•Flours of kiwi fruit can be considered as sources of dietary fiber and bioactive compounds.•The flours of kiwi fruit skin had a higher antioxidant activity than the flour of the bagasse.•By-products ...of kiwi fruit can contribute to the reduction of agro-industrial waste.Please check the edits made in the highlights and correct if necessary.
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.
•Factors influencing diverse chemical properties in kiwifruits are highlighted.•Various bioactive compounds and biological activities of kiwifruits are reviewed.•Functionalities and properties of ...kiwifruit ingredients are comparatively analyzed.•Valorization of underutilized kiwifruit resources has great potential.•Diverse kiwifruit-derived products for food and other industries are summarized.
Kiwifruit (Actinidia spp.) is a commercially important fruit crop. Various species and cultivars, non-fruit plant parts, and agricultural and processing wastes are underutilized. A broad-scoped review of kiwifruit guides further innovative applications. Different kiwifruit varieties and edible and nonedible parts varied in the composition of dietary nutrients including polyphenols, vitamins, dietary fiber, and functional ingredients, such as starch and protease and bioactive phytochemicals. Kiwifruits exhibit antioxidative, antiproliferative, antiinflammatory, antimicrobial, antihypertensive, antihypercholesterolemic, neuroprotective, antiobese properties and promote gut health. Clinically significant effects of kiwifruit on prevention and/or treatment of major chronic diseases are not yet evident. Varieties and plant parts, extraction, analytical and processing methods affect the physicochemical and biological properties of kiwifruit-derived ingredients. Allergens, mycotoxins, pesticides and heavy metals are the chemical hazards of kiwifruits. Future research should be focused on sustainable uses of underutilized resources as functional ingredients, bioactive compound purification, composition-activity relationships, and physiological mechanisms and clinical significance of kiwifruits.
Green synthesis of fluorescent nitrogen doped carbon dots (N-CDs) using Actinidia deliciosa (A. deliciosa) fruit extract as a carbon precursor and aqueous ammonia as a nitrogen dopant is reported ...here. The synthesized N-CDs were characterized by high resolution transmission electron microscopy (HR-TEM), energy dispersive spectroscopy (EDS), selected area electron diffraction (SAED), UV–Visible spectroscopy (UV–Vis), fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The average size of the N-CDs was approximately 3.59 nm and the calculated inter layer distance was found to be 0.21 nm. Raman spectroscopy and SAED pattern revealed the graphitic nature of the synthesized N-CDs. The N-CDs were found to emit intense blue color at 405 nm under the excitation of 315 nm. The doping of nitrogen over the surface of the N-CDs was confirmed by EDS, FT-IR and XPS studies. The synthesized N-CDs were found to exhibit excellent catalytic activity in the reduction of Rhodamine-B using sodium borohydrate. The MTT assay was used to evaluate the cytotoxicity and biocompatibility of N-CDs towards L-929 and MCF-7 cells. From the results obtained, it was found that the N-CDs exhibit low cytotoxicity and superior biocompatibility on both L-929 and MCF-7 cells.
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•Facile synthesis of fluorescent N-CDs from A. deliciosa extract is reported.•The average size of the synthesized N-CDs was 3.59 nm and graphitic in nature.•The synthesized N-CDs accelerated Rhodamine-B reduction by NaBH4.•The fluorescent N-CDs were found good biocompatibility and low cytotoxicity.
The root of Actinidia deliciosa has been used as traditional drugs in China for a long time. This study therefore aimed at investigating the hepatoprotective bio-active components from the root of A. ...deliciosa comprehensively and accurately, thus promoting the exploitation and utilization of the whole resource of A. deliciosa. For the purpose of this study, the roots of A. deliciosa were fractionated into various extract fractions with differential polarity solvent. The hepatoprotective activities of various solvent extracts were assessed by examining the effect on carbon tetrachloride (CCI sub(4))-induced hepatotoxicity in rats. The highest hepatoprotective activities fraction was further isolated with column chromatography. The structures of the activities monomers were identified with modern spectrum technology such as infrared (IR), ultraviolet (UV), electron impact mass spectrometry (EI-MS), proton nuclear magnetic resonance ( super(1)H-NMR), carbon nuclear magnetic resonance ( super(13)C-NMR) and distortionless enhancement by polarization transfer-nuclear magnetic resonance (DEPT-NMR). Of the various extract fractions, the ethyl acetate extract (Fr3) exhibited the highest hepatoprotective activities (p<0.05). When the Fr3 was separated into five fractions by silica gel chromatography, among the five fractions fraction, Fr9 showed the highest yield and the highest hepatoprotective activities. When using Fr9 at a dose of 200 mg/kg to pre- and post-treat the CCI sub(4)-induced rat, the activities of alanine transaminase (ALT) decreased by 90.10 and 88.60%, aspartate transaminase (AST) decreased by 80.69 and 79.92% in rat serum, the lipid peroxidation (malondialdehyde (MDA)) decreased by 42.11 and 45.53%, while glutathione (GSH) increased by 114.12 and 147.62% in the rats liver homogenate, respectively as compared with that of the CCI sub(4) control rats. The fraction Fr9 was further separated into five fractions using silica gel chromatography, which were investigated for the main chemical constituents by column chromatography techniques, physico-chemical constants and spectroscopic analysis. Its main chemical constituents were three triterpenoids named 3 beta -hydroxy-urs-12-en-28-oic acid (ursolic acid), 2 alpha ,3 alpha ,23-trihydroxy-urs-12-en-28-oic acid and 2 alpha ,3 beta ,19,23-tetrahydroxy-urs-12-en-28-oic acid. The findings indicate that the high hepatoprotective activity of the fraction of A. deliciosa root is due to its enriched triterpenoid.
•There are few control options for Psa infection of Actinidia deliciosa.•We used endophytic bacteria from Leptospermum scoparium (mānuka) to control Psa.•Endophytic bacteria were transmissible to ...Actinidia deliciosa by wound inoculation.•The endophytic bacteria inhibited colonization by Psa and reduced disease severity.
Pseudomonas syringae pv. actinidiae (Psa) is the causal agent of bacterial canker in kiwifruit (Actinidia deliciosa). Mānuka (Leptospermum scoparium) is a New Zealand medicinal shrub that produces essential oils with antimicrobial properties. The aim of this study was to determine whether endophytes from L. scoparium could be transferred to A. deliciosa and maintain their biocontrol activity. Five endophytic bacteria showed antagonism against Psa in vitro. The endophytic bacteria possessed multiple antibiotic producing genes, such as phenazine, 2,4-DAPG, and hydrogen cyanide, compounds that are known to inhibit growth of bacterial plant pathogens. Spontaneous chloramphenicol mutants and BOX-PCR fingerprinting were used to monitor endophytic colonization of antagonistic bacteria in planta. Three endophytic bacteria were transmissible to A. deliciosa by wound inoculation where they inhibited colonization by Psa and reduced disease severity in two different commercial cultivars.
ALFIN-like transcription factors (ALs) are involved in several physiological processes such as seed germination, root development and abiotic stress responses in plants. In carrot (Daucus carota), ...the expression of DcPSY2, a gene encoding phytoene synthase required for carotenoid biosynthesis, is induced after salt and abscisic acid (ABA) treatment. Interestingly, the DcPSY2 promoter contains multiple ALFIN response elements. By in silico analysis, we identified two putative genes with the molecular characteristics of ALs, DcAL4 and DcAL7, in the carrot transcriptome. These genes encode nuclear proteins that transactivate reporter genes and bind to the carrot DcPSY2 promoter in yeast. The expression of both genes is induced in carrot under salt stress, especially DcAL4 which also responds to ABA treatment. Transgenic homozygous T3 Arabidopsis thaliana lines that stably express DcAL4 and DcAL7 show a higher survival rate with respect to control plants after chronic salt stress. Of note is that DcAL4 lines present a better performance in salt treatments, correlating with the expression level of DcAL4, AtPSY and AtDXR and an increase in carotenoid and chlorophyll contents. Likewise, DcAL4 transgenic kiwi (Actinidia deliciosa) lines show increased carotenoid and chlorophyll content and higher survival rate compared to control plants after chronic salt treatment. Therefore, DcAL4 and DcAL7 encode functional transcription factors, while ectopic expression of DcAL4 provides increased tolerance to salinity in Arabidopsis and Kiwi plants.
The effect of nanoemulsion coatings with antioxidant and antimicrobial agents on the physicochemical, antioxidant properties and microbial stability of ready to eat fresh cut kiwi slices during ...storage at 5 ± 1 °C for 7 days was studied. Nanoemulsion coating formulations used were alginate 2% (w/w) and carboxymethylcellulose 2% (w/w) containing Tween 80 (2 mg), ascorbic acid 0.5% and vanillin 0.5 and 1.0%. Fresh cut kiwi slices were coated with nanoemulsion coatings, while the uncoated sample dipped in water served as control. Average drop diameter of the nanoemulsions was between 220 and 335 nm. Nanoemulsions had high negative ζ-potential value, significantly (P ≤ 0.05) lower viscosity and whiteness index values than coarse emulsions. During storage fresh cut kiwi fruit quality attributes especially weight loss, titratable acidity, total soluble solids, pH, ascorbic acid, firmness and microbial load were measured. Results confirmed that nanoemulsion coatings significantly delayed physiological weight loss 8–14%, decay percentage 3–59%, retained firmness 14.1–17.9 N, DPPH radical scavenging activity 53–59% and ascorbic acid content 73–79 mg 100−1 g compared to control. Dispersion of several concentrations of the antimicrobial agent in a combination with emulsion coatings successfully slowed bacteria, yeast and mold growth during storage, thus leading to increased shelf life of fresh cut ready to eat kiwi fruit during storage.
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•Nanoemulsion treatments enhanced the shelf life of fresh cut kiwi fruits.•Coatings significantly minimized weight loss and decay percentages.•Firmness and other quality parameters were retained using nanoemulsion coatings.•Nanoemulsion coatings successfully reduced bacteria, yeast and mold counts.
•The softening pattern on-vine and in storage is sigmoidal.•The portion of the sigmoidal seen in storage depends on the softening rate at harvest.•Fruit develop a capacity to soften in response to ...low temperature whilst on the vine.•This capacity develops 1–2 weeks before the start of faster softening on the vine.•Temperatures in the region of 8–10°C can increase the softening rate.
Observations were made on the softening of ‘Hayward’ kiwifruit on the vine, in storage and in response to low temperatures. The pattern of ‘Hayward’ softening on the vine and in storage was sigmoidal, as is typical for kiwifruit. On the vine, the initial slow softening rate of ‘Hayward’ fruit was consistent across seasons, and similar to other cultivars, at ∼2.9N/week or less. The rate of rapid softening differed among cultivars at 5.9–14.7N/week. In storage, the initial slow phase of softening was seen only in less mature fruit harvested before any increase in softening rate had occurred on the vine. Maturing ‘Hayward’ fruit developed a capacity to soften in response to low temperatures 1–2 weeks before the on-vine period of faster softening commenced. There appear to be three aspects of fruit softening to consider in response to temperature: induction of softening at low (e.g. 8–10°C) but not chilling temperatures, slowing of the biochemical reaction rates that cause softening by lower temperatures (e.g. 4°C) and chilling by low temperatures close to 0°C. These findings are discussed in the context of implementing research and the potential commercial impacts from a better understanding of temperature effects on kiwifruit softening.
•Increased rate of soluble solids (SS) accumulation can start before nett starch loss.•The period between the end of starch accumulation and nett starch loss is variable.•Developmentally programmed ...nett starch loss may be pre-empted by low temperature.•‘Hayward’ is late maturing – low temperature & increased SS accumulation may coincide.•Chilling tolerance for storage is associated with dark seeds and cessation of growth.
A harvest index of 6.2% soluble solids content (SSC) has long been used for New Zealand-grown ‘Hayward’ kiwifruit destined for storage and export, based on the soluble solids accumulation rate at this point having increased because of starch breakdown in response to low night temperatures. Fruit maturation in ‘Hayward’ and other kiwifruit cultivars has been investigated through monitoring changes in SSC, soluble carbohydrates and starch content as fruit developed on the vine. The initial increase in the rate of soluble solids accumulation was not necessarily the result of starch breakdown, occurring before a nett decrease in starch and possibly the direct result of imported soluble carbohydrates. It is suggested that SSC should be considered in the context of starch metabolism, for which there is a progression from starch accumulation to starch degradation, with a period of variable duration of no nett change in starch between these. The increased rate of soluble solids accumulation of fruit at 6.2% SSC may occur through either import of soluble carbohydrate or starch breakdown. Hence fruit at the same SSC may differ physiologically, thereby affecting fruit postharvest performance. The loss of temperature sensitivity of ‘Hayward’ kiwifruit occurred over a period of weeks and was initially associated with the change to dark seed coats, and was complete in association with the cessation of growth.
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•pHBA inhibited A. flavus growth by blocking cytokinesis.•pHBA inhibited aflatoxin biosynthesis by A. flavus.•Exogenous pHBA promoted endogenous pHBA accumulation in ...kiwifruit.•Exogenous pHBA induced oxidative stress in A. flavus-infected kiwifruit.•Application of pHBA reduced A. flavus advancement in kiwifruit.
Aspergillus flavus not only reduces kiwifruit production but also synthesizes carcinogenic aflatoxins, resulting in a relevant threat to human health. p-Hydroxybenzoic acid (pHBA) is one of the most abundant phenolics in kiwifruit. In this study, pHBA was found to reduce A. flavus mycelial growth by blocking the fungal mitotic exit network (MEN) and cytokinesis and to inhibit the biosynthesis of aflatoxins B1 and B2. The application of pHBA promoted the accumulation of endogenous pHBA and induced oxidative stress in A. flavus-infected kiwifruit, resulting in an increase in H2O2 content and catalase (CAT) and superoxide dismutase (SOD) activities. Preventive and curative treatments with 5 mM pHBA reduced A. flavus advancement by 46.1% and 68.0%, respectively. Collectively, the antifungal and elicitor properties of pHBA were examined for the first time, revealing new insights into the role of pHBA in the defense response of kiwifruit against A. flavus infection.
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