiotic, but the risk of nephrotoxicity limits its prolonged use. The toxicity of gentamicin is believed to result from oxidative stress, a condition that could be counteracted by dietary antioxidants. This study determines the possible renoprotective effects of kiwifruit against the pathophysiological and ultrastructural alterations induced by gentamicin. Mice were intraperitoneally injected with gentamicin (100mg/kg body weight) for eight consecutive days, and kiwi juice was administered for 8days, either concomitant to or after gentamicin injection. Gentamicin caused nephrotoxicity evidenced by the significant elevation of serum creatinine and blood urea nitrogen levels, along with significant reduction of serum sodium and potassium ions, compared to normal controls. This was associated with proximal tubular necrosis, lysosomal accumulation and mitochondrial alterations, together with glomerular atrophy, mesangial hypercellularity, and inflammatory cell infiltration. Moreover, immunohistochemical results pointed to the relevant role of Nrf2 and NF-κB in gentamicin-induced nephrotoxicity. Kiwi administration, especially when given after gentamicin injection, significantly ameliorated gentamicin-induced pathophysiological alterations, increased the nuclear immunoreactivity of Nrf2 and decreased that of NF-κB. In short, kiwi fruit shows a promising role as a nephroprotective agent against gentamicin-induced nephrotoxicity via attenuating oxidative stress, inflammation and cell death.

Everyman's prostate phantom: kiwi-fruit substitute for human prostates at magnetic resonance imaging, diffusion-weighted imaging and magnetic resonance spectroscopy

OBJECTIVES

To apply an easy-to-assemble phantom substitute for human prostates in T2-weighted magnetic resonance imaging (T2WI), diffusion-weighted imaging (DWI) and 3D magnetic resonance spectroscopy (MRS).

METHODS

Kiwi fruit were fixed with gel hot and cold compress packs on two plastic nursery pots, separated by a plastic plate, and submerged in tap water inside a 1-L open-spout plastic watering can for T2WI (TR/TE 7500/101 ms), DWI (5500/61 ms, ADC b50-800 s/mm² map) and MRS (940/145 ms) at 3.0 T, with phased array surface coils. One green kiwi fruit was additionally examined with an endorectal coil. Retrospective comparison with benign peripheral zone (PZ) and transitional zone (TZ) of prostate (n = 5), Gleason 6-7a prostate cancer (n = 8) and Gleason 7b-9 prostate cancer (n = 7) validated the phantom.

RESULTS

Mean contrast between central placenta (CP) and outer pericarp (OP, 0.346-0.349) or peripheral placenta (PP, 0.364-0.393) of kiwi fruit was similar to Gleason 7b-9 prostate cancer and PZ (0.308) in T2WI. ADC values of OP and PP (1.27 ± 0.07-1.37 ± 0.08 mm²/s × 10^-3) resembled PZ and TZ (1.39 ± 0.17-1.60 ± 0.24 mm²/s × 10^-3), while CP (0.91 ± 0.14-0.99 ± 0.10 mm²/s × 10^-3) resembled Gleason 7b-9 prostate cancer (1.00 ± 0.25 mm²/s × 10^-3). MR spectra showed peaks of citrate and myo-inositol in kiwi fruit, and citrate and "choline+creatine" in prostates. The phantom worked with an endorectal coil, too.

CONCLUSIONS

The kiwi fruit phantom reproducibly showed zones similar to PZ, TZ and cancer in human prostates in T2WI and DWI and two metabolite peaks in MRS and appears suitable to compare different MR protocols, coil systems and scanners.

KEY POINTS

• Kiwi fruit appear suitable as phantoms for human prostate in MR examinations. • Kiwi fruit show zonal anatomy like human prostates in T2-weighted MRI and DWI. • MR spectroscopy reliably shows peaks in kiwi fruit (citrate/inositol) and human prostates (citrate/choline+creatine). • The kiwi fruit phantom works both with and without an endorectal coil. • EU regulation No. 543/2011 specifies physical and biochemical properties of kiwi fruit.

Kiwifruit Allergy in Children: Characterization of Main Allergens and Patterns of Recognition

Kiwifruit allergy has been described mostly in the adult population, but immunoglobulin (Ig)E-mediated allergic reactions to kiwifruit appear to be occurring more frequently in children. To date, 13 allergens from kiwifruit have been identified. Our aim was to identify kiwifruit allergens in a kiwifruit allergic-pediatric population, describing clinical manifestations and patterns of recognition. Twenty-four children were included. Diagnosis of kiwifruit allergy was based on compatible clinical manifestations and demonstration of specific IgE by skin prick test (SPT) and/or serum-specific IgE determination. SDS-PAGE and immunoblotting were performed with kiwifruit extract, and proteins of interest were further analyzed by mass spectrometry/mass spectrometry. For component-resolved in vitro diagnosis, sera of kiwifruit-allergic patients were analyzed by an allergen microarray assay. Act d 1 and Act d 2 were bound by IgE from 15 of 24 children. Two children with systemic manifestations recognized a protein of 15 kDa, homologous to Act d 5. Act d 1 was the allergen with the highest frequency of recognition on microarray chip, followed by Act d 2 and Act d 8. Kiwifruit allergic children develop systemic reactions most frequently following ingestion compared to adults. Act d 1 and Act d 2 are major allergens in the pediatric age group.

Hypoglycemic and antioxidant effects of Daraesoon (Actinidia arguta shoot) in animal models of diabetes mellitus

BACKGROUND/OBJECTIVES

The primary objective of the treatment of diabetes mellitus is the attainment of glycemic control. Hyperglycemia increases oxidative stress which contributes to the progression of diabetic complications. Thus, the purpose of this study was to investigate the hypoglycemic and antioxidant effects of Daraesoon (Actinidia arguta shoot) in animal models of diabetes mellitus.

MATERIALS/METHODS

Rats with streptozotocin-induced diabetes received an oral administration of a starch solution (1 g/kg) either with or without a 70% ethanol extract of Daraesoon (400 mg/kg) or acarbose (40 mg/kg) after an overnight fast and their postprandial blood glucose levels were measured. Five-week-old C57BL/6J mice were fed either a basal or high-fat/high-sucrose (HFHS) diet with or without Daraesoon extract (0.4%) or acarbose (0.04%) for 12 weeks after 1 week of adaptation to determine the effects of the chronic consumption of Daraesoon on fasting hyperglycemia and antioxidant status.

RESULTS

Compared to the control group, rats that received Daraesoon extract (400 mg/kg) or acarbose (40 mg/kg) exhibited a significant reduction in the area under the postprandial glucose response curve after the oral ingestion of starch. Additionally, the long-term consumption of Daraesoon extract or acarbose significantly decreased serum glucose and insulin levels as well as small intestinal maltase activity in HFHS-fed mice. Furthermore, the consumption of Daraesoon extract significantly reduced thiobarbituric acid reactive substances and increased glutathione levels in the livers of HFHS-fed mice compared to HFHS-fed mice that did not ingest Daraesoon.

CONCLUSIONS

Daraesoon effectively suppressed postprandial hyperglycemia via the inhibition of α-glucosidase in STZ-induced diabetic rats. Chronic consumption of Daraesoon alleviated fasting hyperglycemia and oxidative stress in mice fed a HFHS diet.

Do sun- versus shade-grown kiwifruits perform differently upon storage? An overview of fruit maturity and nutraceutical properties of whole and fresh-cut produce

Fresh-cut produce represents a good method to save about 25% of the kiwifruit not useful to meet the fresh fruit-marketing standard due to improper size and shape. For that reason, fresh-cut kiwifruit has been extensively studied. However, the comprehension of the influence of some aspects of cultivation might further increase the shelf life as well as the nutritional values of that fruit. This study explored the hypothesis that kiwifruits grown fully exposed to sunlight or partially shaded differently perform upon storage as whole fruit and as minimally processed produce. Flesh firmness (FF), total solids soluble (SSC), ascorbate (AAT), flavonoids (TFO), and phenols (TF) contents were evaluated in sliced and whole fruit upon 3 days of storage at 4 °C after 75 days of cold chamber storage at 0 °C. The activities of two enzymes related to the softening process, polygalacturonase (PG) and pectinmethylesterase (PME), were evaluated as well. FF and SSC were constitutively higher in sun-exposed fruit, and those characteristics remained higher during the storage as whole fruit. Greater constitutive content of AAT, TFO, and TP was found in sun-exposed whole fruit, although after cutting the reduction in their content was significantly lower in shaded fruits. PME and PG activities were higher only in whole shaded fruits, whereas no relevant differences occurred after cutting. In summary, sun-exposed fruits were more suitable for the fresh-fruit market, whereas the shaded counterpart displayed a good predisposition for use as fresh-cut produce, maintaining similar fruit maturity properties but higher nutraceutical values when sliced than fruit grown under full sun.

Kiwifruit: our daily prescription for health

Kiwifruit are unequalled, compared with other commonly consumed fruit, for their nutrient density, health benefits, and consumer appeal. Research into their health benefits has focussed on the cultivars Actinidia deliciosa 'Hayward' (green kiwifruit) and Actinidia chinensis 'Hort 16A', ZESPRI(®) (gold kiwifruit). Compared with other commonly consumed fruit, both green and gold kiwifruit are exceptionally high in vitamins C, E, K, folate, carotenoids, potassium, fibre, and phytochemicals acting in synergy to achieve multiple health benefits. Kiwifruit, as part of a healthy diet, may increase high-density lipoprotein cholesterol, and decrease triglycerides, platelet aggregation, and elevated blood pressure. Consuming gold kiwifruit with iron-rich meals improves poor iron status, and green kiwifruit aids digestion and laxation. As a rich source of antioxidants, they may protect the body from endogenous oxidative damage. Kiwifruit may support immune function and reduce the incidence and severity of cold or flu-like illness in at-risk groups such as older adults and children. However, kiwifruit are allergenic, and although symptoms in most susceptible individuals are mild, severe reactions have been reported. While many research gaps remain, kiwifruit with their multiple health benefits have the potential to become part of our "daily prescription for health."