Soluble Solids Content Research Articles

Detection of soluble solids content in tomatoes using full transmission Vis-NIR spectroscopy and combinatorial algorithms

IntroductionSoluble solids content (SSC) is an important indicator for evaluating tomato flavor, and general physical and chemical methods are time-consuming and destructive.MethodsThis study utilized full transmittance visible and near infrared (Vis-NIR) spectroscopy for multi-posed data acquisition of tomatoes in different orientations. The role of two directions (Z1 and Z2) and four preprocessing techniques, as well as three wavelength selection methods in the exploitation of SSC regression models was investigated.ResultsAfter using the Outlier elimination method, the spectra acquired in the Z2 direction and the raw spectral data processed by preprocessing methods gave the best result by the PLSR model (Rp = 0.877, RMSEP = 0.417 %). Compared to the model built using the full 2048 spectral wavelengths, the prediction accuracy using 20 wavelengths obtained by a combination wavelength selection: backward variable selection - partial least squares and simulated annealing (BVS-PLS and SA) was further improved (Rp = 0.912, RMSEP = 0.354 %).DiscussionThe findings of this research demonstrate the efficacy of full-transmission visible-near infrared (Vis-NIR) spectroscopy in forecasting SSC of tomatoes, and most importantly, the combination of the packing method in wavelength selection with an intelligent optimization algorithm provides a viable idea for accurately and rapidly assessing the SSC of tomatoes.

Promoting tomato resilience: effects of ascorbic acid and sulfur-treated biochar in saline and non-saline cultivation environments

The resilience of tomato plants under different cultivation environments, particularly saline and non-saline conditions, was investigated by applying various treatments, including 0.5% Ascorbic Acid (AsA) and 1% Sulphur-treated Biochar (BS). The study evaluated parameters such as fruit length, diameter, yield per plant and pot, Total Soluble Solids (TSS) content, chlorophyll content, electrolyte leakage, enzyme activities (Superoxide Dismutase - SOD, Peroxidase - POD, Catalase - CAT), and nutrient content (Nitrogen - N%, Phosphorus - P%, Potassium - K%). Under saline conditions, significant enhancements were observed in fruit characteristics and yield metrics with the application of AsA and BS individually, with the combined treatment yielding the most substantial improvements. Notably, AsA and BS treatments exhibited varying effects on TSS levels, chlorophyll content, electrolyte leakage, and enzyme activities, with the combination treatment consistently demonstrating superior outcomes. Additionally, nutrient content analysis revealed notable increases, particularly under non-saline conditions, with the combined treatment showcasing the most significant enhancements. Overall, the study underscores the potential of AsA and BS treatments in promoting tomato resilience, offering insights into their synergistic effects on multiple physiological and biochemical parameters crucial for plant growth and productivity.

A greener approach to assess bioactive compounds in tropical pumpkin (Cucurbita moschata) using colorimetry

Bioactive compounds have been shown to promote healthy human development and protect against certain diseases including some cancers. Tropical pumpkins bred for consumption, such as calabaza (Cucurbita moschata), possess these compounds, though concentrations vary considerably between varieties. Bioactive compound quantification methods can be expensive, complex, and generate considerable hazardous waste. A predictive tool utilizing the relationship between extrinsic properties and tristimulus colorimetry values of calabaza would allow for significantly higher throughput with lower requirements for equipment, training, and laboratory consumables. Therefore, this study examined correlations between flesh color and bioactive compound quantities of several calabaza germplasm lines to assess the utility of a sustainable and portable predictive tool. CIEL* a* b* values of pumpkin flesh were assessed using a colorimeter and compared to bioactive compound concentrations determined analytically. Redness was found to correlate with increased ascorbic acid and total soluble solids content. Yellowness correlated with β-carotene equivalent carotenoids and ascorbic acid content. These results suggest that colorimetry may be a viable pre-screening technique for quantifying bioactive compounds in C. moschata.

Genetic and QTL analysis of sugars and acids content in sweet cherry (Prunus avium L.)

Abstract Sweet cherry is very appreciated by consumers because of its attractive appearance and taste, which is determined by the balanced sweet-sour flavor. In this work, the genetics of soluble solid content (SSC), titratable acidity (TA), sugars and organic acids was investigated in sweet cherry to facilitate breeding improvement for fruit quality. The fruits of five sweet cherry populations (N = 372), three F1 and two F2, were sampled over two years to evaluate SSC, TA, and the content of individual sugars (glucose, fructose, sorbitol, and sucrose) and organic acids (malic, quinic, oxalic, citric and shikimic) by ultra-performance liquid chromatography (UPLC). Glucose, followed by fructose, was the most abundant sugar, while malic acid was the predominant acid. Sorbitol and malic acid were the most stable compounds between years, and had the highest heritability, being also the best correlated to SSC and TA respectively, revealing their relevance for breeding. Significantly positive correlations were observed among sugars and SSC, and acids and TA, but high interannual variability between years was observed for all traits. QTL mapping for SSC, sugars, TA, and organic acids was performed using a multi-family approach with FlexQTL™. Twenty QTLs were detected consistently during the two phenotyped years, and several relevant regions with overlapping QTLs for sugars and acids were also identified. The results confirmed major stable SSC and TA QTLs on the linkage groups 4 and 6, respectively. Within the main LG4 SSC QTL region, where maturity and fruit development time QTLs have been previously detected, three stable sugar (glucose, sorbitol, and sucrose) and two acid (quinic, shikimic) QTLs were also identified, suggesting a pleiotropic effect of ripening date on the content of these compounds. The major malic acid QTL overlapped with TA QTL on LG6, thus TA QTL mapping in LG6 may correspond to malic acid QTLs. Haplotype analyses of major SSC and sugars QTL in LG4, and TA and malic acid in LG6 revealed haplotypes of breeding interest. Several candidate genes previously identified in other Prunus fruit species, like peach, were found to collocate with the QTLs detected herein. This work reports QTLs regions and haplotypes of sugar and acid content in a Prunus non-climacteric stone fruit for the first time.

Overexpression of SlATG8f gene enhanced autophagy and pollen protection in tomato under heat stress.

Autophagy is a mechanism for the degradation of cellular components in eukaryotes and plays a critical role in plant responses to abiotic stress. As a core member of the autophagy process, ATG8's role in how plants respond to heat stress remains unclear. To investigate the response of the tomato autophagy core member ATG8f to heat stress, we studied the key gene ATG8f and generated tomato lines overexpressing SlATG8f using the recombinant expression vector pBWA(V)HS. We observed that under heat stress, SlATG8f overexpression (OE) plants exhibited decreased heat tolerance compared to wild-type (WT) plants. Specifically, OE plants showed increased relative electrolyte leakage, reduced soluble solid content, elevated chlorophyll content, and higher autophagosome numbers, with less damage to chloroplasts and mitochondria. Additionally, expression of some ATG8 family genes and heat shock protein-related genes was upregulated. Moreover, SlATG8f overexpressing plants had higher pollen vitality and more intact pollen morphology. These results suggest that while SlATG8f overexpression renders plants more sensitive to heat, it helps mitigate high-temperature damage to tomato pollen by maintaining chloroplast integrity and interacting with heat shock proteins to respond to heat stress.

Breeding of new kiwifruit (Actinidia chinensis) cultivars with yellow (golden) fleshed and superior characteristics

The most widely cultivated species globally is Actinidia deliciosa cv. ‘Hayward’. However, in recent years, consumers have shown greater demand for new varieties with novel flesh colour, flavour and appearance in international markets. To meet these expectations, one breeding study was started in 2016 at the University of Guilan in Iran to develop new kiwifruit cultivars with superior characteristics. In this breeding program, 201 female and 534 male hybrid genotypes were obtained from combinations of six different parents using the controlled cross-breeding technique. The evaluations were carried out over three consecutive stages. In the first stage, 201 female hybrid genotypes and control (‘Golden’) were evaluated based on 25 phenological and pomological traits. In the second stage, hybrids passed the desired threshold values in 7 key attributes were selected. Sensory testing in the next stage evaluated these selected hybrid genotypes more. As a result of the first stage, 30 hybrid genotypes with fruit weight (90 ≥ g) were selected. Then, in the second stage, 21 hybrids that showed acceptable dry matter, hue angle, flesh firmness, soluble solid content, acidity, and ascorbic acid were selected. Finally, 13 hybrid genotypes received high scores in sensory testing, and just two hybrid genotypes represented a 100% of novelty with positive texture. These genotypes were selected as potential cultivar candidates. In future studies, fruit yield, disease/pest resistance, and post-harvest performance trials of the 13 selected candidates will be evaluated at different sites. Thus, the ones that give the best results will be introduced to kiwifruit growers.

The Study on Nondestructive Detection Methods for Internal Quality of Korla Fragrant Pears Based on Near-Infrared Spectroscopy and Machine Learning

Quality control and grading of Korla fragrant pears significantly impact their commercial value. Rapid and non-destructive detection of soluble solids content (SSC) and firmness is crucial to improving this. This study proposes a method combining near-infrared spectroscopy (NIRS) with machine learning for the rapid, non-destructive detection of SSC and firmness in Korla pears. By analyzing absorbance in the 900–1800 nm range, six preprocessing methods—Savitzky–Golay derivative (SGD), standard normal variate (SNV), multiplicative scatter correction (MSC), Savitzky–Golay smoothing (SGS), vector normalization (VN), and min-max normalization (MMN)—were applied to the raw spectral data. uninformative variable elimination (UVE) and successive projections algorithm (SPA) were then used to extract effective wavelengths. Partial least squares regression (PLSR) models were developed for SSC and firmness based on the extracted data. The results showed that all preprocessing and wavelength-extraction methods improved model accuracy. The optimal SSC prediction model was MSC-SPA-PLSR (R = 0.93, RMSE = 0.195), and the best hardness prediction model was MSC-UVE-PLSR (R = 0.83, RMSE = 0.249). This research aids in establishing a non-destructive testing system, offering producers a rapid and accurate quality assessment tool, and provides the food industry with better production control measures to enhance standardization and market competitiveness of Korla pears.

Qualitative and quantitative assessment of apple quality using bulk optical properties in combination with machine learning and chemometrics techniques

This study aimed to understand the quantitative relationship between the bulk optical properties (BOP), soluble solids content (SSC), and fruit firmness (FF) of apples, along with the qualitative discrimination of apple cultivar and shelf-life. The absorption coefficient (μa) and reduced scattering coefficient (μs′) of 200 apples from four cultivars during 36-days shelf-life were determined using the single integrating sphere technique in 500-1000 nm. Partial least squares regression (PLSR) and random forest (RF) algorithms were used to establish quantitative prediction models for SSC and FF based on the BOP of apples. The results indicated that the PLSR models based on μɑ and μs′ were optimal for quantitative prediction of SSC (R2p=0.749, RMSEP=0.507) and FF (R2p=0.745, RMSEP=0.571), respectively. RF and linear discriminant analysis (LDA) were used to establish qualitative models for discriminating apple cultivar and shelf-life, demonstrating that the RF model based on μɑ and μɑ+ μs′ had the highest accuracy for the determination of apple cultivar and shelf-life, respectively, with the prediction set reaching 93.2 % and 85.7 %. Overall, RF was better than LDA for qualitative discrimination; however, it was less effective than PLSR for quantitative modeling.

Effects of Tree Spacing and Branch Configuration on Production, Fruit Quality, and Leaf Minerals of ‘Aztec Fuji’ Apple Trees in a Tatura Trellis System Over 5 Years

Tree spacing and branch architecture are critical for the productivity of high-density orchards. The influence of two tree spacings of 45.7 cm × 366 cm and 91.4 cm × 366 cm each with two branch architectures or configurations of shortened branch (ShBr) or overlapped branch (OverBr) on tree growth, yield components, fruit quality, and leaf mineral nutrients in an ‘Aztec Fuji’ apple (Malus domestica Borkh.) orchard with a 60-degree Tatura trellis (V) system was studied over 5 years. Trees planted with 91.4-cm spacing had a significantly greater trunk cross-sectional area (TCSA), higher number of fruit and greater yield per tree, and greater cumulative yield efficiency than those of trees planted with 45.7-cm spacing during 2012–16. Tree spacing did not significantly affect fruit weight and firmness at harvest or after storage. However, trees planted with 91.4-cm spacing always had higher fruit color, sunburn, fruit russet, and watercore at harvest and a higher soluble solids concentration but lower fruit bitter pit at harvest and after storage compared to those of trees with 45.7-cm spacing. These differences were often significant. Trees with 45.7-cm spacing had significantly higher leaf concentrations of potassium, iron, copper, and manganese and relatively higher leaf zinc than those of trees with 91.4-cm spacing. Trees trained according to ShBr architectures had a relatively larger TCSA than those of trees with an OverBr configuration every year. Branching architectures did not affect the number of fruits per tree, yield per tree, yield per hectare, yield efficiency, or biennial bearing index in any year. Trees with a ShBr architecture had significantly larger fruits than those with an OverBr system every year and over the 5 years. Trees with a ShBr architecture had higher average leaf fresh and dry weights and calcium concentration but a similar percentage of dry weight compared to those of trees with an OverBr architecture.

Re-harvest application of 2-(3-chlorophenoxy) propionic acid on pineapple plants

The application of plant regulators such as exogenous auxin may provide effects on the translocation of carbohydrates to plant sinks, which may result in larger parthenocarpic fruits. The objective of the study was to evaluate the effects of the application of 2-(3-chlorophenoxy) propionic acid on the growth and quality of pineapple fruits. The experiment was carried out in a randomized block design. After floral induction, 2-(3-chlorophenoxy) propionic acid (CPA) was applied directly on the inflorescences at the following doses: 0 mg L-1; 40.0 mg L-1; 80.0 mg L-1; 120.0 mg L-1 and 160.0 mg L-1. Growth evaluations continued until 84 days after application, measuring fruit length (cm) with and without crown, crown length (cm), leaf D dry matter, fruit weight with and without crown (g), calculating if also, the absolute and relative growth rates. The post-harvest and quality characteristics of the fruits were also evaluated, as well as the harvest index. The application of CPA significantly reduces the length and weight of the crown of the fruits, however, the exogenous application of auxin provided an increase in the weight of the fruit. Regarding the post-harvest analysis, the application of CPA reduced the content of soluble solids in the fruit pulp.

Cobalt associated with potassium phosphite improves the post-harvest quality of mango cv. Palmer

Mango is a highly perishable climacteric fruit with a short post-harvest period. Therefore, to extend shelf life, the mangoes were treated pre-harvest with a potassium phosphite solution (1.4 g/mL KH2PO4) and a control solution (0 g/mL KH₂PO) associated with different doses of cobalt (0; 48; 64; 80; 112 ml.plant-1) at a density of 1.30 g/mL. The work measured physical, chemical, and biochemical variables. Cobalt and potassium phosphite favored maintaining color and firmness and reduced the respiratory rate. The treatments significantly affected the chemical variables, reduced the soluble solids content, conserved ascorbic acid, and preserved the pH. Foliar application of cobalt and potassium phosphite at pre-harvest is an efficient technique for improving shelf life and maintaining mango quality during storage at room temperature.

Sodium nitroprusside applications modulate cell wall degrading enzymes and preserves the postharvest quality of cold-stored mangoes

ABSTRACT Mango fruit undergoes various physiochemical changes after its harvest that affect consumer acceptability. The present research work was carried out to evaluate the preservation effect of sodium nitroprusside (SNP) treatments on the postharvest quality of mango cv. Langra fruits at 12 ± 1°C for 35 days. The results revealed that SNP 1.0 mM treated fruits exhibited reduced weight loss (6.94%), decay incidence (8.05%), and activities of cell wall degrading enzymes like polygalacturonase and pectin methyl esterase in comparison to uncoated fruits on the last day of storage. Furthermore, the treatment maintained higher fruit firmness (56.77 N) along with fruit quality parameters like soluble solid content (16.24%), titratable acidity (0.20%), starch (4.99%), and, total flavonoid content (12.92 mg/100 g). Overall, SNP 1.0 mM combined with low-temperature storage was proved to be the most effective in extending the shelf life and preserving the quality characteristics of mango fruits.

The preparation of fish scale gelatin-polydopamine photothermal sterilization film and its application for storage of cherry tomato

In this study, polydopamine nanoparticles (PDA NPs) were synthesized and fish scale gelatin (FSG) was extracted by hot water hydrolysis. The film for photothermal sterilization was created by casting FSG with the addition of PDA NPs. The results indicated that the PDA NPs were able to heat up to 46 °C in 5 min under near-infrared (NIR), demonstrating good photothermal conversion. The PDA NPs/FSG solution showed short-term bactericidal activity against Staphylococcus aureus and Escherichia coli, with a bactericidal rate of more than 99 %. The PDA NPs/FSG film could warm up to 42.6 °C under NIR irradiation for 5 min. With the addition of 0.3 % of PDA NPs, the PDA NPs/FSG films showed high UV absorption, DPPH and ABTS radical scavenging ability, and high water contact angle (WCA), improving the barrier to water and oxygen and the tensile strength. The 0.3 % PDA NPs/FSG film triggered by NIR effectively maintained the firmness, soluble solids content and appearance, and delayed the weight loss of cherry tomatoes. Thus, the PDA NPs/FSG films had good photothermal antimicrobial activity and could be used for extending the shelf life of cherry tomatoes.

Synergising tradition and innovation: Fortification of milk kefir with date syrup, a novel functional beverage

AbstractMilk kefir is gaining popularity due to its high probiotic content. This study focuses on fortifying milk kefir with date syrup to enhance its sensory attributes, with the goal of encouraging consumption among the younger generation. Date syrup was added to milk kefir in specific proportions (2, 4, 6, 8, and 10% per 100 mL of milk). The selection of the most suitable percentage (10%, 74 °Bx) was determined based on sensory preferences indicated by the panellists. The newly developed fermented beverage underwent physicochemical and biochemical analyses over a 14-day fermentation period. Results revealed that the addition of date syrup led to a significant (P ≤ 0.001) decrease in pH and total soluble solids (TSS) content, accompanied by a noteworthy increase in total phenolic, flavonoids, condensed tannins contents and antioxidant activity (almost 2-fold). Liquid chromatography - heated electrospray ionisation - mass spectrometry (LC-HESI-MS/MS) results identified the presence of a newly formed and important antifungal compound, p-hydroxyphenyllactic acid (HPLA), showing a progressive increase in quantity during the fermentation process (13.8-fold on the 14th day of fermentation). Hence, the outcomes of this study offer compelling evidence that a novel category of functional beverage can be developed by employing milk kefir as an appropriate starter with the incorporation of date syrup.

Determination of Local Cherry Tomato Genotypes' Agromorphological Features in Türkiye and Kyrgyzstan

The purpose of this study was to ascertain some morphological traits and interrelationships of 36 genotypes of cherry tomatoes that were gathered from Turkey and Kyrgyzstan. Measurements and observations include flower number of cluster, leaf length, leaf width, leaf attitude, fruit color, fruit neck shape, fruit cross-sectional shape, fruit weight, fruit firmness, time of maturity, number of locules, thickness of pericarp, and total soluable solid content, in accordance with the guidelines of the International Union for the Protection of New Varieties of Plants (UPOV). The genotypes T40 (62.7 g), T24 (50.8 g), T107 (50 g), T103 (41.4 g), and T105 (40.8 g) had the highest average fruit weights, whereas T3 (9.4 g) and K1 (10.6 g) had the lowest fruit weights. The pericarp had an average thickness of 3.82 mm and an average of 2.49 locules. A spherical fruit cross-section was observed in 97.2% of genotypes. Genotype K2 had the highest total soluble solids content (TTSC%) at 9.4%, whereas genotype K13 had the lowest TTSC% at 3.1%. To measure the data, Principal Component Analysis (PCA) was used. Five separate principle component axes were identified via PCA, and these axes together account for 75.57% of the dataset's variation. These principal components' eigenvalues, which varied from 1.07 to 3.24, showed how much variance was accounted for by each component. The PCA results showed that the genotypes T107, T40, T105, and T87 performed better in PC1 in terms of the number of locules, fruit weight, fruit cross-sectional shape, and pericarp thickness characteristics. Fruit color was influenced by genotypes T90 and T142, fruit firmness by genotype T40, and total soluble solids content by genotype T98. The indigenous cherry tomato varieties from Turkey and Kyrgyzstan were shown to have a large amount of morphological variety, which may be useful for breeding initiatives in the future.

Effect of Vermicompost Application on the Soil Microbial Community Structure and Fruit Quality in Melon (Cucumis melo)

Melon (Cucumas melon) is widely cultivated and popular because of its quality value and unique flavor. However, the continuous cropping of melons in greenhouses has various negative effects on the soil environment, melon growth, and quality. Recently, farmers have utilized organic fertilization, especially vermicompost, for melons to resist the harmful effects of continuous cropping. A field experiment was conducted to explore the effects of vermicompost on soil microbes and melon fruit quality via high throughput sequencing and chemical sequencing methods. The results showed that the application of vermicompost decreased (p < 0.05) soil pH and increased organic matter, available phosphorus, biomass, urease, catalase, peroxidase, and alkaline phosphatase. A total of 3447 bacterial and 718 fungal operational taxonomic units were identified in all soil samples. Application of vermicompost decreased (p < 0.05) the relative abundances of Acidobacteriota, Gemmatimonadota, Actinobacteriota, and unclassified and increased the relative abundance of Planctomycetota. Compared with the control soil, vermicompost application resulted in significantly higher bacterial Chao indices and a significantly lower Chao index under vermicompost of 60 t ha−1 based on farmers’ normal fertilizer and significantly lower diversity under vermicompost of 90 t ha−1. Otherwise, vermicompost application increased the photosynthetic rate and chlorophyll content of melon leaves and increased the total sugar, soluble solids, vitamin C, soluble protein, and organic acid contents of melon. The results of redundancy analysis indicated that Proteobacteria exhibited a positive correlation with soil ammonium nitrogen (AN) and pH, while showing a negative association with soil available phosphorus and organic matter. Spearman’s correlation analysis revealed that both total sugar content and central soluble solid content in melon had a significant positive correlation (p < 0.05) with Patescibacteria. This study demonstrates that the application of vermicompost alters the microbial community structure in melon cultivation, enhancing fruit quality; this not only promotes a healthier soil ecosystem but also contributes to sustainable and productive practices in melon farming.

Using Legume-Enriched Cover Crops to Improve Grape Yield and Quality in Hillside Vineyards

Natural covering (NATC) has spread on hillside vineyards of central Italy as a replacement for tillage to reduce soil erosion, although it increased nitrogen and water needs. Therefore, in the current context of global warming, using cover crops (CCs) that require less water and provide nitrogen becomes crucial. The effects of two low-competition legume-enriched CCs in a rainfed hillside vineyard—a perennial legume–grass mixture (PLGM) and an annual legume cover crop of Trifolium alexandrinum (ALTA)—were compared with NATC over three years. PLGM and ALTA provided good levels of soil coverage, slightly lower than NATC, which had a negligible presence of legumes. PLGM and ALTA, due to low competition, enhanced vine vigor, resulting in thicker and wider canopies (as indicated by total leaf area and leaf layer number), higher pruning weight, and increased yield. PLGM and ALTA led to good qualitative levels, with higher grapes acidities, lower pH and total soluble solids content and, additionally, significantly higher yeast assimilable nitrogen content. In conclusion, implementing low-competition legume species in CCs is an effective tool to avoid soil erosion in a climate change scenario, leading to increased productivity, higher acidity, and improved nitrogen content in the grapes.

Carvacrol enhances antioxidant activity and slows down cell wall metabolism by maintaining the energy level of 'Guifei' mango.

Postharvest mango fruit are highly susceptible to rapid ripening, softening and senescence, greatly limiting their distribution. In this study, we evaluated the potential effects of carvacrol (0.06 g L-1) on mango (25 ± 1 °C) and the mechanisms by which it regulates antioxidant activity, energy and cell wall metabolism. The results showed that carvacrol treatment delayed the 'Guifei' mango color transformation (from green to yellow) and the decrease in firmness, titratable acidity, weight loss and soluble solids content, and suppressed the increase in relative conductivity, malondialdehyde content and reactive oxygen species (H2O2 and O2 ·-) as well as enhancing antioxidant activity. In addition, carvacrol treatment increased ascorbic acid and reduced glutathione levels, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase and dehydroascorbate reductase activities in mango. Meanwhile, energy level (adenosine triphosphate, adenosine diphosphate, adenosine monophosphate and energy charge) content and energy metabolizing enzyme activities (H+-ATPase, Ca2+-ATPase, succinate dehydrogenasepears and cytochrome C oxidase) were increased on carvacrol treatment, which resulted in the maintenance of higher energy levels. Finally, the application of carvacrol was effective in maintaining firmness and cell wall components by inhibiting the activities of polygalacturonase, cellulase, pectin methyl esterase and β-galactosidase. The current study demonstrates that carvacrol effectively delays the ripening and softening of mangoes by modulating energy metabolism and cell wall dynamics through the attenuation of oxidative stress. © 2024 Society of Chemical Industry.

Estimation of the soluble solid content of citrus based on the fractional-order derivative and optimal band combination algorithm.

The soluble solid content (SSC) is a primary characteristic index for evaluating the internal quality of citrus fruits. The development of rapid and nondestructive SSC detection techniques can help address the current issues of postharvest quality grading in China's citrus industry. In this study, a total of 261 experimental samples, including 70 Murcott, 91 Clementine, and 100 Navel orange, were divided into prediction and validation sets in a 7:3 ratio. After obtaining the reflection spectra and SSCs, SNV-FOD (Standard Normal Variate-Fractional-Order Derivative) was used to process the spectra, and the optimal band combination algorithm was introduced to select SSC-sensitive bands. Then, the obtained optimal dual-band combination was input into eight regression models for comparison, and the best performing models stacked ensemble models was selected. Finally, the H-ELR (HyperOpt-optimized ensemble learning regression) model, optimized using a Bayesian function, was applied for the effective estimation of SSC for three common citrus varieties in Guangxi, Murcott, Clementine, and Navel oranges. The results show that (1) the SNV-FOD preprocessing method proposed in this study improved the correlation coefficient with the SSC from 0.546 to 0.836 compared to that of the original spectrum, (2) the optimal dual-band combination (969 and 1069nm) constructed by integrating the differential index and 1.2-order derivative yielded the most accurate results (RPD=2.13), and (3) the H-ELR model, based on HyperOpt optimization, achieved good estimated performance (RPD=2.46). PRACTICAL APPLICATION: This research contributes to the development of practical SSC prediction instruments with excellent universality and ease of application.

Genome-wide association study of pineapple breeding population

Pineapples (Ananas comosus (L.) Merr.) are one of the most important tropical fruits. Although pineapple breeding program has been conducted in Japan, sufficient genomic information has not been adopted for breeding. The objective of this study was to identify quantitative trait loci (QTL) for pineapple breeding-related traits that can be applied to different populations. Here, we performed a genome-wide association study using seven breeding populations, including 703 individuals with genome-wide 9574 SNPs. Eleven QTLs were detected for nine traits (flesh color, flesh color values (a*, b*), bolting days, days from bolting to harvest, fruit shell color, soluble solid content, acidity, ascorbic acid content, and fruit cracking). Phenotypic value of each genotype in each population was confirmed for each QTL. Six QTLs (acidity QTL ACID-1, ascorbic acid QTL AsA-1 and AsA-2, flesh color QTL FCOL-1 and FCOLb-1, and fruit-cracking QTL CRACK-1) showed significant intergenotypic variance among all populations with genotype segregation. The obtained QTLs and their genotype information will contribute to the selection of cross-breeding parents and marker-assisted selection in pineapple breeding programs.