Peel Color Research Articles

Effect of pre-storage hot air and hot water treatments on post-harvest quality of mango (Mangifera indica Linn.) fruit

Mature, green and fresh mango fruits were harvested from an orchard and sorted before they were subjected to hot air (HA) and hot water (HW) treatments. Before treatment, the fruits were washed with clean water, disinfected for 10 min in 0.385% m/v of sodium hypochlorite and allowed to air-dry at 26 °C before they were separately immersed in HA and HW at 52 and 55 ºC for 1, 3 and 5 min each before storage at 28 ± 2 ºC and 75 ± 5% relative humidity inside sterilized desiccators where the fruit peel colour change was evaluated at intervals of 5days for 20 days while fruits that were not heat treated served as control. Each treatment contained a replicate of five fruits. After 20 days in storage, the heat-treated fruits were then assessed for post-harvest quality characteristics including weight loss, firmness, titratable acidity (TA) and total soluble solids (TSS). Only fruits treated with HA at 52 °C-3 min and 55 °C-3 min retained the mango peel greenness for 20 days while those treated with HW at 55 ºC-1min and 55 ºC-3 min equally retained the peel greenness but for 15 days in storage. Thus, they were considered as effective and interestingly, the weight loss, firmness; TA and TSS of the treated fruits were not significantly affected by these effective treatments as compared with untreated fruits.

Determination of fruit growth and fruit peel and aril colors in different pomegranate genotypes

This study examines the growth of “Kışnarı” genotype with “Hicaznar” and “Kirli Hanım” pomegranate varieties in length and width as well as the fruit peel and seed colors. It was found that the relationship between these genotypes in terms of growth in length and width were positive and significant and that the “Hicaznar” variety grew more robustly than the other two genotypes. The peel L* value was determined to range between 47.15 and 101.00 and varies by year and genotype. The Kışnarı (45.00) variety had the highest a* value in terms of peel color while the highest b* value was registered in the Kirli Hanım (41.88) variety. The fruit peel chromaticity (C*) values varied between 36.99 and 63.51. It was found that the peel color values of the Kirli Hanım (44.88) and Kışnarı (41.59) varieties were significantly higher than those of the Hicaznar (35.14) variety. According to seed L* values, the highest brightness was ascribed to the Kirli Hanım (73.68) while the lowest to the Hicaznar (39.80). According to a two-year average, the a* value of the seed color of the genotypes varied between 39.73 and 47.66. The Hicaznar (18.25) variety had the lowest b* value of seed color while the Kirli Hanım (22.02) had the highest. The seed color chroma (C*) values of the genotypes varied between 43.73 and 53.99. The two-year average seed color H⁰ value of the genotypes varied between 24.48 (Kışnarı) and 25.95 (Kirli Hanım).

Impact of Huanglongbing (HLB) on grapefruit pectin yield and quality during grapefruit maturation

Huanglongbing (HLB) is a plant disease responsible for citrus tree decline, increased fruit drop, and deteriorated fruit quality. Citrus pectin is a billion-dollar industry which may be impacted by the HLB epidemic. We compared the physio-chemical properties of pectin in peel from HLB affected grapefruit collected from open-air trees against healthy grapefruit grown under protective screens (CUPS) at two developmental stages to ascertain HLB impacts on pectin. qPCR detected the causal agent of HLB, which determined if the tested fruit was healthy or non-healthy, and peel color and °Brix defined the fruit's maturity. Depending on the maturity of the HLB affected grapefruit there was between a 16%–25% decrease in pectin yield. HLB affected pectin showed significantly (p < 0.05) increased arabinose, galactose, and in immature HLB affected pectin galacturonic acid sugars, resulting in a lower Homogalacturan/Rhamogalacturan I ratio and a lower degree of branching (DBr) compared to healthy peel pectin. HLB affected pectin had a 7% lower outside degree of methylation (DMoutside) and a 28% decreased degree of blockiness (DB). The DB, absolute degree of blockiness (DBabs), degree of methylesterification (DM), and DMoutside of HLB affected pectin indicates a larger number of non-endopolygalacturonase digestible GalA blocks suggesting HLB affected grapefruit may exhibit a more random methylation pattern. Grapefruit maturation resulted in a 20% increase in pectin yield with a 30% decrease in the pectin molecular weight. Understanding HLB's and fruit maturation impact on pectin will provide customers and manufacturers insight into how these factors impact the industry.

Genome-wide Analysis of MYB Gene Family in Potato Provides Insights into Tissue-specific Regulation of Anthocyanin Biosynthesis

The MYB transcription factor is one of the largest gene families in plants, playing an important role in regulating plant growth, development, response to stress, senescence, and especially the anthocyanin biosynthesis. In this study, A total of 217 MYB genes, including 90 1R-MYBs, 124 R2R3-MYBs, and 3 R1R2R3-MYBs have been identified from the potato genome. The 1R-MYB and R2R3-MYB family members could be divided into 20 and 35 subgroups respectively. Analysis of gene structure and protein motifs revealed that members within the same subgroup presented similar exon/intron and motif organization, further supporting the results of phylogenetic analysis. Potato is an ideal plant to reveal the tissue-specific anthocyanins biosynthesis regulated by MYB, as the anthocyanins could be accumulated in different tissues, showing colorful phenotypes. Five pairs of colored and colorless tissues, stigma, petal, stem, leaf, and tuber flesh, were applied to the transcriptomic analysis. A total of 70 MYB genes were found to be differentially expressed between colored and colorless tissues, and these differentially expressed genes were suspected to regulate the biosynthesis of anthocyanin of different tissues. Co-expression analysis identified numerous potential interactive regulators of anthocyanins biosynthesis, involving 39 MYBs, 24 bHLHs, 2 WD-repeats, and 29 biosynthesis genes. Genome-wide association study (GWAS) of tuber flesh color revealed a major signal at the end of Chromosome 10, which was co-localized with reported I gene (StMYB88), controlling tuber peel color. Analyses of DEGs (Differentially Expression Genes) revealed that both StMYB88 and StMYB89 were closely related to regulating anthocyanin biosynthesis of tuber flesh. This work offers a comprehensive overview of the MYB family in potato and will lay a foundation for the functional validation of these genes in the tissue-specific regulation of anthocyanin biosynthesis.

Some important physicochemical and bioactive characteristics of the main apricot cultivars from Turkey

Turkey is one of the world’s leading producers in both in fresh and dried apricots, and Malatya Province is the capital for apricots. In the present study, the fruit of 13 apricot cultivars (Adilcevaz, Alkaya, Aprikoz, Çataloğlu, Hacıhaliloğlu, Hasanbey, İsmailağa, Kabaaşı, Mahmuduneriği, Soğancı, Şam, Şekerpare, and Tokaloğlu-Erzincan), grown together at the Apricot Research Institute in Malatya Province, were harvested and evaluated for some important physicochemical and bioactive characteristics. The results showed statistically significant differences in most of the physicochemical and bioactive characteristics. Fresh apricot fruit peel color values, L,a, and b, were determined as between 48.66 and 64.70, 8.12and 22.82, and 16.50and 38.67, respectively. The fruit, the dry matter (DM), pH, titratable acidity, reducing sugar, sucrose, total sugar, total phenolic content, lycopene, β-carotene, vitamin A, vitamin E and vitamin C contents were between 13.05% and 23.12%, 3.68 and 5.04, 0.22% and 1.40%, 2.02 and 5.40 g/100 g, 1.83 and 3.97 g/100g, 4.96 and 8.04 g/100 g, 24.60 and 50.69 mg GAE/mg fresh weight, 3.84 and 17.89 mg/100g, 19.59 and 40.53 mg/100g, 0.13 and 0.67 μg/g, 15.67 and 22.12 μg/g, and 1.41 and 8.16 μg/g, respectively. Antioxidant activity was determined using 3 different methods, β-carotene bleaching, trolox equivalent antioxidant capacity (TEAC), and 2,2-Diphenyl-1-picrylhydrazyl hydrate (DPPH). The antioxidant capacity varied according to the methods used. The results showed that apricot fruit had high antioxidant activity and varied according to methods used, and was rich in carotenoids and phenolic substances, which have positive effects on human health and can be consumed as a functional food.

Effects of 1-Methylcyclopropene and Wrapping Material on Postharvest Qualities of Spine Gourd (Momordica dioica)

Spine gourd (Momordica dioica) is a tropical under-utilized vegetable (known as King of Gourds) that belongs to family Cucurbitaceae. It has higher demand in Asia and Sri Lanka due to its distinct taste and promising health properties known for over thousands of years. However, vulnerability to postharvest damages due to climacteric ripening behavior results in short shelf-life of this commodity. It significantly affects their market potential. The present study attempts to extend shelf-life while maintaining postharvest qualities in spine gourd by using 1-methylcyclopropene (1-MCP) and Low-Density Polyethylene (LDPE) wrapping at ambient temperature (27±1 °C). The experiment was conducted according to Completely Randomized Factorial Design using eight treatment combinations: 0, 0.5, 1.0, 1.5 μL L-1 1-MCP treated for 15 hours and stored with and without LDPE wrapping under ambient temperature. Physical parameters; fresh weight loss, firmness, peel color changes and chemical parameters; total soluble solids, titratable acidity were evaluated five days after treatment. Fresh weight loss significantly declined in wrapped spine gourd fruits. The highest firmness was observed in chemically treated fruits with LDPE wrapping. Yellowing of fruits decreased with 0.5 μL L-1 1-MCP and LDPE wrapping. Total soluble solid content was lesser in fruit wrapped with LDPE. Thus, it can be concluded that some postharvest qualities of spine gourd are positively affected by 0.5 μL L-1 1-MCP concentration with LDPE wrapping.

Sensory Quality Evaluation of Korla Pear from Different Orchards and Analysis of Their Primary and Volatile Metabolites.

Metabolites play vital roles in shaping the quality of fresh fruit. In this study, Korla pear fruit harvested from twelve orchards in South Xinjiang, China, were ranked in sensory quality by fuzzy logic sensory evaluation for two consecutive seasons. Then, gas chromatography-mass spectrometry (GC-MS) was applied to determine the primary metabolites and volatile compounds. Sensory evaluation results showed that the panelists were more concerned about ‘mouth feel’ and ‘aroma’ than about ‘fruit size’, ‘fruit shape’ and ‘peel color’. In total, 20 primary metabolites and 100 volatiles were detected in the pear fruit. Hexanal, (E)-2-hexenal, nonanal, d-limonene, (Z)-3-hexen-1-yl acetate and hexyl acetate were identified as the major volatile compounds. Correlation analysis revealed that l-(+)-tartaric acid, hexanoic acid, trans-limonene oxide and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate were negatively correlated with sensory scores. Furthermore, OPLS-DA results indicated that the fruit from three orchards with lower ranks in quality could be distinguished from other samples based on the contents of l-(+)-tartaric acid and other eight metabolites, which were all associated with ‘mouth feel’ and ‘aroma’. This study reveals the metabolites that might be closely associated with the sensory quality attributes of Korla pear, which may provide some clues for promoting the fruit quality in actual production.

Anti-Listeria monocytogenes biofilm mechanism of cold nitrogen plasma

In this study, the anti-L monocytogenes biofilm mechanism of cold nitrogen plasma (CNP) treatment by the generation of reactive oxygen species (ROS) and the changes of gene expression were explored. The treatment of L. monocytogenes (EDG-e, cultured in peptone yeast glucose) biofilm by CNP (600 W, for 220 s, at a gas flow rate of 100 SCCM) led to intracellular oxidative stress where ROS contents increased to 15.38% and the CNP-generated hydroxyl free radicals increased. It also indicated that CNP could activate the environmental response factor (σB) and the expression of sigB was increased by 3.43 times. Real-time PCR revealed that CNP treatment could inhibit the transcription levels of quorum sensing-related genes (agrA, agrB, agrC, agrD, pfs and luxS) and the two pathogenicity island genes (prfA, plcA, hly, actA, plcB, inlA and inlB) in L. monocytogenes. Finally, the application of CNP on cantaloupe preservation indicated that CNP can eliminate the biofilm of L. monocytogenes (approximately 108 CFU/cm2) on cantaloupe by 2–3 log CFU/cm2, thus CNP was proved as a feasible technology to reduce the risk of L. monocytogenes contamination on cantaloupe without affecting the peel color.

‘Valencia Late‘ Portakalının Meyve Kalitesi ve Ağaçta Depolanabilirliği Üzerine Hasat Öncesi Gibberellik Asit Uygulamalarının Etkisi

Bu çalışmada hasat öncesi dönemde gibberillik asit (GA3) uygulamalarının portakal meyvelerinin ağaçta depolama sürecinde dökümlere ve kalite değişimlerine etkilerinin belirlenmesi amaçlanmıştır. Ağaçlara 10 ppm GA3 (renk dönümü öncesi, renk dönümü ve her iki dönem) ve 20 ppm GA3 (renk dönümü öncesi ve renk dönümü) uygulanmış, GA3 uygulanmayan ağaçlar kontrol olarak kabul edilmiştir. Meyveler nisan ayından itibaren aylık periyotlarla beş dönemde hasat edilmiştir. Son hasat döneminde ortalama meyve döküm oranı kontrol grubunda (%38.48), renk dönümü 10 ppm GA3 (%9.44) ve renk dönümü öncesi 20 ppm GA3 (%19.28) uygulamalarına göre belirgin şekilde daha yüksektir. Ağaçta depolamanın ilk iki hasat döneminde meyve dökümü gözlenmemiştir. Ağaçta depolamanın özellikle ilk dönemlerinde kontroldeki portakal meyvelerinin kabuk C* ve h° değerleri, GA3 uygulananlara göre daha yüksek bulunmuştur. Sonuç olarak, iki kez 10 ppm GA3 uygulamasının ‘Valencia Late‘ portakalında hasat öncesi meyve döküm oranını azalttığı, kabuk renk gelişimini geciktirdiği ve meyvelerin kalite değişimini sınırlandırarak ağustos sonuna kadar ağaçta depolanmaya olanak sağladığı açığa çıkarılmıştır.

The Diverse Collection of Exotic Tropical Fruits in The Indonesian Tropical Fruit Research Institute (ITFRI)

Indonesian Tropical Fruit Research Institute (ITFRI) known as an institute collecting exotic tropical fruits in Indonesia. The present study was carried to evaluate the characters of five exotic fruits in the Indonesian Tropical Fruit Research Institute (ITFRI), Solok, West Sumatra, Indonesia. The experiment used field observation. The characters considered were leaf character (leaf shape, leaf margin, leaf tip, leaf base, the color of upper leaf, color of under leaf, leaf surface, leaf length, leaf width), and fruit character (fruit shape, fruit peel texture, fruit length, fruit width, fruit weight, the color of mature peel, the color of mature flesh, taste, fruit weight, seed weight, seed number). Data were analyzed descriptively using tables. The five exotic fruits' morphological characteristics have demonstrated that every species of fruit has specific characteristics. These fruits have the potential to be raw materials for the pharmacy industry.

Developing an Automatic Color Determination Procedure for the Quality Assessment of Mangos (Mangifera indica) Using a CCD Camera and Color Standards

Color is one of the key sensory characteristics in the evaluation of the quality of mangos (Mangifera indica) especially with regard to determining the optimal level of ripeness. However, an objective color determination of entire fruits can be a challenging task. Conventional evaluation methods such as colorimetric or spectrophotometric procedures are primarily limited to a homogenous distribution of the color. Accordingly, a direct assessment of the mango quality with regard to color requires more pronounced color determination procedures. In this study, the color of the peel and the pulp of the mango cultivars “Nam Dokmai”, “Mahachanok”, and “Kent” was evaluated and categorized into various levels of ripeness using a charge-coupled device (CCD) camera in combination with a computer vision system and color standards. The color evaluation process is based on a transformation of the RGB (red, green, and blue) color space values into the HSI (hue, saturation, and intensity) color system and the Natural Color Standard (NCS). The results showed that for pulp color codes, 0560-Y20R and 0560-Y40R can be used as appropriate indicators for the ripeness of the cultivars “Nam Dokmai” and “Mahachanok”. The peels of these two mango cultivars present two distinct colors (1050-Y40R and 1060-Y40R), which can be used to determine the fruit maturity during the post-ripening process. However, in the case of the cultivar “Kent”, peel color detection was not an applicable approach for determining ripeness; thus, the determination of the pulp color with the color code 0550-Y20R gave promising results.

Molecular role of ethylene in fruit r​ipening of Ziziphus jujube Mill

ABSTRACT The fruit of Chinese jujube (Ziziphus jujube) is widely consumed by human beings due to its high proteins, vitamins, and mineral nutrients. The harvest time of Chinese jujube fruit determines its quality, while ethylene plays a pivotal role in fruit ripening. Nevertheless, the relationship between ethylene biosynthesis/signal transduction and fruit ripening of Chinese jujube is still elusive. Here, the Chinese jujube fruit ripening with its fruit peel color change from cyan to dark red at seven different ripening stages (stage I–VII) and expression levels of genes related to ethylene synthesis and signal transduction were determined. Results showed that expression levels of ZjACO1-3, ZjETR2, ZjERF1, and ZjERF4 were increasingly upregulated, whereas the expression levels of ZjERS1, ZjETI, ZjERF2, and ZjERF3 were downregulated from green to red fruit ripening stages. Among them, ZjACO1-3 promoters contain ethylene response element. Taken together, Chinese jujube fruit ripening might be affected by the ethylene signaling which was mainly regulated by ZjACO, a gene involved in ethylene biosynthesis. This research supports theories and techniques for the storage, preservation and molecular breeding of Z. jujube.

Combined Transcriptome and Metabolome analysis of Pitaya fruit unveiled the mechanisms underlying Peel and pulp color formation

BackgroundElucidating the candidate genes and key metabolites responsible for pulp and peel coloration is essential for breeding pitaya fruit with new and improved appeal and high nutritional value. Here, we used transcriptome (RNA-Seq) and metabolome analysis (UPLC-MS/MS) to identify structural and regulatory genes and key metabolites associated with peel and pulp colors in three pitaya fruit types belonging to two different Hylocereus species.ResultOur combined transcriptome and metabolome analyses suggest that the main strategy for obtaining red color is to increase tyrosine content for downstream steps in the betalain pathway. The upregulation of CYP76ADs is proposed as the color-breaking step leading to red or colorless pulp under the regulation by WRKY44 transcription factor. Supported by the differential accumulation of anthocyanin metabolites in red pulped pitaya fruit, our results showed the regulation of anthocyanin biosynthesis pathway in addition to betalain biosynthesis. However, no color-breaking step for the development of anthocyanins in red pulp was observed and no biosynthesis of anthocyanins in white pulp was found. Together, we propose that red pitaya pulp color is under the strict regulation of CYP76ADs by WRKYs and the anthocyanin coexistence with betalains is unneglectable. We ruled out the possibility of yellow peel color formation due to anthocyanins because of no differential regulation of chalcone synthase genes between yellow and green and no detection of naringenin chalcone in the metabolome. Similarly, the no differential regulation of key genes in the carotenoid pathway controlling yellow pigments proposed that the carotenoid pathway is not involved in yellow peel color formation.ConclusionsTogether, our results propose several candidate genes and metabolites controlling a single horticultural attribute i.e. color formation for further functional characterization. This study presents useful genomic resources and information for breeding pitaya fruit with commercially attractive peel and pulp colors. These findings will greatly complement the existing knowledge on the biosynthesis of natural pigments for their applications in food and health industry.

Coffee (Coffea arabica L.) by-Products as a Source of Carotenoids and Phenolic Compounds—Evaluation of Varieties With Different Peel Color

Analysis of pulp and peels of Arabica coffee varieties with different external fruit color allowed the identification of 16 phenolic compounds using high-performance liquid chromatography with diode array detection and electrospray ionization multiple-stage mass spectrometry (HPLC-DAD-ESI-MSn). Nine chlorogenic acids, three flavan-3-ols, the xanthone mangiferin, the flavonol rutin and two anthocyanins were tentatively identified and quantified. 5-O-Caffeoylquinic acid together with a putative (epi)catechin hexoside were the predominant phenolics detected in the coffee varieties analyzed in this work. Whereas 3- and 4-caffeoylquinic acids, as well as 5-O-feruloylquinic acid were consistently found in higher quantities in the pulp than in the peels when individual varieties were compared, the opposite was found for the other phenolic compounds detected. Complementary, GC-MS after alkaline hydrolysis and trimethylsilylation permitted the identification of more than 30 constituents, including phenolic compounds and other benzenoids, caffeine, and diverse carboxylic acids. Detected anthocyanins were cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside. Anthocyanin contents in orange-colored berries were lower than those in red fruits, while no anthocyanins were found in yellow-colored fruit. Among non-anthocyanin pigments, we found β-carotene and lutein in all varieties, along with other chloroplast-specific carotenoids in some accessions. In addition, saponification evidenced the presence of several xanthophyll esters. Both, chlorophyll a and b, were detected in the peels of all varieties, while only chlorophyll b was observed in the pulp. Thus, the color of yellow-peeled varieties is due to carotenoids, while that of orange and red-peeled varieties is due to both carotenoids as well as low and high levels of anthocyanins, respectively. Present results point out to the potential use of by-products of particular coffee varieties with differences in the external fruit color as a source of distinctive bioactive compounds, including anthocyanins and carotenoids, with health benefits.

Dependence of Pepper Fruit Colour on Basic Pigments Ratio and Expression Pattern of Carotenoid and Anthocyanin Biosynthesis Genes

Fruit biochemical analysis of four pepper (Capsicum annuum L.) cultivars, contrasting in immature and ripe fruit colour, was performed, and chlorophylls, carotenoids and anthocyanins were profiled in the peel and pulp during fruit ripening. It was found that pericarp parts (peel and pulp) differ in pigment composition and accumulation mode. In the same fruit tissues, the expression pattern of structural genes of the carotenoid (PSY1, PSY2, LCYb, and CCS) and anthocyanin (CHS, F3 '5 'H, DFR, ANS, and UFGT) pathways was evaluated. It was shown that carotenoid content positively correlates with the PSY1, LCYb and CCS expression level in the fruit pulp and with CCS expression level in the fruit peel. In pepper cultivars with purple-coloured immature fruits (Sirenevyj cub, Otello), a positive correlation was shown between the CHS, F3 '5 'H, DFR, ANS, and UFGT expression levels and the anthocyanin content in the peel. Thus, it was shown that in the pepper fruit, peel and pulp colours are regulated independently and determined by the main pigment ratio and the activity of carotenoid and anthocyanin biosynthesis genes.

Effect of spraying of essential oils and passive modified atmosphere packaging on selected postharvest quality parameters and stem-end rot development in &lt;em&gt;Mangifera indica&lt;em&gt; (cultivar &lt;em&gt;Karthakolomban&lt;/em&gt;)

Mangifera indica L. (cultivar Karthakolomban) is more prone to stem-end rot (SER) disease that causes substantial postharvest losses in quality as well as quantity. The objective of this study was to use aqueous emulsions of basil (1.6 μL/mL), clove (2.0 μL/mL), cinnamon leaf (2.0 μL/mL) and cinnamon bark (1.6 μL/mL) oils as sprays with passive modified atmosphere packaging (MAP) in low density polyethylene (LDPE) bags as a bio-safe strategy to control SER of ‘Karthakolomban’ mango stored at 12 – 14°C and 85 – 90% of relative humidity. Distilled water and 0.1% (w/v) carbendazim 50WP treatments were used as negative and positive controls respectively. In-package respiratory gases were measured during storage for 8 days. Pathological, physicochemical, sensory properties and peel color of mango were assessed after ripening fruits at the end of the storage period. All essential oil treatments combined with passive MAP significantly reduced SER severity of mango more than 93% when compared to the negative control without adversely affecting peel colour and some physicochemical properties like total soluble solids and firmness. Mango fruits treated with basil, clove and cinnamon leaf oils obtained a higher preference by the sensory panel than other treatments. In-package O2 concentration was at 3.8 – 5.8%, while CO2 was at 4.3 – 5.0% at the end of the 8-day storage period. Respiratory gas levels attained a steady state equilibrium which resulted in extending the shelf life. Further, T1, T2 and T3 treatments can be commercialized as eco-friendly treatment strategies to be used during transportation and storage of mango in local trade within one week and for exportation via air cargo that takes approximately 2 – 3 days.

Impact of electron-beam irradiation combined with shellac coating on the suppression of chlorophyll degradation and water loss of lime fruit during storage

The change in the color of the lime peel from green to yellow is the main postharvest-period problem that is unacceptable to consumers. The purpose of this research was to study the effect of electron-beam (E-beam) irradiation and shellac coating on chlorophyll degradation and qualities in lime fruit. Lime fruit cv. Paan were treated with E-beam irradiation at dosages of 0 (control), 0.5 and 1 kGy and stored at 13 °C for 30 d. E-beam treatment at 1 kGy delayed the change in peel color (b* and ΔE values), total chlorophyll content and the increase of chlorophyllase activity more compared to the 0.5 kGy E-beam and control treatments. However, 1 kGy E-beam irradiation increased the respiration rate, resulting in high weight loss. Therefore, shellac coating at 10 % (w/v) applied prior to irradiation with 1 kGy E-beam could minimize the respiration rate and water loss. In addition, shellac coating combined with E-beam irradiation delayed the color change of lime peel (L*, a*, b* and ΔE values), maintained the total chlorophyll content and suppressed the activity of chlorophyll degrading enzymes (chlorophyllase, Mg-dechelatase and pheophytinase) compared to non-treated fruit. However, the combined treatments affected the reduction of titratable acidity and enhanced the accumulation of total ascorbic acid and the hydrogen peroxide (H2O2) content. The results imply that shellac coating combined with E-beam irradiation is an alternative approach to delay chlorophyll degradation and maintain the quality of lime fruit.

Analysis of consumer-oriented quality characteristics of raw and boiled plantains in Cameroon: implication for breeding.

This study aimed at understanding users' demand for raw and boiled plantains in rural and urban areas in West and Littoral regions of Cameroon. Surveys conducted in eight rural localities consisted of key informant interviews, gender-disaggregated focus group discussions, market and individual interviews. Processing and cooking diagnoses were done with restaurant cooks in urban areas, to know the details of plantain processing and boiling and to understand the quality characteristics of raw plantain that give a most-liked boiled plantain. Local favourite landraces, most cultivated landraces in Cameroon (Batard and Big ebanga) and a new CARBAP/CIRAD hybrid (CARBAP K74) were used. The preference for plantain cultivars was both gender and region-dependent. High-quality plantain should be mature, with big fingers and having a dark green peel colour. The fruit length and girth, pulp pH, dry matter content and firmness were found to be relevant postharvest quality characteristics for plantain breeding improvement.

Transcriptome and metabolome analyses reveal the regulation of peel coloration in green, red Chinese prickly ash (Zanthoxylum L.)

Peel colour is an important external economic characteristic of Chinese prickly ash cultivars (Zanthoxylum bungeanum Maxim.). To gain insight into their coloration mechanisms, we performed an integrated analysis of green and red peels using combined metabolomic and transcriptomic analyses. Pelargonin-O-hexoside-O-rhamnoside-O-hexoside, pelargonidin 3,5-diglucoside, peonidin O-hexoside, cyanidin O-syringic acid and peonidin 3-O-glucoside were found to be the key anthocyanins. Transcriptome data indicated that the anthocyanidin synthase genes and UDP-glucose flavonoid 3-O-glucosytransferase genes were significantly increased to promote the redness of the peels. In addition, we discussed the role of R2R3-MYB transcription factors in coloration, of which the c80935 and c226097 genes may be the key regulatory factors for anthocyanin biosynthesis. Generally, this is the first study to identify and reveal the main anthocyanins in Chinese prickly ash peels during different developmental periods. The results of this research lay the foundation for understanding the regulation of coloration in Chinese prickly ash peels.

Correlating the natural color of tropical fruit juice with its pH

AbstractColor analysis is a critical approach used to analyze the quality properties of fruits, particularly in tracing the ripening stage through the peel color of the fruits. In this study, the color features of natural and untreated tropical fruit juice images (ie, B10 Averrhoa carambola L. and Sala mango) were correlated with the pH of the juice samples. The CIELAB color characteristics of the fruits showed that the mango juice had darker features than the carambola juice. The cause may be due to the higher soluble solid content and denser yellow and red pigments in the mango juice. For carambola juice, multiple linear regression (MLR) performed on red‐blue (RB) components generated the best prediction of pH with the highest coefficient of determination and lowest root mean square of error. For mango juice, MLR performed on normalized red‐green‐blue (RGB) components generated the best prediction of pH.