Red Kiwifruit Research Articles

Effects of different packaging method on oxidation stability and tenderness of chicken breast injected with different types of kiwifruit during storage

SummaryThis study aimed to investigate the antioxidant and protease activities of red kiwifruit (RK), green kiwifruit (GRK), and gold kiwifruit (GOK) and determine the effects of various packaging methods on the quality of chicken breast injected with various kiwifruit types during storage. The physicochemical and textural properties of chicken breasts containing various kiwifruit types were evaluated. Chicken breasts were injected with brine solution containing 5% kiwifruit powder, and their product quality was measured every 3 days until day 9. GOK and RK addition to chicken breast delayed oxidation during storage. Adding GOK and GRK to chicken breast was found to increase tenderness. Modified‐atmosphere packaging (MAP) delayed microbial growth more effectively than over‐wrap packaging (OWP). These findings suggest that the combination of GOK and MAP potentially extends shelf‐life without deteriorating quality.

Hydrolytic and antioxidant activities of pork loin protein hydrolysates treated with various freeze‐dried kiwifruit powders during incubation

SummaryThis study aimed to evaluate the protease activity of freeze‐dried kiwifruits as affected by the various colours and the antioxidant activities of protein hydrolysates from pork loin protein (sarcoplasmic and myofibrillar proteins) containing different freeze‐dried kiwifruit powder during incubation times. The protease activity of freeze‐dried kiwifruit powders was determined using casein and meat protein as substrates. Gold and green kiwifruit powders showed higher protease activity than red kiwifruit powders. Each type of kiwifruit showed different hydrolysis degrees for myofibrillar and sarcoplasmic proteins. The myofibrillar and sarcoplasmic proteins with kiwifruit powder showed increased antioxidant activity compared to the control. The protein hydrolysates obtained from pork loins treated with green and gold kiwifruit powders increased antioxidant activity with increased incubation time. These results suggested that the protein hydrolysates of pork loins containing freeze‐dried kiwifruit powders had potential antioxidant activity, resulting in maintaining meat product quality during storage.

Assessing Consumer Preferences for New Red-Pulp Kiwifruit: Application of a Choice Experiment between Different Countries.

The central objectives of this paper are to enhance the understanding of how consumers in developed economies value credence attributes and to understand their preferences for red-pulp kiwifruit. To achieve this, we utilised the choice experiment method through surveys conducted in Italy, Spain, France, and Germany, targeting kiwifruit consumers through specific questionnaires. Regarding red kiwifruit, a significant percentage of those who are already familiar with them either purchase or intend to purchase them. What is equally interesting is the high percentage of those who declared themselves to be undecided about making a purchase. Specific marketing actions can be directed towards the following two categories: converting the intention to purchase into an actual purchase and shifting the current inclination towards an intention or act of purchase, for example, by improving the knowledge about this relatively unknown fruit. This paper contributes to the market chain by assessing consumers' choice and willingness to pay for red kiwifruit, while also comparing developed economy markets.

Synthesis of γ-cyclodextrin metal-organic framework as ethylene absorber for improving postharvest quality of kiwi fruit

In this study, we developed an edible metal-organic framework (MOF) based on K+ and γ-cyclodextrin (γ-CD), named γ-CD-MOF-K, using ultrasonication. A structural analysis demonstrated that MOF had good adsorption performance for ethylene gas: 56% ± 0.67% (w/w). Molecular docking technology found that γ-CD-MOF-K had a spindle cavity structure, which can effectively adsorb and store ethylene gas. The results showed that the material could effectively absorb ethylene gas in storage packaging and delay red kiwi fruit ripening. Therefore, MOF exhibits great potential to improve the postharvest quality of fruits and vegetables.

Integrating untargeted metabolites and targeted analysis for discrimination of kiwifruits from different cultivars

To investigate the differences among kiwifruits from six different cultivars (Actinidia chinensis, Actinidia delicosa and Actinidia arguta), UPLC-QTOF-MS and UPLC-ESI-MS/MS coupled to multivariate statistical analysis were applied to untargeted metabolites and targeted analysis of kiwifruit samples for the first time. In untargeted analysis, the metabolome of kiwifruits was exhibited by principal component analysis (PCA), a total of 44 up-regulated feature compounds were screened based on the orthogonal partial least squares-discriminant analysis (OPLS-DA) and identified as glycosyl compounds, hydrocinnamic acids and various flavonoids. Furthermore, the contents of 27 targeted procyanidins, flavonoids and hydrocinnamic acids were analyzed by a UPLC-ESI-MS/MS method. It was indicated that phenol glycosides were much higher in A. arguta, responsible for the aroma of kiwifruits, various quercetin glycosides were higher in A. arguta, and much higher flavan-3-ols and hydrocinnamic acids were rich in A. Chinensis cv. Hongyang (red) kiwifruits. In addition, the results of chemometric analysis showed the untargeted metabolites and targeted compounds were responsible for the classification on the kiwifruits, which can benefit the scientific understanding of chemical diversity for kiwifruits, and improve the investigation of new wild kiwifruit cultivars, especially red kiwifruit and A. arguta.

Nutrient and phenolic composition of Zespri™ Red Kiwifruit

Nutrient and phenolic composition of Zespri™ Red Kiwifruit

저온 저장이 레드키위 과실 품질에 미치는 영향

This studies was conducted to investigate the effect of cold storage on red kiwi fruit quality by cultivar. As a result of investigating the firmness and acidity of fruit after cold storage, the firmness and acid content decreased in all cultivars, and sugar content increased in all cultivars. The reason for the decrease in acid content during cold storage of kiwi is that it is converted from organic acid to sugar and used for breathing. And the reason for the increase of The total soluble solids (TSS) during storage is that it is converted from starch to sugar. ‘Hongyang’ had a commodity rate of 94.4% and a non-commodity of 5.6% on February 5, 110 days after storage. ‘EnzaRed’ had a commodity rate of 93.9% and a non-commodity of 6.1% on January 15, 89 days after storage. ‘QiHong’ had a commodity rate of 94.8% and a non-commodity rate of 5.2% on February 23, 113 days after storage. The appropriate cold storage period for each culrivar is considered to be 110 days for ‘Hongyang’, 89 days for ‘EnzaRed’, and 113 days for ‘QiHong’.

Global Mid-Infrared Prediction Models Facilitate Simultaneous Analysis of Juice Composition from Berries of Actinidia, Ribes, Rubus and Vaccinium Species

Introduction of Fourier-transform infrared (FTIR) spectroscopy would enable breeders to screen phenotypic variability in multiple fruit from large numbers of progeny. Thus far, however, there has been no comprehensive attempt to develop chemometric models for determination of quality attributes of small berry species by this approach. FTIR spectra (1800–900 cm−1) of juice from breeding populations of four genera (Actinidia, specifically red kiwifruit, Ribes, Rubus and Vaccinium) were analysed by partial least squares regression to determine the possibility of measuring soluble solids (SS), titratable acidity (TA) and total anthocyanin (ACY) concentration simultaneously using global prediction models. SS, TA and ACY concentrations across all berry juices ranged between 4.1 and 22.4 °Brix, 0.1–5.5% citric acid and 2–4697 ppm, respectively. R2 (coefficient of determination in cross-validation) and SECV (standard error of cross-validation) statistics for global models were 0.996 (0.22 °Brix), 0.996 (0.08% citric acid) and 0.893 (280 ppm). Analysis of data sets for individual berry types separately demonstrated that it was possible to develop models with superior prediction statistics for each attribute. However, these were not necessarily robust when validated against data from different seasons, locations or breeding selections. These global models represent an advance for researchers wishing to screen substantial fruit populations more rapidly.

Environmental and management factors contributing to variability in flesh colour of a red kiwifruit cultivar in New Zealand

Abstract Consistency of flesh colouration is important for commercial acceptance of red-fleshed Actinidia chinensis cultivars, but colour variation between and within orchards is widely reported. Physiological and environmental factors reported to influence this variability include parent cane and shoot type, ploidy of pollen parent, and high temperatures, specifically cumulative time above 25 °C over the growing season. However, the impacts of temperature in a temperate climate (e.g. New Zealand) on colour variability have not been explored. Light, a commonly reported influence on anthocyanin expression in other plants, does not directly influence red kiwifruit colour but the indirect effects of light exposure are unknown. This study explored the colour variability found in eight New Zealand red kiwifruit orchards spread across five regions and examined correlations of environmental conditions (temperature and light exposure) with fruit colour. Two harvests were collected from each orchard in 2014, with two further harvests being conducted in one orchard in 2015. It was found that the variation between orchards and regions was larger than within orchards but no clear regional patterns existed. A significant relationship existed between softer fruit and stronger red colouration, measured by hue angle and outer pericarp colour score. A significant relationship also existed between increased flesh colour and higher number of leaf layers, lower estimated light exposure, and paler skin colour, with skin colour score having the largest effect on flesh colour. No significant correlations between temperature in March and colour expression were found, but three out of the four lower colour orchards had significantly more hours above 25 °C during March. Collectively, these data suggest that full colour development may be promoted directly by carbohydrate supply from a denser canopy and is probably negatively affected by excessive fruit temperatures that may be more common under poorly-developed canopies or in areas with high daily maximum temperatures.

Kiwifruit R2R3-MYB transcription factors and contribution of the novel AcMYB75 to red kiwifruit anthocyanin biosynthesis

Red kiwifruit (Actinidia chinensis) is a popular fresh fruit with a high market value due to its unique color, caused by anthocyanin accumulation. The R2R3-MYB transcription factors (TFs) have important roles in plant development and anthocyanin metabolism. In this first comprehensive study of R2R3-MYBs in kiwifruit, a total of 93 R2R3-MYB genes, including five novel previously unannotated AcMYBs, were identified. Their phylogenic relationship, exon-intron structures, and conserved motifs were analyzed. Based on transcriptome data, 60 AcMYBs were expressed (FPKM > 1) across seven developmental stages of kiwifruit, revealing five expression patterns. One of the 5 newly identified R2R3 TFs, AcMYB75, showed an anthocyanin accumulation-linked expression pattern during fruit development. AcMYB75 localized to the nucleus and has an active transactivation domain, verifying it as a transcription factor. AcMYB75 protein specifically bound the promoter of the anthocyanin biosynthesis gene ANS in yeast one-hybrid system and in vivo. In 35 S:AcMYB75 Arabidopsis plants, anthocyanin significantly accumulated in leaves, and the expression of anthocyanin biosynthetic genes was greatly up-regulated. Together, these results suggest that AcMYB75 is involved in anthocyanin biosynthesis in kiwifruit. These findings will increase our understanding of AcMYBs involved in anthocyanin biosynthesis, and also benefit further functional characterization of R2R3-MYB genes in kiwifruit.

Effects of high carbon dioxide and ethylene treatment on postharvest ripening regulation of red kiwifruit (Actinidia melanandra Franch) during cold storage

The effect of high carbon dioxide and ethylene treatment on postharvest ripening regulation of red kiwifruit (Actinidia melanandra) was investigated during cold storage. Physio-chemical properties such as weight loss, firmness, SSC, acidity, and market quality were analysed in red kiwifruit held at 10oC compared to the fruit treated with carbon dioxide and ethylene during 75 days of storage. No significant weight loss was detected in red kiwifruit treated with carbon dioxide until 75 days of storage while the most rapid loss was found in fruit treated with ethylene. In ethylene-treated fruit, the firmness was dramatically reduced from 4.2kg on the first day to 1.2 kg after 27 days of storage at 10℃. However, the firmness of the carbon dioxide-treated fruit was 1.8kg after 54 days of storage. The highest level of SSC(%) was investigated within the 27 storage days at 10℃ for fresh red kiwifruit treated with exogenous ethylene,whereas the carbon dioxide-treated fruit exhibited a greatly increasedSSC after 64 days. The carbon dioxide-treated red kiwifruit maintained statistically(p<.01) higher levels of acidity compared to the control and the exogenous ethylene-treated ones during 41 days of storage at 10℃. The SSC/Acid ratio of fruit treated with carbon dioxide was significantly lower (p<.01) maintained than the other two treatments (ethylene-treated and control fruit)throughout the 75-dayexperiment. Based on the quality characteristics of postharvest red kiwifruit, it could be concluded that the carbon dioxide treatment significantly delayed the ripening process and maintained the market quality of harvested red kiwifruit, which can be a potential application for commercial use in the kiwi industry

Chitosan coating of red kiwifruit (Actinidia melanandra) for extending of the shelf life

Commercial production of red kiwifruit (Actinidia melanandra) has been unsuccessful because of its short shelf life. Here in this study, we used chitosan to extend the shelf life of red kiwifruit berries. Chitosan (with 70–75% deacetylation degree and low molecular weight) was dissolved in acetic acid (at pH 2.0–2.3) to obtain gel material, which was used for coating of the fruit. The coated and uncoated samples were kept for 26 days at room temperature (20±2°C). The changes in the weight loss, firmness, soluble solid content, total polyphenol content and ascorbic acid content were evaluated. All these findings showed that chitosan could be an effective coating material for berries of red kiwifruit to extend its short shelf life.

Gene Expression Profiling of Development and Anthocyanin Accumulation in Kiwifruit (Actinidia chinensis) Based on Transcriptome Sequencing

Red-fleshed kiwifruit (Actinidia chinensis Planch. ‘Hongyang’) is a promising commercial cultivar due to its nutritious value and unique flesh color, derived from vitamin C and anthocyanins. In this study, we obtained transcriptome data of ‘Hongyang’ from seven developmental stages using Illumina sequencing. We mapped 39–54 million reads to the recently sequenced kiwifruit genome and other databases to define gene structure, to analyze alternative splicing, and to quantify gene transcript abundance at different developmental stages. The transcript profiles throughout red kiwifruit development were constructed and analyzed, with a focus on the biosynthesis and metabolism of compounds such as phytohormones, sugars, starch and L-ascorbic acid, which are indispensable for the development and formation of quality fruit. Candidate genes for these pathways were identified through MapMan and phylogenetic analysis. The transcript levels of genes involved in sucrose and starch metabolism were consistent with the change in soluble sugar and starch content throughout kiwifruit development. The metabolism of L-ascorbic acid was very active, primarily through the L-galactose pathway. The genes responsible for the accumulation of anthocyanin in red kiwifruit were identified, and their expression levels were investigated during kiwifruit development. This survey of gene expression during kiwifruit development paves the way for further investigation of the development of this uniquely colored and nutritious fruit and reveals which factors are needed for high quality fruit formation. This transcriptome data and its analysis will be useful for improving kiwifruit genome annotation, for basic fruit molecular biology research, and for kiwifruit breeding and improvement.

Low Temperature Increases Ethylene Sensitivity in Actinidia chinensis ‘Rainbow Red’ Kiwifruit

Premature softening during low-temperature storage is a major issue in the red kiwifruit (Actinidia chinensis Planch.) cultivar ‘Rainbow Red’. The objective of this study was to investigate the effect of low temperature on ethylene sensitivity in this cultivar. We demonstrate how ethylene preconditioning at 4°C and 25°C interacted with more rapidly ripening at the lower temperature in ‘Rainbow Red’ kiwifruit. The expression of ripening-related genes ACS1, ACO3, EIL4, ERF14, and PGB was at the basal level during ethylene preconditioning at 4°C and 25°C, and rapidly increased with ethylene treatment following ripening. These results suggest that low-temperature storage enhances ethylene sensitivity in ‘Rainbow Red’.

Characterization and Quantification of Anthocyanins in Red Kiwifruit (Actinidia spp.)

Red-fleshed fruit occur in a small number of distantly related taxa in different sections of the genus Actinidia (kiwifruit). We describe and identify the anthocyanin profile of fruit of several Actinidia species. Differences in the relative amounts of cyanidin- and delphinidin-based anthocyanins determine whether the fruit appear red or purple. Cyanidin derivatives have been found in all Actinidia species that contain anthocyanins, whereas delphinidin derivatives are limited to two taxa: A. melanandra and A. arguta var. purpurea . The fruit of these not only contain a wider range of anthocyanins, but they also have greater concentrations. Anthocyanins of most Actinidia species are usually conjugated with either xylosyl-galactose or galactose, whereas A. deliciosa anthocyanins are conjugated with glucose and galactose.

Isolation and Structural Identification of the Anthocyanin Components of Red Kiwifruit

The anthocyanins responsible for the red color of red kiwifruit were extracted in acidified ethanol and isolated by solid phase extraction (SPE) followed by preparative HPLC. Five anthocyanins were obtained and subsequently identified as delphinidin 3-[2-(xylosyl)galactoside], delphinidin 3-galactoside, cyanidin 3-[2-(xylosyl)galactoside], cyanidin 3-galactoside, and cyanidin 3-glucoside by a combination of LC-MS/MS, GC-MS, and 2D NMR. Delphinidin 3-[2-(xylosyl)galactoside] and delphinidin 3-galactoside have not previously been reported in the genus Actinidia.