Green Kiwifruit Research Articles

Evaluation of green kiwifruit juice extract on physicochemical properties, antioxidant activity, and tenderness of beef M. semitendinosus with in vitro digestion.

This study focused on the physicochemical properties and tenderness of vacuum-packaged beef M. semitendinosus as affected by various dilution ratios (DRs, 1:4, 1:2, and 1:1) of green kiwifruit juice extract (GKJE) with phosphate buffer during storage at 4°C for 7 days. In addition, the formation of peptides with antioxidant activity for GKJE ability to hydrolyze proteins present in beef was evaluated at different steps of in vitro digestion. Beef with GKJE showed higher tenderness than control (CTL, beef with brine solution alone) during storage, and the increased DR increased tenderness as compared to lower DRs. The addition of GKJE increased protein digestibility during in vitro digestion. To increase the antioxidant activity in the body, GKJE having a DR of 1:2 and 1:1 should be applied to the beef muscle with effective antioxidant activity. These results suggest that DRs of phosphate buffer and kiwifruit juice of 1:1 and 1:2 have the potential to be used as a meat-tenderizing agent and could increase the digestibility of meat as well as the antioxidant capability of bioactive peptides. PRACTICAL APPLICATION: The dilution ratio of kiwi juice with phosphate buffer at 1:1 has the potential to be used as a meat-tenderizing agent during refrigerated storage and also increase the digestibility of beef.

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.

Actazin® green kiwifruit powder consumption at 600 mg per day for 28 days improves stool form and relieves occasional constipation in healthy individuals: A randomized controlled trial

Constipation is a global issue which impacts quality of life. Kiwifruit promote laxation without the urgency induced by therapeutic laxatives. Actazin® is a skinless, seedless, cold-processed green kiwifruit powder previously shown to improve laxation at 2400 mg daily dosages. Here we investigated the laxation support provided by a 600 mg daily dosage of Actazin.A randomized, double-blinded, placebo-controlled parallel study for 28 days across four North American sites (NCT03462199) enrolled 85 participants with non-pathological constipation who had ≤3 complete spontaneous bowel movements (CSBM) per week. Participants consuming Actazin reported improved Bristol stool form scores (BSFS) over placebo (p < 0.05), improving the normality of stool form. Both Actazin and placebo showed improvements of >1 CSBM per week over baseline (p < 0.05). Actazin was safe and well tolerated by participants and resulted in changes (p < 0.05) in the relative abundance of fecal bacterial taxa consistent with consumption of kiwifruit cell wall components.This study demonstrated that once daily supplementation of 600 mg Actazin green kiwifruit powder resulted in clinically significant improvements in stool form and improved participant bowel habits in healthy individuals with occasional constipation. To the best of our knowledge this is the first recorded observation of this BSFS improvement over placebo by a kiwifruit product.

In-vitro and in-silico analyses of the thrombolytic potential of green kiwifruit

Cardiovascular diseases (CVDs), mainly caused by thrombosis complications, are the leading cause of mortality worldwide, making the development of alternative treatments highly desirable. In this study, the thrombolytic potential of green kiwifruit (Actinidia deliciosa cultivar Hayward) was assessed using in-vitro and in-silico approaches. The crude green kiwifruit extract demonstrated the ability to reduce blood clots significantly by 73.0 ± 1.12% (P < 0.01) within 6 h, with rapid degradation of Aα and Bβ fibrin chains followed by the γ chain in fibrinolytic assays. Molecular docking revealed six favorable conformations for the kiwifruit enzyme actinidin (ADHact) and fibrin chains, supported by spontaneous binding energies and distances. Moreover, molecular dynamics simulation confirmed the binding stability of the complexes of these conformations, as indicated by the stable binding affinity, high number of hydrogen bonds, and consistent distances between the catalytic residue Cys25 of ADHact and the peptide bond. The better overall binding affinity of ADHact to fibrin chains Aα and Bβ may contribute to their faster degradation, supporting the fibrinolytic results. In conclusion, this study demonstrated the thrombolytic potential of the green kiwifruit-derived enzyme and highlighted its potential role as a natural plant-based prophylactic and therapeutic agent for CVDs.

Effects of Green and Gold Kiwifruit Varieties on Antioxidant Neuroprotective Potential in Pigs as a Model for Human Adults.

Kiwifruit (KF) has shown neuroprotective potential in cell-based and rodent models by augmenting the capacity of endogenous antioxidant systems. This study aimed to determine whether KF consumption modulates the antioxidant capacity of plasma and brain tissue in growing pigs. Eighteen male pigs were divided equally into three groups: (1) bread, (2) bread + Actinidia deliciosa cv. 'Hayward' (green-fleshed), and (3) bread + A. chinensis cv. 'Hort16A' (yellow-fleshed). Following consumption of the diets for eight days, plasma and brain tissue (brain stem, corpus striatum, hippocampus, and prefrontal cortex) were collected and measured for biomarkers of antioxidant capacity, enzyme activity, and protein expression assessments. Green KF significantly increased ferric-reducing antioxidant potential (FRAP) in plasma and all brain regions compared with the bread-only diet. Gold KF increased plasma ascorbate concentration and trended towards reducing acetylcholinesterase activity in the brain compared with the bread-only diet. Pearson correlation analysis revealed a significant positive correlation between FRAP in the brain stem, prefrontal cortex, and hippocampus with the total polyphenol concentration of dietary interventions. These findings provide exploratory evidence for the benefits of KF constituents in augmenting the brain's antioxidant capacity that may support neurological homeostasis during oxidative stress.

Dietary fibre intakes of two cohorts of New Zealand adults with and without constipation

Adequate dietary fibre (DF) intake is recommended to relieve constipation and improve gut health(1). It is often assumed that individuals with constipation have relatively low DF intake and do not meet the recommended adequate intake of 25 g and 30 g for females and males, respectively. The 2008/09 New Zealand Adult Nutrition Survey confirmed that the mean DF was 17.9 grams (g) per day for females and 22.8 g per day for males, which was well below the recommended adequate intake(2). With the continuous shift of dietary patterns over time, we sought to compare the current usual DF intake of two cohorts of New Zealand adults: those who have constipation with those without constipation but with relatively low DF intake. We report baseline dietary data from two randomised controlled dietary studies (Kiwifruit Ingestion to Normalise Gut Symptoms (KINGS) (ACTRN12621000621819) and Bread Related Effects on microbiAl Distribution (BREAD) (ACTRN12622000884707)) conducted in Christchurch, New Zealand in 2021 and 2022, respectively. The KINGS study included adults with either functional constipation or constipation-predominant irritable bowel syndrome to consume either two green kiwifruit or maltodextrin for four weeks. The BREAD study is a crossover study and included healthy adults without constipation but with relatively low DF intake (&lt;18 g for females, &lt;22 g for males) to consume two types of bread with different DF content, each bread for four weeks separated by a two-week washout period. All participants completed a non-consecutive three-day food diary at baseline. Dietary data were entered into FoodWorks Online Professional (Xyris Software Australia, 2021) to assess mean daily DF intake. Fifty-six adults from the KINGS study (n = 48 females, n= 8 males; mean age ± standard deviation: 42.8 ± 12.6 years) and BREAD study (n = 33 females, n= 23 males; mean age: 40.4 ± 13.4 years) completed a baseline food diary. In the KINGS study, females with constipation had a daily mean DF intake of 25.0 ± 9.4 g whilst male participants consumed 26.9 ± 5.0 g per day. In the BREAD study, females without constipation had a mean daily DF intake of 19.4 ± 5.8 g, whereas males had 22.6 ± 8.5 g per day. There was a statistically significant difference in the mean daily DF intake between females with constipation and those without constipation (p &lt; 0.001) but not between males (p = 0.19). These two studies found that DF intakes among females with constipation were not as relatively low as previously assumed, as they met their adequate intake of 25 g. Further data analysis from the KINGS and BREAD studies will reveal the effects of using diet to manage constipation and promote better gut health in these two cohorts of New Zealand adults.

Effects of gold and green kiwifruit juices on the physicochemical properties and tenderness of pork loin and antioxidant activity during incubation (24 h) in a pork model system.

Although pork loins is not a tough meat, they need to develop meat products with a soft texture for the elderly. This study focused on the physicochemical properties and tenderness characteristics of pork loin injected with green kiwifruit juice (GRJ) and gold kiwifruit juice (GOJ) during various incubation times. In addition, the antioxidant activities of hydrolysate derived from the hydrolysis of pork loin by kiwifruit juice protease were evaluated. The pork loin was injected with 10% and 20% GRJ and GOJ, under various incubation times (0, 4, 8, and 24 h). Then, the physicochemical properties and tenderness of pork loins were measured. 2,2- diphenyl-1-picrylhydrazyl radical scavenging activity and reducing power were conducted to determine hydrolysate's antioxidant activities derived from pork loin's hydrolysis by kiwifruit juice protease. GRJ had greater tenderizing ability than GOJ, even at the 10% addition. When kiwifruit juice was injected into pork loin, the tenderness increased with increasing incubation time. This was confirmed by the decrease in intensity of the myosin heavy chain (MHC) band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In particular, the MHC band decreased at 8 h for both 10% GRJ and 20% GOJ and at 4 h for 20% GRJ alone. The highest myofibril fragmentation index and peptide solubility were observed in pork loin treated with 20% GRJ compared to the other treatments during incubation. The 10% GRJ and 20% GOJ treatments showed similar levels of antioxidant activity of the protein hydrolysates in pork loin, and 20% GRJ showed the highest activity among the treatments. Kiwifruit juice had protease activity, and GRJ was more useful for tenderizing meat products than GOJ. Thus, GRJ at 10% could be a potential agent to tenderize and enrich the natural antioxidant activity through the proteolysis of pork loin.

Have you tried eating kiwi? Green kiwifruit for functional constipation

Have you tried eating kiwi? Green kiwifruit for functional constipation

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.

Structural Basis of the Immunological Cross-Reactivity between Kiwi and Birch Pollen.

Allergies related to kiwi consumption have become a growing health concern, with their prevalence on the rise. Many of these allergic reactions are attributed to cross-reactivity, particularly with the major allergen found in birch pollen. This cross-reactivity is associated with proteins belonging to the pathogenesis-related class 10 (PR-10) protein family. In our study, we determined the three-dimensional structures of the two PR-10 proteins in gold and green kiwi fruits, Act c 8 and Act d 8, using nuclear magnetic resonance (NMR) spectroscopy. The structures of both kiwi proteins closely resemble the major birch pollen allergen, Bet v 1, providing a molecular explanation for the observed immunological cross-reactivity between kiwi and birch pollen. Compared to Act d 11, however, a kiwi allergen that shares the same architecture as PR-10 proteins, structural differences are apparent. Moreover, despite both Act c 8 and Act d 8 containing multiple cysteine residues, no disulfide bridges are present within their structures. Instead, all the cysteines are accessible on the protein's surface and exposed to the surrounding solvent, where they are available for reactions with components of the natural food matrix. This structural characteristic sets Act c 8 and Act d 8 apart from other kiwi proteins with a high cysteine content. Furthermore, we demonstrate that pyrogallol, the most abundant phenolic compound found in kiwi, binds into the internal cavities of these two proteins, albeit with low affinity. Our research offers a foundation for further studies aimed at understanding allergic reactions associated with this fruit and exploring how interactions with the natural food matrix might be employed to enhance food safety.

Butyrogenic, bifidogenic and slight anti-inflammatory effects of a green kiwifruit powder (Kiwi FFG®) in a human gastrointestinal model simulating mild constipation

Green kiwi (Actinidia deliciosa var. Hayward) is a fruit with important nutritional attributes and traditional use as a laxative. In this work, we studied in vitro the colonic fermentation of a standardized green kiwifruit powder (Kiwi FFG®) using representative intestinal microbial content of mildly constipated women. Static (batch) and dynamic configurations of the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) were used to estimate the impact of Kiwi FFG® in the human gut. Analysis of metabolites revealed a significant butyrogenic effect of the kiwifruit powder and, consistently, butyrate-producing bacterial populations (i.e., Faecalibacterium prausnitzii, Cluster IV, Roseburia spp.) were greatly increased in the dynamic gastrointestinal model. Bifidobacterium spp. was also found boosted in the microflora of ascending and transverse colon sections, and a significant rise of Akkermansia muciniphila was identified in the transverse colon. Reporter gene assays using human intestinal cells (HT-29) showed that kiwifruit fermentation metabolites activate the aryl hydrocarbon receptor (AhR) transcriptional pathway, which is an important regulator of intestinal homeostasis and immunity. Moreover, modulation in the production of human interleukins (IL-6 and IL-10) in Caco-2 cells suggested a potential mild anti-inflammatory effect of the kiwifruit powder and its gut microbiota-derived metabolites. Our results suggested a potential health benefit of Kiwi FFG® in the gut microbiota, particularly in the context of constipated people.

Green and gold kiwifruit powders consumed for 28 days by healthy individuals with occasional constipation are safe and well-tolerated: A randomized controlled trial

Constipation is a global issue which impacts quality of life. Therapeutic laxatives are used to rescue constipation, but they may have side effects such as urgency, gas, bloating or gastrointestinal discomfort. Kiwifruit are thought to promote laxation without the urgency induced by therapeutic laxatives. The objective of this study was to examine the safety and tolerability of a 2,400 mg daily dosage of green kiwifruit powder or gold kiwifruit powder, a 600 mg of green kiwifruit powder or gold kiwifruit powder combined with cellulose, and a combination of 600 mg green kiwifruit powder plus 1,400 mg xylo-oligosaccharide. This randomised, double-blinded, placebo-controlled, parallel study for 28 days across four North American sites (NCT03462199) enrolled 288 participants with non-pathological constipation who had ≤3 complete spontaneous bowel movements (CSBM) per week. Baseline demographics, anthropomorphic and vital signs, clinical chemistry and hematology, and patient assessment of quality-of-life questionnaire, and adverse events data were collected at baseline and end of intervention. All investigational products had no clinically relevant changes to blood chemistry or hematology, and no adverse events linked to the investigational products. However, there were significant (p < 0.05) within-group improvements in patient-assessed quality of life scores in physical discomfort, psychosocial discomfort, worries/concerns, and satisfaction, and overall PAC-QoL scores for all products and placebo. These kiwifruit-derived products were safe and well-tolerated.

The Impact of Kiwifruit Consumption on the Sleep and Recovery of Elite Athletes.

Poor sleep and resultant under-recovery can negatively impact training adaptations, increase the risk of injury and reduce subsequent performance. Due to the 'food first' approach adopted by many athletes, there is scope for investigation of 'functional food' based interventions (i.e., kiwifruit contains melatonin which plays a role in circadian rhythm regulation) designed to promote athlete recovery and/or enhance sleep quality and quantity. Following the baseline assessment (Week 1) all subjects began the intervention (Weeks 2-5). During the 4-week intervention, participants were asked to consume 2 medium-sized green kiwifruit (Actinidia Deliciosa) an hour before bed. Participants completed a questionnaire battery at baseline and post-intervention, and a daily sleep dairy for the duration of the study. The results demonstrated a positive impact of kiwifruit consumption on key aspects of sleep and recovery in elite athletes. From baseline to post-intervention, there were clinically significant improvements in sleep quality (i.e., improved PSQI global scores and sleep quality component scores) and improvements in recovery stress balance (reduced general stress and sports stress scales). Moreover, the intervention improved sleep as evidenced by significant increases in total sleep time and sleep efficiency % and significant reductions in number of awakenings and wake after sleep onset. The findings broadly suggested that kiwifruit does impact positively on sleep and recovery in elite athletes.

A review on various medicinal applications of kiwi fruit

A kiwi fruit commonly known as ‘Green kiwi’ traced under the family Actinidiaceae having Actinidia genus and species deliciosa. Kiwi fruits are the superior as compared with other commonly consumed fruit for their nutrient density, health benefits and consumer’s appeal. It is crammed with wide variety of nutrients such as vitamins, minerals and phytoconstituents. A range of phytochemicals are found in kiwi which include the triterpenoids, saponins, amino acids, carotenoids, carbohydrates and sugars, phenolic compounds such as flavonoids, polyphenols, anthraquinones and coumarins. These constituents render the wide variety of pharmacological activities. Immense amount of vitamin C pointed for a promising treatment of catastrophic disease involving cancer and heart diseases. Other activity includes antibacterial activity, anti-oxidant, anti-diabetic, anti-inflammatory, anti-hypertensive, anti-thrombin, anti-asthmatic, hepatoprotective, anti-platelet, anti-constipation, anti-carcinogenic, anti-fungal, antiviral and anti-tumour. This review provides a brief knowledge about botanical aspects, chemical constituents and recent biological or pharmacological activities of kiwi fruit.

Acute effects of fresh versus dried Hayward green kiwifruit on sleep quality, mood, and sleep-related urinary metabolites in healthy young men with good and poor sleep quality.

Daily kiwifruit (KF) consumption has been associated with improved sleep quality, but underlying physiological mechanisms are unknown. This study examined acute effects of fresh and dried green KF, compared with a water control, on sleep quality, mood, and urinary serotonin and melatonin metabolite concentrations. 24 men (age: 29 ± 1 years, body mass index: 24 ± 1 kg/m2) with poor (n = 12) or good (n = 12) sleep quality participated in a randomized, single-blind crossover study. One of three treatments was consumed with a standardized evening meal; (1) the flesh of two fresh green KF, (2) dried green KF powder (including skin; equivalent to dry matter of two fresh KF) mixed with water, or (3) a water control, in their own home. Subjective and objective sleep quality, mood, waking urinary 5-hydroxyindoleacetic acid (5-HIAA), 6-sulfatoxymelatonin (aMT6s), vitamin C and B-vitamin concentrations were determined. Regardless of sleep quality group, compared to control, morning sleepiness, alertness upon awakening, and vigor were improved (p < 0.05) after dried KF consumption. Compared to control, both fresh and dried KF treatments tended (p < 0.1) toward improved esteem and total mood disturbance. Both KF treatments increased (fresh +1.56 ± 0.4 ng/g, p = 0.001; dried: +1.30 ± 0.4 ng/g, p = 0.004) urinary concentration of the serotonin metabolite 5-HIAA compared to the control (4.32 ± 0.4 ng/g). In poor sleepers, ease of awakening improved by 24% after dried KF consumption (p = 0.005) and tended to improve by 13% after fresh KF intake (p = 0.052) compared to the control. Good sleepers tended toward 9% improved ratings of getting to sleep with fresh KF (p = 0.053) compared to the control. Poor sleepers had lower amounts of some B-vitamins compared to good sleepers (p < 0.05). Consumption of dried or fresh KF with a standard evening meal, was associated with improved aspects of sleep quality and mood, possibly mediated through changes in serotonin metabolism. [www.anzctr.org.au], identifier [ACTRN12621000046808]. Graphical Abstract.

Fermented Gold Kiwi Prevents and Attenuates Chronic Alcohol-Induced Liver Injury in Mice via Suppression of Inflammatory Responses

Excessive alcohol consumption increases the risk of liver disease and liver-related death. Ninety percent of alcohol consumed is broken down in the liver; excessive consumption destroys liver cells and causes stress. The gold kiwi contains more vitamin C than the green kiwi, and various studies have reported that the gold kiwi boosts digestive health. Fermented gold kiwi (FGK) was made using two lactic acids. It contains many more bioactive compounds than fresh gold kiwi. Mice were first given FGK (50, 125, and 250 mg/kg b.w.) and then given a 5 g/kg alcohol solution (50% w/v) for 2 weeks. The results indicate that the FGK promoted hepatic function by significantly decreasing the serum ethanol and aldehyde levels and downgrading the serum TC and TG levels. The FGK attenuated alcohol-induced oxidative stress and improved alcohol metabolism by controlling the ADH and ALDH levels in murine liver tissue. In addition, the FGK significantly reduced the concentration of inflammatory cytokines (TNF-α, IL-1β, and IL-6) in mouse serum and liver tissue. The overexpression of inflammatory mediators (iNOS, COX-2) was also decreased in the FGK groups. This study demonstrates that FGK exerts a protective effect against alcohol-induced liver damage by improving alcohol metabolism and increasing anti-inflammatory activity. This finding suggests that FGK might be developed into a functional food treatment against alcohol-induced liver disease.

Delivery of Catechins from Green Tea Waste in Single- and Double-Layer Liposomes via Their Incorporation into a Functional Green Kiwifruit Juice.

Globally, about one million tonnes of tea products, which contain high concentrations of catechins and their derivatives, are wasted annually. Therefore, green tea waste catechins (GTWCs) are worth extracting, processing, protection, and delivery to the human body. In this study, GTWCs were extracted using a green method and then encapsulated in both single- (SLLs) and double-layer liposomes (DLLs). The encapsulated extracts were subsequently incorporated into a fresh green kiwifruit juice. SLLs and DLLs containing GTWCs had a size of about 180 and 430 nm with a zeta potential of -35 and +25 mV, respectively. Electron microscopy illustrated the separation of the SLLs and fibre in kiwifruit juice and attraction of the DLLs to this fibre. Liposomal GTWCs were effectively maintained in the kiwifruit juice during the 28 days of storage (4 °C), demonstrating the effectiveness of this delivery system for high-value bioactives (i.e., catechins) from such a by-product (i.e., green tea waste).

Effects of Green Kiwifruit Peel Extract on Sleep-Wake Profiles in Mice: A Polysomnographic Study Based on Electroencephalogram and Electromyogram Recordings.

In the previous study, it was reported that green kiwifruit peel ethanol extract (GKPEE) increases sleep duration and decreases sleep latency in pentobarbital-treated mice. The pentobarbital-induced sleep test can be used to verify sleep quantity, which includes factors such as sleep duration and latency, but not sleep quality. In the present study, the sleep-promoting effects of GKPEE were investigated by the analysis of electroencephalogram (EEG) and electromyogram in mice and were compared with the results of diazepam (DZP), a representative sedative-hypnotic agent. The acute administration of GKPEE (250, 500 and 1000 mg/kg) increased the amount of non-rapid eye movement sleep (NREMS) and decreased sleep latency in a dose-dependent manner. The effect of GKPEE at 1000 mg/kg produced persistently significantly different results until the second hour of time-course changes. In particular, GKPEE did not produce any change in delta activity compared to DZP. Furthermore, sub-chronic administration (15 days) of GKPEE (500 mg/kg) continued sleep-promoting effects, whilst the EEG power density of NREMS did not show significant differences, indicating that there were no tolerance phenomena. Our findings suggest that GKPEE may be a promising natural sleep aid for treating sleep disorders. In addition, considering the number of by-products discarded each year by the food industry, the application of GKPEE here contributes to the utilization of processed kiwifruit by-products and can help to solve environmental problems.

Effects of variety, maturity and storage conditions on the allergic potential of kiwifruit and its relationship with antioxidant activity.

This work aimed to study the influences of physiological characteristics (variety, maturity, and fruit components) and storage conditions on the allergenic potential of kiwifruit. The results found kiwifruit allergen (Act d 2) is only measured in the green kiwifruit rather than golden kiwifruit. The Act d 2 content of seed is 2-fold and 4-fold higher than that of pulp and peel, respectively. The highest Act d 2 allergen content was determined in ripe kiwifruit, followed by overripe fruit and unripe fruit. A 50% of enhancement in Act d 2 content was observed after 10-day storage at 20°C. Further, the Act d 2 content showed a negative relationship with the ascorbic acid content and total antioxidant activity at various conditions. Thus, antioxidants as important factors may involve the regulation of Act d 2 in kiwifruit. These findings could provide a deep understanding in the distribution of Act d 2.

Using text highlighting in product research: Case study with kiwifruit in Singapore and Malaysia

Text highlighting is a new method for online sensory-consumer research where participants read a text while making use of highlighting functions to indicate content that they, respectively, ‘like’ and ‘dislike.’ In a recent series of papers, consumers have been found to approach the text highlighting task in a logical and systematic manner, and the results have been shown to deliver attitudinal insights about the focal topic that fit expectations. Building on the early successes of text highlighting, it was an obvious step to try to extend it to applications in product research which occupies a central role in sensory-consumer research. A case study with kiwifruit was performed with consumers in Singapore and Malaysia (n = 1140). Participants read a text (288 words, 19 sentences) which primarily described sensory, nutrition and health characteristics of green and gold kiwifruit. Focusing on 43 specific fruit characteristics, sentiment (difference between the frequency of ‘like’ and ‘dislike’ highlights) was higher for nutrition and health characteristics than for those describing sensory characteristics. Only the Chinese origin of kiwifruit and the hairy skin of green kiwifruit were negatively perceived overall. A novel use of penalty/lift analysis to identify the specific fruit characteristics that significantly influenced expected liking of kiwifruit confirmed the results based on sentiment scores. Moreover, a difference between the drivers of liking for gold and green kiwifruit was identified; the use of ‘like’ highlighting for sensory properties positively contributed to expected liking for gold kiwifruit only. The case study also demonstrated the potential to meaningfully segment consumers based on their highlighting responses to product specific characteristics. The results are discussed in the context of future applications of text highlighting in product research.