Green Kiwifruit Research Articles

Rheological Properties of Green and Gold Kiwifruit Purees at Different Temperatures

Rheological Properties of Green and Gold Kiwifruit Purees at Different Temperatures

‘Mansu’, a Hardy Kiwifruit (Actinidia arguta Planch. et Miq.) Cultivar with Improved Storage Life

In general, the storage life of hardy kiwifruit (Actinidia arguta ) is approximately one month, even in cold storage, which is a limiting factor for its commercialization due to the short marketing period. This short shelf life is in contrast to those of green kiwifruit (A. deliciosa , 6 to 8 months) and gold kiwifruit (A. chinensis , 4 to 6 months). To increase the storage life of hardy kiwifruit, we performed a cross between A. arguta (a local collection, ‘Hy2-1’, female) and A. deliciosa (‘Matua’, male) at Wando station at the Fruit Research Institute of JARES, Korea in 1999. After the first selection in 2006, we clonally propagated the hybrid plants by grafting them onto A. arguta seedlings in Gwangyang and Haenam province, Korea. We performed the final selection of this cultivar in 2012 and applied for plant protection rights from the Korea Forest Research Institute in 2013. Several experimental orchards have been established for commercial production. ‘Mansu’ begins to flower on May 20 in Gwangyang. The horticultural maturity date in ‘Mansu’, when the soluble solid content reaches 7°Bx, is October 15, whereas that of the control variety (‘Chiak’) is October 5. The average fruit size of ‘Mansu’ is approximately 15 g. The soluble solid content of ‘Mansu’ is approximately 16 to 17°Bx after ripening. The total yield of mature ‘Mansu’ vines is estimated to be 2.2 to 2.5 tons per 10a. The fruit firmness of ‘Mansu’ exceeded 1.5 kg/5 mmØ until 70 days after storage (at 0 and 1°C). Therefore, ‘Mansu’ fruits have much longer storability than the control. The cultivation and production of ‘Mansu’ may extend the marketing period for hardy kiwifruit.

Characterization of physiochemical and microbiological properties, and bioactive compounds, of flour made from the skin and bagasse of kiwi fruit (Actinidia deliciosa)

The objective of this study was to analyze the physicochemical and microbiological properties, as well as the bioactive compounds, of flour made from the skin and bagasse of two varieties (Bruno and Monty) of kiwi fruit (Actinidia deliciosa) at two stages of maturation. The flour made with kiwi fruit peel from both varieties showed higher levels of bioactive compounds and antioxidant activity that the flour made with bagasse from both varieties. The flour made with green kiwi fruit skin from the Bruno variety had higher DPPH values and levels of phenolic compounds (1262.34mg GAE/100g flour), while the Monty variety showed higher FRAP values, vitamin C (189.06mg/100g flour), flavonoids (486.47mg/100g flour), chlorophylls (12.13mg/100g flour) and carotenoids (246.91μg/100g flour). Flour made from kiwi fruit bagasse can be used to reduce agro-industrial waste. This flour is a promising ingredient which can be used to enrich products providing dietary fiber and bioactive compounds, as well as antioxidant action.

Kiwifruit allergy across Europe

Abstract Kiwifruit has a high nutritive and health value. Commercial plantings of kiwifruit started a few decades ago and in the last 30 years, it has become a widely consumed fruit. Nowadays, it is one of the most common causes of food allergy. Symptoms vary between mild symptoms in the oral cavity to severe anaphylactic reactions. To date, 13 kiwifruit allergens have been identified and are termed as Act d 1 through Act d 13. The use of kiwifruit components improves the diagnostic performance compared to skin prick-test and immunoCAP with kiwifruit extract. Kiwifruit allergen sensitization patterns differ across Europe with patients from Iceland, mainly sensitized to Act d 1 (actinidin), those from western/central and eastern Europe mainly sensitized to the birch pollen-related Act d 8, and patients from southern Europe mainly sensitized to Act d 9 (profilin) and Act d 10 (nsLTP). Act d 1 and having kiwifruit allergy in Iceland are independent risk factors for a severe kiwifruit allergy. Some kiwifruit cultivars (the common gold kiwifruit Hort16A and the more recently introduced green kiwifruit Summer 3373) may be less allergenic than the common green kiwifruit Hayward and may be a safe alternative for (part of) kiwifruit allergic patients.

REACTIONS OF KOREAN NEW CULTIVAR 'HAEGEUM' AGAINST MAJOR DISEASES OF KIWIFRUIT

‘Hayward’ (Actinidia deliciosa [A. Chev] Liang et Ferguson), which has been cultivated since the late 1970s, is the most popular green kiwifruit cultivar in Korea. However, ‘Hayward’ has been known to be susceptible to problematic foliar diseases such as bacterial canker, bacterial leaf spot, powdery mildew and fungal leaf spot diseases on kiwifruit trees grown at open-field orchards during growing season and postharvest fruit rot diseases during storage and distribution of harvested fruits. ‘Haegeum’ (A. chinensis Planchon), which is one of the new yellow kiwifruit cultivars bred in recent years, has been released at growers’ orchards since 2007 in Korea. Responses of ‘Haegeum’ against the major diseases of kiwifruit were compared with those of ‘Hayward’. The disease severities of the foliar diseases of ‘Hayward’ and ‘Haegeum’ were investigated at six naturally infected orchards during the growing season in 2013. The incidence rates of the postharvest fruit rot diseases on the fruits harvested in 2012 were also investigated at two naturally infected orchards. The disease severities of bacterial canker and bacterial leaf spot diseases were 18.5 and 63.5% on ‘Hayward’ at an orchard, but the disease severity of bacterial canker was 1.2% and no bacterial leaf spot was observed on ‘Haegeum’, respectively. Furthermore the disease severities of powdery mildew ranged from 9.4 to 84.8% on ‘Hayward’ at four orchards, while those on ‘Haegeum’ were less than 20%. The disease severities of leaf spot diseases induced by several fungi were 27.4 and 5.0% on ‘Hayward’ and ‘Haegeum’, respectively. The incidence rates of postharvest fruit rot diseases were 18.5% on ‘Hayward’ and 3.3% on ‘Haegeum’. The overall results reveal that ‘Haegeum’ is relatively resistant to the major diseases of kiwifruit compared with ‘Hayward’.

국내에서 소비되는 상용 식품의 비타민 K1함량 분석

Vitamin K1 (phylloquinone) content of commonly consumed foods in Korea were determined by solvent extraction followed by reversed-phase liquid chromatography using post-column derivatization and fluorescence detection. Samples were obtained in the years of 2013 and 2015. In this study, 46 vegetables, 14 fruits, and 6 legumes were analyzed. Relatively higher amounts of vitamin K1 were found in sweet potato leaves, green kiwi, and mung beans among vegetables, fruits, and legumes, respectively. The content of vitamin K1 in vegetables including spinach, broccoli, and potato ranged from non-detectable (ND) to 1,467.3 μg/100 g. The content of vitamin K1 in fruits ranged from ND to 42.7 μg/100 g. The content of vitamin K1 in legumes, including soybeans, mung beans and peas ranged from 1.7 to 63.4 μg/100 g. In addition, the analytical method validation parameters including recovery, reproducibility, repeatability, peak purity, and linearity were calculated to ensure the method's validity. The results showed high linearity with a correlation coefficient of 0.9999. Overall recovery was close to 100% (n=5). This study revealed reliable vitamin K content in commonly consumed foods in Korea for a nutritional information and food composition database.

수입산 열대·아열대 과일의 항산화 활성 비교연구

The objective of this study was to investigate the antioxidant activity of imported tropical and subtropical fruits including dragon fruits, green kiwi, papaya, pineapple, pomegranate, and yellow mango. A seventy percent of ethanol extracts were prepared. Total phenolic content, DPPH (1,1-diphenyl-2-picryl hydrazyl)-, ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), superoxide anion radical scavenging activity, FRAP (ferric reducing antioxidant power), tyrosinase inhibitory activity, and reducing power were investigated for the comparisons of antioxidant activities. The phenolic content expressed as gallic acid equivalents (GAE) was found to be highest in pomegranate (12.22 mg GAE/g), followed by pineapple (3.77 mg GAE/g). Pomegranate and pineapple exhibited higher antioxidant activity than those of other fruits except for FRAP. DPPH and ABTS radical scavenging activity from pomegranate were 93.00%, and 98.98%, respectively, at a concentration of 5 mg/mL, which were equal to those of ascorbic acid used for a positive control.

A Study on the Optimization of Green Kiwi and Gold Kiwi Puree Mixing Ratio for the Best French Kiwi Dressing

A Study on the Optimization of Green Kiwi and Gold Kiwi Puree Mixing Ratio for the Best French Kiwi Dressing

A Study on the Optimization of Green Kiwi and Gold Kiwi Puree Mixing Ratio for the Best French Kiwi Dressing

A Study on the Optimization of Green Kiwi and Gold Kiwi Puree Mixing Ratio for the Best French Kiwi Dressing

Elusive Structural, Functional, and Immunological Features of Act d 5, the Green Kiwifruit Kiwellin.

Kiwellin (Act d 5) is an allergenic protein contained in kiwifruit pulp in high amounts. The aim of this study was to investigate the three-dimensional structure of the natural molecule from green kiwifruit and its possible function. Kiwellin was crystallized, and its structure, including post-translational modifications, was elucidated. The molecular weight and structural features, in solution, were analyzed by gel filtration and circular dichroism, respectively. Although structurally similar to expansin, kiwellin lacks expansin activity and carbohydrate binding. A specific algorithm was applied to investigate any possible IgE reactivity correlation between kiwellin and a panel of 102 allergens, including expansins and other carbohydrate-binding allergens. The available data suggest a strong dependence of the kiwellin structure on the environmental/experimental conditions. This dependence therefore poses challenges in detecting the correlations between structural, functional, and immunological features of this protein.

Kiwifruit fermentation drives positive gut microbial and metabolic changes irrespective of initial microbiota composition

It is well established that individuals vary greatly in the composition of their core microbiota. Despite differing ecology, we show here that metabolic capacity converges under the pressure of kiwifruit substrates in a model gut system. The impact of pre-digested green and gold kiwifruit on the human colonic microbiota and their metabolic products was assessed using in vitro, pH-controlled, anaerobic batch culture fermenters. Phylogenetic analyses revealed that bacterial composition changed over time, irrespective of whether a substrate was added or not, indicating a natural adjustment period to the gut model environment. Adding kiwifruit substrate caused additional changes in terms of growth of specific bacterial groups, bacterial diversity and metabolite profiles. Relative abundance of Bacteroides spp. increased with both green and gold kiwifruit substrate while Bifidobacterium spp. increased only with green kiwifruit. NMR spectroscopy and GC demonstrated an increase in organic acids (primarily acetate, butyrate, and propionate) and a concomitant decrease in several amino acids and oligosaccharides following addition of green and gold kiwifruit substrate. The experiments demonstrated that despite markedly different baseline profiles in individual donor inoculum, kiwifruit components can induce substantive change in microbial ecology and metabolism which could have consequences for human health.

국내산 키위의 색상별 항산화능 및 아질산염 소거능 비교

This study was to conducted to investigate the antioxidative activity of 70% ethanol extracts of kiwi of three different colors (gold, green and red) by measuring DPPH, ABTS radical scavenging activity, tyrosinase inhibitory effect, metal chelating effect, reducing power, and nitrite scavenging activity. Total polyphenol contents were: gold kiwi, 3.09 mg GAE/g, green kiwi 2.71 mg GAE/g, and red kiwi 4.59 mg GAE/g, respectively. Red kiwi showed higher antioxdidant activity than gold and green kiwi. DPPH and ABTS radical scavenging activity, and nitrite scavenging activity of red kiwi exhibited 94.83, 99.57, and 97.88%, respectively, at a concentration of 20 mg/mL, which were equal to those of ascorbic acid (positive control). Metal chelating effect of red kiwi was superior to that of ascorbic acid. Therefore, the availability of red kiwi will be increased in the field of functional material for food additives and value added products.

Improvement of functional constipation with kiwifruit intake in a Mediterranean patient population: An open, non-randomized pilot study

Introduction: Kiwifruit consumption has shown to improve functional constipation in healthy elderly population, according to studies in New Zealand and China. The aim of this study was to evaluate the effect of kiwifruit intake on functional constipation in a Mediterranean patient population characterized by its distinctive nutritional habits.Material and Methods: An open, non-controlled and non-randomized longitudinal study was conducted in 46 patients with constipation (Rome III criteria). Patients monitored for five weeks: weeks 1 and 2 no kiwifruit and weeks 3-5 three kiwifruit per day (Green kiwifruit, Actinidia deliciosa var Hayward). Bristol Scale, volume of stools, and ease of defecation was self- reported daily. The evolution of the categorical variables was tested using the Bhapkar test; functional data methodology was used for continuous variables, and Generalized Estimating Equation (GEE) models were adjusted.Results: The percentage of patients with ≥3 stools per week increased from 82.61% (95% CI: 69–91.2) at week 1 to 97.78% (95% CI: 87.4–99.9) at week 2 of kiwifruit intake, with 76.09% (95% CI: 61.9–86.2) responding during the first week. The reporting of stable ideal stools increased from 17.39% (95% CI: 8.8–31) at week 2 to 33.33% (95% CI: 21.3–48) at week 5. According to GEE models, the number of depositions increased significantly (p-values<0.001) in 0.398 daily units at week 1 the first week of intake, up to 0.593 daily units at week 5; significant improvements on facility in evacuation and volume of evacuation were found from the firstweek of intake (all p-values<0.001).Conclusions: The intake of three kiwifruits per day significantly improves the quality of evacuation (number of depositions, volume, consistency and ease) in a Mediterranean patient population suffering from functional constipation.

Effect of Kiwifruit on Bone Resorption in Ovariectomized Mice

Kiwifruit is a good source of dietary components and has beneficial effects for health. In this study, we investigated the effects of two types of kiwifruit, green kiwifruit (GRK) and gold kiwifruit (GOK), on bone metabolism in ovariectomized (OVX) mice. Seven-week-old female Balb/c-strain mice were divided into four groups: sham-operated (sham) group, OVX group, and OVX mice that were fed a GRK-supplemented diet or GOK-supplemented diet. Freeze-dried GRK and GOK were prepared and added in the diet at a concentration of 3 g/100 g. After 9 wk, the mice were sacrificed, and the serum, uterus, and femurs were obtained. Final body weight did not differ significantly among the four groups. Compared to the sham group, uterine weight was significantly lower and serum C-terminal telopeptide of type I collagen (CTx) levels and receptor activator of NF-κB ligand (RANKL) mRNA expression of the whole femur were significantly higher in the OVX group. Compared to the OVX group, GRK, but not GOK, reduced serum CTx concentrations and RANKL mRNA expression of the whole femur without changes in uterine weight. These results suggest that the GRK inhibited bone resorption, which might be due to a decrease in RANKL mRNA expression in OVX mice.

Effects of Soy Phytoestrogens and New Zealand Functional Foods on Bone Health.

New Zealand is a rich source of food components that may have bioactivity on bone. Docosahexaenoic acid (DHA) from fish oil has been shown to maintain bone in ovariectomised (OVX) rats. Kiwifruit, a source of fibre and carotenoids, may also affect bone via a prebiotic as well as direct cell-based mechanisms. We aimed to 1) ascertain the effects of DHA on two cell models, including interactions with soy isoflavones; 2) and investigate the specific effects of carotenoids from kiwifruit as well as whole kiwifruit in cell-based and rodent models as well as in a human study. RAW 264.7 mouse monocytes or mouse bone marrow was used to generate osteoclasts (OC). Cells were exposed to the agents between 5 and 21 d and formation and activity of OC measured, including molecular markers. DHA inhibited OC formation in both cell models, including expression of cathepsin K, NFATc1 as well as actin ring formation. Combination with isoflavones enhanced these effects. In OVX rats and mice fed with kiwifruit for 8 wk, green kiwifruit reduced the rate of bone loss after OVX, and in mice it reduced C-telopeptide of Type 1 collagen (CTX) levels and RANKL expression while in menopausal women, green kiwifruit affected blood lipids and bone markers positively.

Encapsulated green kiwifruit extract: a randomised controlled trial investigating alleviation of constipation in otherwise healthy adults.

Previous clinical trials have shown bowel function is improved through consumption of whole kiwifruit (Actinidia deliciosa). This study investigated whether encapsulated kiwifruit extract (1 g/day) could alleviate constipation in otherwise healthy adults. Forty adults with confirmed constipation entered this trial, of which 32 completed with >80% compliance. Two capsules were self-administered morning and evening for 2 periods, each of 3 weeks duration, separated by a 3+ week washout in a double blind, randomised, placebo controlled crossover. Inclusion criteria included constipation with <=3 bowel movements (BM) per week. Daily records of defecation frequency and stool characteristics were obtained throughout treatment, as well as a measurement of gastrointestinal symptoms rating scale (GSRS) and quality of life (QoL) before and after each intervention arm. There was no difference in total BM over 3 weeks (p>0.05) or mean BM during each of weeks 1, 2 and 3 (p>0.05) between the kiwifruit extract and placebo when assessed from a faecal diary. There was also no detectable difference in defecation related scores of BM ease of defecation, volume, consistency or BM type assessed using Bristol stool chart scores. Nor was there a significant change in GSRS or QoL between pre and post treatment measures, when compared to placebo (p>0.05). This trial showed that improvement in bowel function or comfort was not achieved through supplementation with 1 g/day freeze dried kiwifruit extract. Efficacy from prior kiwifruit powder and whole fruit trials indicate that investigating higher doses of encapsulated kiwifruit extract may be worthwhile.

Yeast surface display is a novel tool for the rapid immunological characterization of plant-derived food allergens

High-throughput characterization of allergens relies often on phage display technique which is subject to the limitations of a prokaryotic expression system. Substituting the phage display platform with a yeast surface display could lead to fast immunological characterization of allergens with complex structures. Our objective was to evaluate the potential of yeast surface display for characterization of plant-derived food allergens. The coding sequence of mature actinidin (Act d 1) was cloned into pCTCON2 surface display vector. Flow cytometry was used to confirm localization of recombinant Act d 1 on the surface of yeast cells using rabbit polyclonal antisera IgG and IgE from sera of kiwifruit-allergic individuals. Immunological (dot blot, immunoblot ELISA and ELISA inhibition), biochemical (enzymatic activity in gel) and biological (basophil activation) characterization of Act d 1 after solubilization from the yeast cell confirmed that recombinant Act d 1 produced on the surface of yeast cell is similar to its natural counterpart isolated from green kiwifruit. Yeast surface display is a potent technique that enables fast immunochemical characterization of allergens in situ without the need for protein purification and offers an alternative that could lead to improvement of standard immunodiagnostic and immunotherapeutic approaches.

Spray-Drying of Green or Gold Kiwifruit Juice–Milk Mixtures; Novel Formulations and Processes to Retain Natural Fruit Colour and Antioxidants

This study describes novel formulations and approaches to produce reconstitutable (in water) spray dried kiwifruit milk powders that possess the intrinsic fruit colour and antioxidants of kiwifruits. Novel feed formulations, containing the aqueous fraction of green or gold kiwifruit puree, skim milk, fortifying zinc (in the form of zinc citrate) and a minimal amount of maltodextrin (3 % w/w), were spray dried at a relatively low inlet temperature (150 °C) to produce kiwifruit juice–milk powders with good dissolution efficiency (complete dissolution in 21–28 s), low water activity (0.22–0.28) and high retention of vitamin C, phenolics and carotenoid antioxidants. Both the green and gold kiwifruit juice–milk powders were pseudoplastic-like materials. Their reconstituted aqueous solutions had viscosity of 2–23 mPa · s and exhibited a shear rate dependence. Adding kiwifruit pulp residue to the feed solution at a mass ratio of 25:75 significantly enhanced the dissolution efficiency and the natural kiwifruit colour of the product powders without affecting the total phenolic and vitamin C contents. Preheating the feed solution to 50 °C for 1 min had a positive impact on the physicochemical attributes and bioactive profile of kiwifruit juice–milk powders, including a greater retention of initial kiwifruit juice colour, lower water activity, better dissolution efficiency and a higher total phenolic content. The powders obtained in this study contain multiple health-promoting nutrients and bioactives including kiwifruit antioxidants and milk proteins, and can be used in beverages or as functional ingredients for nutraceutical applications.

New insights on the bacterial canker of kiwifruit (Pseudomonas syringae pv. actinidiae)

Since 2008, Pseudomonas syringae pv. actinidiae , the causal agent of bacterial canker of kiwifruit has become the main pathogen of yellow and green fleshed kiwifruit. All major kiwifruit producing countries in the world have been affected by this ba

Influence of green and gold kiwifruit on indices of large bowel function in healthy rats.

The effects of kiwifruit on large bowel health were investigated in healthy rats. Four-week old Sprague-Dawley rats were given diets containing 10% homogenized green kiwifruit, gold kiwifruit or 10% glucose solution (control) over 4 or 6 wk. Green kiwifruit increased the fecal output compared to control. Growth of certain bacterial species in cecum was influenced by both green and gold kiwifruit. A significant increase in cecal Lachnospiraceae in rats fed the green kiwifruit diet was observed at week 4. At week 6, green and gold kiwifruit diets assisted in improving colonic barrier function by upregulating the expression of mucin (MUC)-2, MUC3, Toll-like receptor (TLR)-4 or trefoil factor-3 genes. Gold kiwifruit consumption increased the colonic goblet cells per crypt at week 6. Significant negative correlations between E. coli and β-defensin 1 and TLR4 expression were observed. Consuming green and gold kiwifruit for 6 wk significantly altered the biomarkers of large bowel health; indicating that regularly consuming kiwifruit helps attain optimal digestive health.