Fruit Flavor Research Articles

Integrated multi-omics analysis provides molecular insights into flavor variation in melons grafted onto two different pumpkin rootstocks during fruit development

Melon fruit flavor is a key quality characteristic that influences consumer preference. Grafting is an effective technique to enhance fruit quality but yields divergent outcomes in terms of fruit flavor. To address this problem, we analyzed parallel changes in flavor-related metabolite accumulation and gene expression in two pumpkin rootstock grafted melons during four fruit developmental stages. We identified 26 061 expressed genes and 840 metabolites from 21 different compound classes, including carbohydrates, amino acids, and lipids. We also detected 50 aroma volatile compounds in the grafted melons. Results showed that genes and metabolites associated with metabolic pathways (carbohydrate, amino acid, lipid, and phenylpropanoid) play a key role in flavor formation. Compared with ‘Sizhuang 12’, ‘Tianzhen 1’ rootstock improved melon fruit flavor by upregulating sugar-related genes (HK, MPI, MIOX, and STP) and inducing metabolite accumulation (d-ribose-5-phosphate, d-galactose, and trehalose 6-phosphate), whereas decreasing bitterness-related amino acids (l-arginine, l-asparagine, and l-tyrosine) and associated genes (thrC, ACS, and GLUL) expression at ripening stage. Furthermore, ‘Tianzhen 1’ exhibited higher expression levels of enzyme-coding genes (4CL, CSE, and COMT) responsible for aroma volatile synthesis than ‘Sizhuang 12’ rootstock. Taken together, our results decipher the basis of the molecular mechanism underlying fruit flavor in grafted melons and provide valuable information for the melons genetic improvement.

Volatile metabolomics and transcriptomics analyses provide insights into the mechanism of volatile changes during fruit development of 'Ehime 38' (Citrus reticulata) and its bud mutant.

Volatile compounds are important determinants affecting fruit flavor. Previous study has identified a bud mutant of 'Ehime 38' (Citrus reticulata) with different volatile profile. However, the volatile changes between WT and MT during fruit development and underlying mechanism remain elusive. In this study, a total of 35 volatile compounds were identified in the pulps of WT and MT at five developmental stages. Both varieties accumulated similar and the highest levels of volatiles at stage S1, and showed a downward trend as the fruit develops. However, the total volatile contents in the pulps of MT were 1.4-2.5 folds higher than those in WT at stages S2-S5, which was mainly due to the increase in the content of d-limonene. Transcriptomic and RT-qPCR analysis revealed that most genes in MEP pathway were positively correlated with the volatile contents, of which DXS1 might mainly contribute to the elevated volatiles accumulation in MT by increasing the flux into the MEP pathway. Moreover, temporal expression analysis indicated that these MEP pathway genes functioned at different developmental stages. This study provided comprehensive volatile metabolomics and transcriptomics characterizations of a citrus mutant during fruit development, which is valuable for fruit flavor improvement in citrus.

Interacting effects of phytohormones and fruit pruning on the morpho-physiological and biochemical attributes of bell pepper

Several factors, such as pruning and phytohormones, have demonstrated an influence on both the quantity and quality in the bell pepper. A factorial experiment using a completely randomized design was conducted on the Lumos yellow bell in a greenhouse. Treatments were the fruit pruning (0, 10, and 30%) and foliar application of phytohormones auxin (AUX) and gibberellic acid (GA3) at concentrations of 10 µM AUX, 10 µM GA3, 10 µM AUX + 10 µM GA3+, and 20 µM AUX + 10 µM GA3 along with controls. The plants were sprayed with phytohormones in four growth stages (1: flowering stage when 50% of the flowers were on the plant, 2: fruiting stage when 50% of the fruits were the size of peas, 3: fruit growth stage when 50% of the fruits had reached 50% of their growth, and 4: ripening stage when 50% of the fruits were at color break). The results of the present investigation showed that pruning rate of 30% yielded the highest flesh thickness and vitamin C content, decreased seed count and hastened fruit ripening. The use of GA3 along with AUX has been observed to augment diverse fruit quality characteristics. According to the results, the application of 10% pruning in combination with 20 µM AUX and 10 µM GA3 demonstrated the most significant levels of carotenoids, chlorophyll, and fruit length. The experimental group subjected to the combined treatment of 30% pruning and 10 µM AUX + 10 µM GA3 showed the most noteworthy levels of vitamin C, fruit weight, and fruit thickness. The groups that received the 10 µM GA3 and 20 µM AUX + 10 µM GA3 treatments exhibited the most favorable fruit flavor. According to the research results, the implementation of hormonal treatments 10 µM AUX and 10 µM AUX + 10 µM GA3 in combination with a 30% pruning strategy resulted in the most advantageous yield of bell peppers.

Impact of biodynamic and organic vineyard management on the microorganism community and aroma characteristics of cabernet sauvignon wine

Researchers and winemakers have recently paid more attention to biodynamic (BDN) and organic (ORG) vineyard management to produce more healthy and regional wines. However, little attention has been paid to the correlation between agricultural systems, microbiota, and wine quality in biodynamic and organic wines in Ningxia, China. In this study, volatiles of wine and microorganism diversities during the wine fermentation using Cabernet Sauvignon grapes from vineyards of biodynamic, non-dynamics (BNDc, i.e., conventional one which was close to BND, considered to be a control of BND), organic, and non-organic (ORGc, i.e., conventional one which was close to BND, considered to be a control of ORG) in Ningxia, China were investigated. Hanseniaspora uvarum, Cladosporium sp., and Alternaria alternata were the main three fungal species, and Lactobacillus kunkeei, Citrus maxima, and Tatumella ptyseos were the main three bacterial species. Surprisingly, BDNc and ORG showed a significantly higher diversity of fungal communities than BDN and ORGc. The network in BDNc was the most complex, with the highest average degree and density and a higher clustering coefficient. Managing biodynamic and organic vineyards could result in floral, herb, spice, and medium floral aromas with low temperate fruit, tropical fruit, and berry flavors to wines. The correlation between agricultural systems, microbiota, and wine sensory systems showed that lactic acid bacteria (Lactobacillus) played critical roles in ORG and BDN by offering pleasant sensory and nutritional benefits. Moreover, Nowamyces globulus, Hanseniaspora uvarum, Lactobacillus johnsonii, Fusarium sp., Microterricola viridarii, Citrus maxima, Sphingomonas faeni, Cladosporium sp., Cladosporium ramotenellum, Cladosporium cladosporioides, Kodamaea ohmeri and Lactobacillus plantarum were positively correlated with aroma compounds. This study improves our understanding of the influence of vineyard management on microorganism succession and wine characteristics, providing a reference and scientific basis for the development of BDN and ORG wines.

Fruit Quality Analysis and Flavor Comprehensive Evaluation of Cherry Tomatoes of Different Colors.

Cherry tomatoes are popular vegetables worldwide owing to their variety of colors and nutrients. However, an integrated evaluation of color and flavor has rarely been reported. This study examined the differences among red, brown, yellow, and green cherry tomatoes grown in the Jiuquan area. A comprehensive analysis of the flavor quality of these tomatoes, including sensory evaluation, electronic nose analysis, nutritional and flavor quality measurements, targeted metabolomics, and chemometrics, was conducted. Red tomatoes had the highest lycopene content, and green tomatoes had the highest soluble protein and vitamin C content. In cherry tomatoes, K is the most abundant macro element and Fe and Zn are the most abundant trace elements. Brown cherry tomatoes had significantly higher K, P, Mg, Cu and Fe contents than other colored tomatoes, and red tomatoes had significantly higher Zn content than other cherry tomatoes (218.8-724.3%). Yellow cherry tomatoes had the highest soluble sugar content, followed by red, brown and green tomatoes. A total of 20 amino acids of tomatoes were simultaneously determined by LC-MS. Yellow cherry tomatoes have the highest content of essential amino acids, aromatic amino acids and sweetness amino acids. Red tomatoes have the highest levels of non-essential and sourness amino acid contents. An analysis of 30 flavor indicators revealed that yellow tomatoes had the best flavor, followed by red, brown, and green tomatoes. Our work lays the foundation for future research on color and flavor formation in cherry tomatoes.

CaC2-induced ripening: Unveiling the bitter truth behind sweet fruit

Fruit ripening is a natural, irreversible process crucial for developing luscious flavor and appealing appearance. Fruits are lauded for their health benefits, forming a key part of a balanced diet. Regrettably, the continued use of calcium carbide (CaC2) to ripen fruit persists in various regions due to its low cost and perceived effectiveness. This method raises significant concerns about health, safety, and the resultant fruit quality and flavor. CaC2 and CaC2-ripened fruits contain harmful substances like inorganic arsenic and phosphorus hydrides, posing considerable health risks including chronic toxicity upon consumption or exposure to acetylene released during CaC2 application. Ensuring food safety requires adherence to regulatory standards governing harmful substances in food. Thus, understanding the risks of consuming CaC2-ripened fruit is crucial for crafting strategies to protect consumers' nutritional well-being and food safety. This review presents a comprehensive analysis of the impacts and apprehensions regarding use of CaC2 as a ripening agent in fresh fruit.

Molecular Regulatory Mechanisms Affecting Fruit Aroma.

Aroma, an important quality characteristic of plant fruits, is produced by volatile organic compounds (VOCs), mainly terpenes, aldehydes, alcohols, esters, ketones, and other secondary metabolites, in plant cells. There are significant differences in the VOC profile of various fruits. The main pathways involved in the synthesis of VOCs are the terpenoid, phenylalanine, and fatty acid biosynthesis pathways, which involve several key enzyme-encoding genes, transcription factors (TFs), and epigenetic factors. This paper reviews the main synthetic pathways of the main volatile components in fruit, summarizes studies on the regulation of aroma formation by key genes and TFs, summarizes the factors affecting the fruit aroma formation, describes relevant studies on the improvement of fruit flavor quality, and finally proposes potential challenges and prospects for future research directions. This study provides a theoretical basis for the further precise control of fruit aroma quality and variety improvement.

Comprehensive Evaluation of Apple Germplasm Genetic Diversity on the Basis of 26 Phenotypic Traits

We used 256 apple germplasm resources for a thorough examination of the genetic diversity associated with 26 phenotypic traits (i.e., genetic diversity analysis, cluster analysis, correlation analysis, principal component analysis, and membership function). The average coefficient of variation for 12 morphological traits was 66.39% (21.10–201.5%). The coefficient of variation was highest and lowest for the fruit arris and the width of the eye basin, respectively. Additionally, the diversity index ranged from 0.54 to 1.33. Moreover, the coefficient of variation for 14 numerical traits varied from 5.37% to 50%. The titratable acid content had the highest coefficient of variation, with a diversity index ranging from 2.01 to 2.08 (average of 2.045). A cluster analysis categorized 256 germplasms into four groups, among which Group I included germplasms with large fruits and the best comprehensive performance. Of the top 10 principal components revealed by the principal component analysis, principal component 1 was mainly related to fruit size and flavor. The top 10 germplasms were selected on the basis of comprehensive scores using the membership function method. Furthermore, a stepwise regression analysis identified 15 key traits for identifying apple germplasms, including the vegetative growth day, fruit weight, and the firmness of the fruit without skin. These results can serve as the foundation for future analyses of the phenotypic diversity of apple germplasms, while also providing a theoretical basis for screening, characterizing, and further improving excellent apple germplasms.

Overexpression of a transcription factor MdWRKY126 altered soluble sugar accumulation in apple and tomato fruit

The compositions and contents of soluble sugars highly determine the flavor and quality of flshy fruits. In the present study, we found that the overexpression of transcription factor MdWRKY126 localized on the nucleus enhanced sucrose concentration while decreased fructose and glucose concentration in transgenic apple calli and ripening tomato fruits. To comprehensively understand the effects of the MdWRKY126 on the content of various soluble sugars in apple and tomato fruits, enzyme activities and related essential genes associated with the sugar metabolism and transportation pathway in MdWRKY126-overrexpressed apple and tomato lines were analyzed. The results indicated that the overexpression of MdWRKY126 upregulated sucrose phosphate synthase (SPS) activity and the gene expression levels of SPS and sucrose transporter SUT, which was conducive to a large accumulation of sucrose in fruit cells. Meanwhile, MdWRKY126 overexpression downregulated the activity of enzymes involved in sucrose decomposition including cell wall invertase (CWINV), sucrose synthase (SUSY) and the corresponding gene expressions, as well as inhibited the expression levels of hexose transporter (HTs) and tonoplast sugar transporter (TSTs) that transport hexose into vacuoles, resulting in a reduced hexose level in apple calli and tomato fruit. These findings enrich our understanding of the metabolism and regulation of soluble sugars in apple fruits.

Integration of transcriptome and metabolome reveals regulatory mechanisms of volatile flavor formation during tomato fruit ripening

Tomato is an important economic crop all over the world. Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality. However, the regulatory mechanism controlling the volatile flavors of tomatoes is still not clear. Here, we integrated the metabolome and transcriptome of the volatile flavors in tomato fruit to explore the regulatory mechanism of volatile flavor formation, using wild and cultivated tomatoes with significant differences in flavors. A total of 35 volatile flavor compounds were identified, based on the solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The content of the volatiles, affecting fruit flavor, significantly increased in the transition from breaker to red ripe fruit stage. Moreover, the total content of the volatiles in wild tomatoes was much higher than that in the cultivated tomatoes. The content variations of all volatile flavors were clustered into 10 groups by hierarchical cluster and Pearson correlation analysis (PCC). The fruit transcriptome was also patterned into 10 groups, with significant variations both from the mature green to breaker fruit stage and from the breaker to red ripe fruit stage. Combining the metabolome and the transcriptome of the same developmental stage of fruits by co-expression analysis, we found that the expression level of 1 182 genes was highly correlated with the content of volatile flavor compounds, thereby constructing two regulatory pathways of important volatile flavors. One pathway is tetrahydrothiazolidine N-hydroxylase (SlTNH1)-dependent, which is regulated by two transcription factors (TFs) from the bHLH and AP2/ERF families, controlling the synthesis of 2-isobutylthiazole in amino acid metabolism. The other is lipoxygenase (SlLOX)-dependent, which is regulated by one TF from the HD-Zip family, controlling the synthesis of hexanal and (Z)-2-heptenal in fatty acid metabolism. Dual-luciferase assay confirmed the binding of bHLH and AP2/ERF to their structural genes. The findings of this study provide new insights into volatile flavor formation in tomato fruit, which can be useful for tomato flavor improvement.

Effects of Pelletized and Coated Organic Fertilizers on Flavor Compounds of Tomato Fruits and Leaves.

The application of organic fertilizers is one of the most important agricultural measures aimed at improving the flavor and productivity of Lycopersicon esculentum, with the granulation and coating of organic fertilizers, which can reduce seepage losses of great significance to the ecosystem. In this study, Jingcai 8 tomato was selected as the test material. Headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) methods were used to investigate the effects of different pelletized organic fertilizers and various coating materials on the flavor profile of the tomatoes. The results indicated that 67 volatile organic compounds (VOCs) were identified in the tomato fruits and 62 volatile compounds were identified in the leaves under different fertilizer treatments. The volatile compound content of the fruits in the BP treatment group was 35.38 μg/g, which was higher than that in other treatment groups, and the volatile compound content of the leaves was lower. A differential compound analysis with log2|fold change| ≥ 1 and variable important in projection (VIP) > 1 highlighted styrene, 3-methyl-1-butanol, and (E, E)-2,4-hexadienal as the major up-regulated compounds and methyl salicylate as the major down-regulated compound in the tomato fruit BCK (control) vs. BP. Moreover, the α-phellandrene content decreased in the tomato leaves. In addition, an analysis of the tomato fruit differential compounds and compounds with odor activity values (OAV) of ≥ 1, considering the OAV values of characteristic aroma compounds, identified key compounds affecting the flavor of the tomato fruits under the BP treatment. These included 2-nonenal, (E)-2-pentylfuran, trans-β-ionone, 1-penten-3-one, (E, E)-2,4-hexadienal, and 3-hexenol (fruity, floral, and herbaceous odors), (E, E)-2,4-heptadienal (fatty odor), and hexanal (green odor). The combined results analysis of the volatile compound content, differential compounds, and OAV values of characteristic aroma compounds aimed to clarify that the BP treatment group, which applied pelletized, large-grain organic fertilizer with polyurethane (pozzolanic + small-grain oil-coated + 2% paraffinic + 4% polyurethane) as a coating material, proved to be most effective in influencing the flavor of the tomato fruits. This finding lays the foundation for its potential commercial application in artificial orchards.

Anti-osteoporosis effect of Prunus humilis fruit on ovariectomized rats via modulating the function of bone metabolism

Prunus humilis Bge. (PH), also known as calcium fruits, is rich in minerals and polyphenols. Given its high content of calcium and other mineral elements, it is believed to be an ideal health fruit to prevent osteoporosis (OP). Hence, the present research aimed to estimate the anti-osteoporotic activity of the fruit of PH in ovariectomized (OVX) rats and to explore the corresponding mechanisms. By utilizing LC-QTOF-MS/MS, 18 primary components, including 14 flavonoids and 4 phospholipids were elucidated in PH. The results of inductively coupled plasma optical emission spectrometry demonstrated that PH exhibited high levels of calcium (1573–1829 mg/kg), phosphorus (1328–1731 mg/kg), and magnesium (897–1027 mg/kg). The pharmacodynamic experiments conducted on OVX rats revealed that continuous oral intervention with PH (10–62.5 mg/kg/day) for three months resulted in significant improvements in both bone mineral density and bone microarchitecture. Meanwhile, the intervention with PH also effectively reversed the bone resorption and formation factors, including type I collagen carboxy-terminal peptide, acid phosphatase 5 tartrate-resistant, deoxypyridinoline, alkaline phosphatase, and procollagen amino-terminal peptide. Additionally, the utilization of LC-QTOF-MS/MS metabolomics revealed the identification of 16 differential metabolites linked to 9 metabolic pathways, all of which were recovered following PH treatment. Furthermore, the protein levels of β-catenin, Wnt1, Sirt1, and FOXO3a were significantly up-regulated after PH intervention, indicating a potential association between the anti-osteoporosis properties of PH and the Wnt/β-catenin and Sirt1/FOXO3a signaling pathways. Our findings provide a new idea for the prevention and treatment of OP through the daily consumption of PH, a sweet and flavorful fruit.

Ultra-high pressure treatment improve the content of characteristic aromatic components of melon juice from the view of physical changes.

The effectiveness of ultra-high pressure (UHP) technology in retaining the flavor of fresh fruit and vegetable juices has been acknowledged in recent years. Along with previously hypothesized conclusions, the improvement in melon juice flavor may be linked to the reduction of its surface tension through UHP. In this paper, the particle size, free-water percentage, and related thermodynamic parameters of melon juice were evaluated in a physical point for a deeper insight. The results showed that the UHP treatment of P2-2 (200 MPa for 20 min) raised the free water percentage by 7,000 times than the other treatments and both the melting enthalpy, binding constant and Gibbs free energy of P2-2 were minimized. This significantly increased the volatility of characteristic aromatic compounds in melon juice, resulting in a 1.2-5 times increase in the content of aromatic compounds in the gas phase of the P2-2 group compared to fresh melon juice.

Transcriptional factor MdESE3 controls fruit acidity by activating genes regulating malic acid content in apple.

Acidity is a key factor controlling fruit flavor and quality. In a previous study, combined transcriptome and methylation analyses identified a P3A-type ATPase from apple (Malus domestica), MdMa11, which regulates vacuolar pH when expressed in Nicotiana benthamiana leaves. In this study, the role of MdMa11 in controlling fruit acidity was verified in apple calli, fruits, and plantlets. In addition, we isolated an APETALA2 domain-containing transcription factor, designated MdESE3, based on yeast one-hybrid (Y1H) screening using the MdMa11 promoter as bait. A subcellular localization assay indicated that MdESE3 localized to the nucleus. Analyses of transgenic apple calli, fruits, and plantlets, as well as tomatoes, demonstrated that MdESE3 enhances fruit acidity and organic acid accumulation. Meanwhile, chromatin immunoprecipitation quantitative PCR, luciferase (LUC) transactivation assays, and GUS reporter assays indicated that MdESE3 could bind to the ethylene-responsive element (ERE; 5'-TTTAAAAT-3') upstream of the MdMa11 transcription start site, thereby activating its expression. Furthermore, MdtDT, MdDTC2, and MdMDH12 expression increased in apple fruits and plantlets overexpressing MdESE3 and decreased in apple fruits and plantlets where MdESE3 was silenced. The ERE was found in MdtDT and MdMDH12 promoters, but not in the MdDTC2 promoter. The Y1H, LUC transactivation assays, and GUS reporter assays indicated that MdESE3 could bind to the MdtDT and MdMDH12 promoters and activate their expression. Our findings provide valuable functional validation of MdESE3 and its role in the transcriptional regulation of MdMa11, MdtDT, and MdMDH12 and malic acid accumulation in apple.

The role of hydrogen-rich water in delaying the pulp breakdown of litchi fruit during postharvest storage

Previous studies have indicated that hydrogen-rich water (HW) treatment can delay fruit ripening and senescence. However, little is known about the HW-delaying pulp breakdown. In this study, eight physiological characteristics revealed that HW treatment delayed both pericarp browning and pulp breakdown of litchi fruit. To gain a comprehensive understanding of the changes in litchi pulp, a combination of multiple metabolomics and gene expression analyses was conducted, assessing 67 primary metabolites, 103 volatiles, 31 amino acids, and 13 crucial metabolite-related genes. Results showed that HW treatment promoted starch degradation, decelerated cell wall degradation and glycolysis, and maintained the flavor and quality of litchi fruit. Furthermore, HW treatment stimulated the production of volatile alcohols, aldehydes, ketones, olefins, and amino acids, which might play a vital role in HW-delaying pulp breakdown. This study sheds light on the mechanism by which HW delayed pulp breakdown by investigating small molecule metabolites and metabolic pathways.

Transcriptional landscape and dynamics involved in sugar and acid accumulation during apple fruit development.

In fleshy fruit, sugars and acids are central components of fruit flavor and quality. To date, the mechanisms underlying transcriptional regulation of sugar and acid during fruit development remain largely unknown. Here, we combined ATAC-seq with RNA-seq to investigate the genome-wide chromatin accessibility and to identify putative transcription factors related to sugar and acid accumulation during apple (Malus domestica) fruit development. By integrating the differentially accessible regions and differentially expressed genes, we generated a global data set of promoter-accessibility and expression-increased genes. Using this strategy, we constructed a transcriptional regulatory network enabling screening for key transcription factors and target genes involved in sugar and acid accumulation. Among these transcription factors, 5 fruit-specific DNA binding with one finger genes were selected to confirm their regulatory effects, and our results showed that they could affect sugar or acid concentration by regulating the expression of sugar or acid metabolism-related genes in apple fruits. Our transcriptional regulatory network provides a suitable platform to identify candidate genes that control sugar and acid accumulation. Meanwhile, our data set will aid in analyzing other characteristics of apple fruit that have not been illuminated previously. Overall, these findings support a better understanding of the regulatory dynamics during apple fruit development and lay a foundation for quality improvement of apple.

Using Eye tracking to Examine Young Adults' Visual Attention to E-cigarette Advertising Features and Associated Positive E-cigarette Perceptions.

Little is known about the influence of e-cigarette marketing features on the antecedents of e-cigarette use. Using an eye-tracking experiment, we examined visual attention to common features in e-cigarette ads and its associations with positive e-cigarette perceptions among young adults. Young adults (ages 18-29) who smoke cigarettes (n = 40) or do not use tobacco (n = 71) viewed 30 e-cigarette ads on a computer screen. Eye-tracking technology measured dwell time (fixation duration) and entry time (time to first fixation) for 14 pre-defined ad features. Participants then completed a survey about perceptions of e-cigarettes shown in the ads. We used regression models to examine the associations between ad features and standardized attention metrics among all participants and by tobacco-use status and person-aggregated standardized attention for each ad feature and positive e-cigarette perceptions. Dwell time was the longest for smoker-targeted claims, positive experience claims, and price promotions. Entry time was the shortest for multiple flavor descriptions, nicotine warnings, and people. Those who do not use tobacco had a longer dwell time for minor sales restrictions and longer entry time for purchasing information than those who smoke. Longer dwell time for multiple flavor descriptions was associated with e-cigarette appeal. A shorter entry time for fruit flavor description was associated with positive e-cigarette-use expectancies. Young adults allocated attention differently to various e-cigarette ad features, and such viewing patterns were largely similar by tobacco-use statuses. Multiple or fruit flavors may be the features that contribute to the positive influence of e-cigarette marketing among young adults.

Extending shelf-life of fresh-cut apples using manna from ash tree (Fraxinus angustifolia) as natural antioxidant agent in comparision with calcium ascorbate

Manna is the sap extracted in summer from the phloem of the stem and the old branches of Fraxinus sp. trees. Its composition is characterized by a high content of D-mannitol, gallic acid, tyrosol and a great antioxidant activity. The aim of the present work was to compare the effect of a solution enriched with manna or calcium ascorbate, the latter widely used by researchers as an antioxidant agent on the control of browning of apple slices. After harvest, apple fruit were cut, treated with manna (MN), calcium ascorbate (CA) or with distilled water as a control (CTR), and packed in polylactic acid (PLA) packaging. Physical, chemical and sensory analyses were performed after 3, 5, 7 and 10 days of storage at 5±0.5 °C. After one week of storage, manna and calcium ascorbate-based treatment significantly inhibited apple fruit slices browning of cut surface, to the same extent, while no significant differences occurred in terms of weight loss, DPPH, total carotenoids and flavor score. On the whole, manna may inhibit apple slices water loss without affecting fruit flavour and providing the maintenance of their shelf-life. It seems that manna and calcium ascorbate mechanism and effect on browning inhibition are very similar and account for maintaining stored apple slices shelf-life up to 7 days. Therefore, our work lays the foundations for the use of manna as a natural antioxidant compound capable of reducing fresh-cut enzymatic browning

Identifying the sensory profiles of naturally fermented table olives and their application to industrially processed cultivars

The study examines the sensory profile of industrially processed, naturally fermented table olives. A detailed set of descriptors crunchiness, hardness, bitter, fibrousness, saltiness, chewiness, sourness, green fruit, ripe fruit, flesh/stone separation, piquant, and musty was developed for green and turning colour Manzanilla and Gordal products, using Quantitative Descriptive Analysis (QDA). Green Gordal (GG) was characterised by higher than average chewiness (scores 7.0–7.1), crunchiness (7.5–8.2), hardness (scores 7.7–8.0) and fibrousness (6.2–6.4). In contrast, turning colour Gordal was lower than average in bitter (2.9–3.4), crunchiness (4.1–4.9), hardness (4.5–5.1) and fibrousness (4.4–4.7). Initially, the green Manzanilla was characterised by higher than average levels of bitter (6.5–7.1), crunchiness (7.2–7.4), hardness (6.9–7.0), and saltiness (3.2–3.3). However, they diminished to about average levels by the end of the fermentation process. The turning colour Manzanilla was initially associated with elevated bitter (5.6–5.9) and lower-than-average final crunchiness (4.6–4.9), hardness (5.1–5.7) and fibrousness (4.5-4.6). However, the final product resulting from this treatment had relatively high significant values for acetic/vinegar (3.5), astringent (3.5), musty (2.0), piquant (2.5), rancid (1.8) and ripe fruit flavour (3.3). The Hotelling T2 test, PCA, and the correlation circle reinforced the specific sensory profile associated with cultivars and maturation stages. Minimal changes were observed over time. PLS-R revealed associations between physicochemical characteristics and sensory profiles such as bitter with phenol content (standardised coefficient; 0.881) and texture (0.755) or ripe fruit with bitter index (0.475), among others.

Using Mutation Breeding to Improve the Eating Characteristics of the Fusarium Wilt-Resistant Banana Variety, ‘Goldfinger’ (AAAB)

Banana production in Australia is under threat from Fusarium wilt Tropical Race 4 (TR4), and the option of growing a disease-resistant variety is sought after by many farmers. Goldfinger is one such alternative; however, it was previously rejected by Australian consumers. In Phase I of this investigation, mutagenesis was employed as a practical method to generate large numbers of novel variants. In Phase II, 631 variants were established in a field trial where agronomic and postharvest assessments, including taste-testing, identified 20 improved selections. Phase III involved a replicated field evaluation of the selections with favourable mutations, where further taste-testing revealed five selections with the most promising eating characteristics. In Phase IV, the five selections underwent large-scale consumer and sensory evaluations where four of them performed as well as the industry standard controls ‘Williams’ Cavendish and Lady Finger. The sensory analysis revealed differences in the fruit flavour profile and textural attributes, and these features will play a key role in bringing a new banana variety to market and for promotion to consumers. Screening of the variants’ resistance to yellow Sigatoka was integrated into the project, but further work is needed to ensure these four selections have retained their TR4 resistance.