Soluble Solids Content Research Articles

Exploring Near-Infrared and Raman Spectroscopies for the Non-Destructive In-Situ Estimation of Sweetness in Half Watermelons

Watermelons are in high demand for their juicy texture and sweetness, which is linked to their soluble solids content (SSC). Traditionally, watermelons have been sold as whole fruits. However, the decline in the mean size of households and the very large size of the fruits, together with high prices, mainly at the beginning of the season, mean that supermarkets now sell them as half fruits. For consumers, it is important to know in advance that the fruits that they are purchasing are of a high quality, based not only on external flesh colour but also on sweetness. Near-infrared spectroscopy (NIRS) and Raman spectroscopy were used for the in situ determination of SSC in half watermelons while simulating supermarket conditions. A handheld linear variable filter (LVF) device and an all-in-one (AIO) Process Raman analyser were used for the NIRS and Raman analysis, respectively. The excellent results obtained—including residual predictive deviation for prediction (RPDp) values of 3.06 and 2.90 for NIRS and Raman, respectively—showed the viability of NIRS and Raman spectroscopies for the prediction of sweetness in half watermelons.

First Results of Management of Powdery Mildew in Grapevine Using Sulphur, Silicate and Equisetum arvense Formulations

The management of grapevine from diseases is now particularly focused on the development of environmentally friendly strategies. Although sulphur is not in itself a toxic substance, its extensive use in powdery mildew, in organic vineyards especially, may cause environmental problems and plant phytotoxicity and affect the health and safety of viticultural workers. The activity of sulphur applied at doses reduced up to 50% in tank mixtures with silicates or in Equisetum arvense-based products was assessed on powdery mildew in grapevine. Two-year trials were carried out applying the products every 7–10 days in the period of greatest risk for disease infections, in two organic vineyards in the Abruzzo region, Italy. In both vineyards throughout all trial years, at harvest, disease incidence and severity on leaves and bunches in the silicon + sulphur treatments were generally significantly lower compared to both the sulphur at full dose and to the control. In all trials, in both vineyards, a strong activity of silicon + sulphur mixtures towards disease on leaves was observed. This effect could be decisive in lowering the potential inoculum in the following season. In the Ari vineyard, vines treated with the mixtures always increased yield quantity and quality, given the higher contents of soluble solids and lower levels of total acidity. In the Cellino vineyard, probably due to the young age of the vines, increases in yield quantity were observed, with lesser effects on quality. The promising activity of the mixtures needs further studies to confirm these positive results. Furthermore, in both vineyards, the source of primary inoculum of the pathogen was observed as chasmothecia on the leaves.

Epistasis between genetic variations on MdMYB109 and MdHXK1 exerts a large effect on sugar content in apple fruit.

Many quantitative traits are controlled by multiple genetic variations with minor effects, making it challenging to resolve the underlying genetic network and to apply functional markers in breeding. Affected by up to a hundred quantitative trait loci (QTLs), fruit-soluble sugar content is one of the most complex quantitative traits in apple (Malus sp.). Here, QTLs for apple fruit sucrose and fructose content were identified via QTL mapping and bulked-segregant analysis sequencing (BSA-seq) using a population derived from a 'Jonathan' × 'Golden Delicious' cross. Allelic variations and non-allelic interactions were validated in the candidate genes within these defined QTL regions. Three single-nucleotide polymorphisms (SNPs) (SNP -326 C/T, SNP -705 A/G, and SNP -706 G/T) in the MdMYB109 promoter region affected the binding ability of the repressive transcription factor MdWRKY33, leading to increased MdMYB109 expression. MdMYB109 bound directly to the promoter of the sucrose transporter gene MdSUT2.2 and activated its expression, raising fruit sucrose content. A SNP (SNP1060 A/G) in the hexokinase gene MdHXK1 affected the phosphorylation of the transcription factor MdbHLH3, and phosphorylated MdbHLH3 interacted with MdMYB109 to co-activate MdSUT2.2 expression and increase fruit sucrose content. Adding the joint effects of the genotype combinations at the SNP markers based on the SNPs in MdMYB109 and MdHXK1 increased the prediction accuracy of a genomics-assisted prediction (GAP) model for total soluble solid content from 0.3758 to 0.5531. These results uncovered functional variations in MdMYB109 and MdHXK1 regulating apple fruit sucrose content. The updated GAP model with improved predictability can be used efficiently in apple breeding.

Detection of Pear Quality Using Hyperspectral Imaging Technology and Machine Learning Analysis

The non-destructive detection of fruit quality is indispensable in the agricultural and food industries. This study aimed to explore the application of hyperspectral imaging (HSI) technology, combined with machine learning, for a quality assessment of pears, so as to provide an efficient technical method. Six varieties of pears were used for inspection, including ‘Sucui No.1’, ‘Zaojinxiang’, ‘Huangguan’, ‘Akizuki’, ‘Yali’, and ‘Hongli No.1’. Spectral data within the 398~1004 nm wavelength range were analyzed to compare the predictive performance of the Least Squares Support Vector Machine (LS-SVM) models on various quality parameters, using different preprocessing methods and the selected feature wavelengths. The results indicated that the combination of Fast Detrend-Standard Normal Variate (FD-SNV) preprocessing and Competitive Adaptive Reweighted Sampling (CARS)-selected feature wavelengths yielded the best improvement in model predictive ability for forecasting key quality parameters such as firmness, soluble solids content (SSC), pH, color, and maturity degree. They could enhance the predictive capability and reduce computational complexity. Furthermore, in order to construct a quality prediction model, integrating hyperspectral data from six pear varieties resulted in an RPD (Ratio of Performance to Deviation) exceeding 2.0 for all the quality parameters, indicating that increasing the fruit sample size and variety number further strengthened the robustness of the model. The Backpropagation Neural Network (BPNN) model could accurately distinguish six distinct pear varieties, achieving prediction accuracies of above 99% for both the calibration and test sets. In summary, the combination of HSI and machine learning models enabled an efficient, rapid, and non-destructive detection of pear quality and provided a practical value for quality control and the commercial processing of pears.

Integrative transcriptome and metabolome analyses reveal the mechanism of melatonin in delaying postharvest senescence in cowpeas

Rapid postharvest senescence and quality deterioration severely limit logistics of cowpeas. Melatonin (MEL) is a pivotal bioactive molecule that can modulate multiple physiological attributes in plants. In this study, physiological, transcriptomic and metabolomic analyses were conducted to explore the effects of exogenous MEL on cowpea senescence and its underlying mechanisms. Physiological results showed that 100 μM MEL treatment maintained sensory quality (greeness, firmness and soluble solids content), reduced weight loss as well as inhibited the degradation of chlorophyll (Chl) and protopectin. Preservation of color and firmness in cowpeas was greatly attributed to inhibition of expression of genes related to Chl and cell wall metabolism, which was based on a transcriptomic analysis. Integrated transcriptomic and metabolomic analyses revealed that MEL promoted transcription of genes associated with amino acid and carbohydrate metabolism, resulting in the accumulation of amino acid and sugar metabolites. Additionally, by integrating transcription factor-binding site analysis with cis-acting element analysis, we constructed a regulatory network of transcription factors underlying MEL-mediated antisenescence. The present study found a series of potential candidate genes and metabolites involved in regulating senescence process and provided an insight into improving postharvest quality of cowpeas.

Effect of Different Light Intensities on the Quality of ‘Korla’ Fragrant Pear Fruits

This study aimed to investigate the effect of different light intensities on the quality of ‘Korla’ fragrant pear fruits. The differences in fruit quality were determined by evaluating the pigment content and fluorescent characteristics of the peel. The date of fruit weight, aspect ratio, soluble sugar content, soluble solid content, reducing sugar content, and vitamin C content of fruits, were higher under 100% light intensity than in shade treatment. However, firmness of the peel and pulp, and titratable acid content were enhanced in shade-treatment. Total chlorophyll, Chl a, and Chl b contents gradually decreased with the reduction in light intensity. The anthocyanin content gradually decreased with the decrease in light intensity. The maximum photochemical efficiency (FV/FM) of PSII significantly declined at 1% light intensity. As the light intensity decreased, the actual fluorescence quantum efficiency of PSII (F′V/F′M), non-photochemical quenching (NPQ), and actual photochemical efficiency of PSII (ΦPS II) progressively decreased. The results indicate that photoinhibition occurred in the peel of fragrant pear fruits. Shade treatment reduced the intrinsic quality of ‘Korla’ fragrant pear fruits, whereas a moderate decrease in light intensity could enhance the extrinsic quality of fruits.

Systematic review of artificial intelligence with near-infrared in blueberries

The fruit quality has a direct impact on how the fruit looks and how tasty the fruit is. The correct use of tools to determine fruit quality is essential to offer the best product for the final consumer. This study has used the preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology. The study objective was elaborate a systematic literature review (SLR) about research of the application of techniques based on artificial intelligence to analyze indicators obtained by near infrared spectroscopy (NIRS) and chemometrics to determine the quality of fruits, including blueberries. The most frequently addressed indicator is the soluble solids concentration (SSC) which was used in several studies with techniques such as support vector machines (SVM) and convolutional neural networks (CNN). According to the results obtained, it is possible to use these techniques to predict blueberry quality indicators. There was an acceptable performance and high accuracy of these models. However, future research could cover other techniques and help to provide better quality control of products in food industries.

Melatonin maintains the quality and cell wall structure of plum fruits under low temperature storage

To enhance the quality of plum fruits under low temperature storage, the impact of melatonin (MT) treatment (100 μmol L−1) on the quality and cell wall structure of plum fruits under low temperature storage (at 4 °C for 28 days) was examined. The results showed that the contents of total soluble solids, total sugar, titratable acid, and vitamin C in plum fruits treated with MT were higher than control under low temperature storage, and MT helped to prevent pulp browning and maintained the overall quality of the fruits. In addition, MT inhibited the conversion of ion-binding pectin and covalently-bound pectin of plum fruits into water-soluble pectin under low temperature storage. It also decreased the activities of pectin methylesterase, polygalacturonase, β-galactosidase, and endo-β-1, 4-glucanase, while increasing the activities of xyloglucan endotransglycosylase/hydrolase and α-l-arabinofuranosidase. Correlation analysis showed that the fruit hardness and pulp hardness were positively correlated with the covalently-bound pectin content, hemicellulose content, and cellulose content, and negatively correlated with the water-soluble pectin content, ion-binding pectin content, pectin methylesterase activity, β-galactosidase activity, and endo-β-1, 4-glucanase activity. Moreover, the cell structure of plum fruits treated with MT remained more intact and tightly arranged under low temperature storage, with slower degradation of the middle lamella and higher cell wall thickness. This was beneficial for maintaining the integrity of the cell wall structure and inhibiting the increase of intercellular spaces. In conclusion, MT can maintain the quality and cell wall structure of plum fruits, inhibit cell wall degradation, and slow down the decrease in fruit hardness under low temperature storage.

Osmo hydrocolloid assisted dehydration of onion slices: Effect on Bioactive Components, Rehydration, Microstructure

The present study aimed to develop pretreatments and dehydration strategies for onions to retain the structure so that improved rehydration could be achieved with better quality attributes and shelf life. Effect of osmotic treatment at NaCl concentrations of 5, 10, 15 and 20 % for the duration of 60, 120, and 180 min and hydrocolloid coating (5, 10, 15 and 20%) on onion slices was studied. Osmotic pretreatments with 10% NaCl for 120 min followed by dipping in 5% gum Arabic solution were found optimum in increasing the total soluble solids content in onion slices for further effective dehydration. The pretreated onions were dried at temperatures of 50, 60, and 70°C using a tray dryer (air velocity of ∼1.5 m/s), drying kinetics and dried onion quality were evaluated. The results revealed that osmotic pretreatment and higher drying temperatures significantly increased the drying rate and decreased drying time for onion slices. However, the drying temperature of 60°C was optimum for reducing the drying time with better retention of ascorbic acid (62%), and pyruvic acid (77%) with a nearly 2-fold increase in total phenolics and total flavonoids compared to fresh onions. A positive change in color attributes and rehydration ratio was observed for osmo-hydrocolloid-treated and dried onion slices. Scanning electron microscopic images of fresh onion slices showed elongated well-arranged cells whereas in dried onions, cell walls were disrupted due to the sudden expulsion of moisture from the onion cells. The microstructure of osmo-hydrocolloid pretreated and dried onion cells showed less structural damage due to the protective effect of hydrocolloid coating and an increase in the solid content during osmotic treatment. Prospects of the current research could focus on exploring different hydrocolloids with innovative drying techniques to further enhance the nutritional and structural retention in dehydrated onions and the potential application of these strategies to other vegetables.

Preparation And Evaluation Of A Mixed Vegetable Drink Based On Coconut Milk, Amaranth, Quinoa And Acerola

Allergic substances present in food pose a great risk to an individual's nutrition and health, depriving them of nutrients due to food restrictions. The vegetable drink made with coconut milk, amaranth, quinoa and acerola pulp (BVCAQA) could become a healthy and innovative drink, since the simplicity of the product's composition and the absence of additives allow it to be used as a nutritious, functional and hypoallergenic food. Formulations were made without the addition of acerola pulp (A) and with the addition of acerola pulp (B). The physicalchemical analyses followed the Adolfo Lutz Institute's physical-chemical methods for food analysis and the microbiological analyses followed the Manual of methods for microbiological analysis in food. In order to check whether there were any significant differences, the Analysis of Variance (ANOVA) was applied using the SISVAR program version 5.6. Principal Component Analysis (PCA) was carried out using the PAST software. The vegetable drink based on coconut milk, amaranth, quinoa and acerola pulp was produced naturally, without stabilizers, thickeners or industrial emulsifiers. There was a significant difference (p<0.05) between formulations A and B for the physicochemical parameter’s soluble solids, pH and humidity. The acerola pulp is acidic and has a high moisture content. Its addition helps to reduce the pH and increase the moisture and soluble solids content of the vegetable drink. Its production could be a feasible technological possibility for small manufacturers. The hygienic and sanitary procedures used in the production of the vegetable drink contributed to its safety and the absence of microbiological contamination. The coconut, amaranth and quinoa drink flavored with acerola pulp could be a viable alternative for people looking for a balanced, nutritious diet or people who are lactose intolerant or allergic to animal milk and soy proteins

Propagation, Establishment, and Early Fruit Production of Table Grape Microvines in an LED-Lit Hydroponics System: A Demonstration Case Study.

Controlled environment farming (CEF) systems, including tunnel houses, glasshouses, and vertical farms, are expanding worldwide. As the industry scales, growers need a broader range of crops that are adapted to CEF systems to take full advantage of the potential to increase yields and decrease weather-related risks. Dwarf grapevines (microvines) are ideal candidates for CEF due to their high economic value, phenotype, and phenology. This study aimed to develop propagation protocols, a critical first step for the successful integration of microvines in the CEF market, and to demonstrate the establishment, early growth, first flowering, and fruiting of table grape microvines in a fully indoor, LED-lit, CEF system. An experiment was conducted to investigate the efficiency of clonal propagation of a newly developed microvine variety, which had been bred for the production of seedless table grapes in response to two variables: (a) shoot position of cutting, and (b) length of time of misting exposure (from 3 to 7 weeks). A subset of successfully established plantlets were then transplanted into a hydroponic, CEF system, where their establishment, early growth, flowering, and fruit formation were assessed. Three weeks after cuttings were taken, 83.7% of the cuttings had formed roots, regardless of cutting section or misting treatment, while the remaining 16.7% of cuttings died. The sprouting success was lower with 49.3% of plants forming new leaves after 7 weeks. The highest level of sprouting was observed with cuttings taken from mid-shoot and lower shoot positions and the 5-week misting duration. While the rooting efficiency and survival of green shoot microvine cuttings are very high, further research is needed to increase the frequency of sprouting in the required timeframes to levels that are more acceptable for commercial production. The establishment success of sprouted cuttings after transplanting to hydroponics was 100% and their production and fruit quality were similar regardless of cutting tissue source. The crop cycle from planting to first harvest was 208 days (63 days for plantlet production and 145 days from transplanting to first harvest). The vines began flowering after an average of 33.9 days and the berries went through veraison (i.e., commencement of ripening) after an average of 116 days under the conditions tested. Microvine fruit grown under these conditions contained greater than the minimum total soluble solids content required for the Australian market. We have demonstrated that table grape microvines have potential as a novel crop for CEF systems.

Exploring the potential of wild date palm (Phoenix Sylvestris L. Roxb) fruits for vinegar production in Bangladesh

The wild date palm (Phoenix Sylvestris L. Roxb), indigenous to Bangladesh, remains underutilized for creating consumable products. This study explores the potential of wild date palm fruit as a valuable food ingredient by converting its juice into vinegar through a two-step fermentation process. Juices with varying total soluble solids (TSS) concentrations of 10%, 15%, 20%, and 25% were subjected to sequential alcoholic and acetic acid fermentation, yielding four vinegar samples (S1, S2, S3, and S4, respectively). During anaerobic fermentation with Saccharomyces cerevisiae, results indicated a significant increase in alcohol content and a corresponding decrease in pH (p ≤ 0.05) with rising TSS levels. Subsequent acetic fermentation utilizing Acetobacter species converted the alcohol into acetic acid, with the 25% TSS vinegar demonstrating the highest nutritional value, acidity, residual reducing sugar, alcohol content, and macro minerals (K, Ca, P, Mg, Na) among the samples. Additionally, increased TSS resulted in a significant rise in density and a decrease in electrical conductivity and linear color change (p ≤ 0.05). All vinegar samples exhibited notable total phenolic content and free radical scavenging capacity. This study underscores the potential of wild date palm fruits in producing high-quality vinegar, offering a novel utilization avenue for this indigenous resource.

Evaluation of White Onion (Allium cepa L.) Genotypes for Growth, Yield, Quality and Resistance to Thrips and Purple Blotch Disease

Onion (Allium cepa L.), belonging to the family Alliaceae with a chromosome number 2n=16, is an essential vegetable widely cultivated for both domestic consumption and export. This study aimed to evaluate various white onion genotypes for their growth, yield, quality and resistance to pests and diseases. The experiment was conducted at the Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, during the late Kharif season of 2023-24, using twenty-six genotypes arranged in a randomized complete block design. Data were collected on several growth and yield parameters, which were then analyzed. Significant variation was observed among genotypes for growth traits such as plant height, leaf length and neck diameter. The genotype 'Safed Ghavriyu' exhibited the highest plant height and number of leaves per plant, while 'Bhima Shubra' and 'Milky White' showed superior leaf length and neck diameter, respectively. Yield-related traits also varied significantly, with 'Bhima Shweta' recording the highest dry matter content and 'Safed Ghavriyu' demonstrating the highest fresh and dry weight per plant, single bulb weight and total yield per hectare. In terms of pest and disease resistance, notable differences were observed, with 'Safed Ghavriyu' showing the lowest incidence of thrips and purple blotch disease. Additionally, 'PWO-2' had the highest total soluble solids (TSS) content, while 'W-210' had the highest total sugar content. 'Milky White' exhibited the highest pyruvic acid content, contributing to its pungency. These findings underscore the significance of genetic variability and environmental influences in white onion growth and yield. The results offer valuable insights for the development of high-yielding, disease-resistant white onion varieties suited to various agro-climatic conditions in India.

VIS/NIR Spectroscopy as a Non-Destructive Method for Evaluation of Quality Parameters of Three Bell Pepper Varieties Based on Soft Computing Methods

Spectroscopic analysis was employed to evaluate the quality of three bell pepper varieties within the 350–1150 nm wavelength range. Quality parameters such as firmness, pH, soluble solids content, titratable acids, vitamin C, total phenols, and anthocyanins were measured. To enhance data reliability, principal component analysis (PCA) was used to identify and remove outliers. Raw spectral data were initially modeled using partial least squares regression (PLSR). To optimize wavelength selection, support vector machines (SVMs) were combined with genetic algorithms (GAs), particle swarm optimization (PSO), ant colony optimization (ACO), and imperial competitive algorithm (ICA). The most effective wavelength selection method was subsequently used for further analysis. Three modeling techniques—PLSR, multiple linear regression (MLR), and artificial neural networks (ANNs)—were applied to the selected wavelengths. PLSR analysis of raw data yielded a maximum R2 value of 0.98 for red pepper pH, while the lowest R2 (0.58) was observed for total phenols in yellow peppers. SVM-PSO was determined to be the optimal wavelength selection algorithm based on ratio of performance to deviation (RPD), root mean square error (RMSE), and correlation values. An average of 15 effective wavelengths were identified using this combined approach. Model performance was evaluated using root mean square error of cross-validation and coefficient of determination (R2). ANN consistently outperformed MLR and PLSR in predicting firmness, pH, soluble solids content, titratable acids, vitamin C, total phenols, and anthocyanins for all three varieties. R2 values for the ANN model ranged from 0.94 to 1.00, demonstrating its superior predictive capability. Based on these results, ANN is recommended as the most suitable method for evaluating the quality parameters of bell peppers using spectroscopic data.

Physicochemical Factors Affecting the Rheology and Stability of Peach Puree Dispersions

The rheological properties and sedimentation phenomena in fruit purees are of particular importance for the food industry and product acceptance by consumers. The aim of this study was to correlate the phase separation with the underlying mechanisms. First, the influence of soluble solids content and temperature on the flow properties of peach puree was determined. Furthermore, considering the fruit puree matrix as a colloidal dispersion, the sedimentation rate, particle size and zeta potential were also determined. The peach puree samples exhibited pseudoplastic behavior, which was effectively described by the power law model. Both the flow consistency coefficient and apparent viscosity increased as the concentration rose. On the contrary, viscosity decreased as temperature increased. In addition, there was no significant effect of temperature on the flow behavior index. Low zeta potential values resulted in sedimentation as expressed by the phase separation index, and the highest sedimentation rate was observed for the sample with the lowest sucrose content.

Effect of Nutrient Management During the Nursery Period on the Growth, Tissue Nutrient Content, and Flowering Characteristics of Hydroponic Strawberry in 2022

The objective of a strawberry nursery is to produce numerous runners and improve the quality of the runner plants, ensuring their uniformity and health. About 80% of the strawberry nurseries in Wanju-gun, Republic of Korea, are cultivated by the growers themselves, which results in variations in the cultivation techniques. Different methods are employed to reduce the nitrogen levels to promote floral bud initiation in the later nursery stage, and these methods vary between farms. This study was conducted on the ‘Sulhyang’ cultivar (Fragaria × ananassa Dutch. cv. Sulhyang) to measure the nutrient content in runner plants obtained from eight growers using various cultivation methods, supply EC levels, nutrient solution termination times, etc., and to correlate the nutrient levels with floral bud initiation during the nursery period. Four investigations were conducted at 15-day intervals from Julian day 214 (2 August) to Julian day 259 (16 September) in 2022, focusing on nutrient management during the nursery period, runner plant growth, petiole nitrate nitrogen content (NO3-N), and soluble solid content (SSC). The NO3-N content decreased, and the SSC/NO3-N ratio increased near the transplanting period, as assessed using a rapid inorganic nutrient diagnostic device. The proportion of runner plants that had advanced to stage 3 or above in floral bud initiation was investigated using a stereomicroscope. As a result, differences in the percentage of floral bud initiation were confirmed based on the varying nutrient management among the farms. In this study, on Julian day 243 (31 August 2022), there was a strong negative correlation (r = −0.86, r2 = 0.73) between the NO3-N content in the runner plants and the percentage of floral bud initiation. These results emphasize the importance of nutrient management during the nursery period, especially for strawberry self-propagating growers, and demonstrate a strong correlation between nutrient content and floral bud initiation in strawberries.

Preharvest Gibberellic Acid Treatment Increases Both Modulus of Elasticity and Resistance in Sweet Cherry Fruit (cv. ‘Bing’ and ‘Lapins’) at Harvest and Postharvest During Storage at 0 °C

Fruit firmness in sweet cherries (Prunus avium L.) is a critical quality parameter highly valued by consumers as it is associated with fruit freshness. In general, firm fruit also cope better with storage and handling. Gibberellic acid (GA) is commonly used by sweet cherry producers to increase firmness, soluble solids content and fruit size. This study evaluated the effects of GA on the rheological properties of sweet cherry fruit at harvest and postharvest storage. Specifically, GA’s influence on susceptibility to mechanical damage during handling was evaluated. The following GA treatments were applied to two sweet cherry cultivars ‘Bing’ and ‘Lapins’: T0, control, T30—GA at 15 ppm applied at pit-hardening and straw-colour stages; T45—GA at 25 ppm at pit-hardening and GA at 20 ppm at straw-colour; and T60—GA at 30 ppm applied at pit-hardening and straw-colour. The results indicate that GA delayed harvest by two to four days in both cultivars, with ‘Lapins’ also showing a significant increase in fruit size. Regardless of spray concentration, GA increased the modulus of elasticity and fruit resistance evaluated as stress at the maximum point at harvest. These effects persisted after 35 days of storage at 0 °C and an additional three days of shelf-life at 15 °C. While the strain or deformation capacity of the fruit at bioyield at harvest was constant across treatments, it was, however, lower in the GA-treated fruit than in the controls during storage at 0 °C under the high-humidity conditions of modified atmosphere packaging. The less mature fruit harvested at colour 3.0 (red/mahogany) were stiffer (reduced deformation) and more sensitive to induced mechanical injury than the fruit harvested later at colour 3.5 (mahogany). The GA treatments increased fruit resistance to damage without increasing tissue deformability. Other questions associated with stiffer tissues and lower deformability during storage at 0 °C under high humidity should be further studied, specifically cultivars that are naturally high in box-cracking sensitivity during storage.

Combining hyperspectral imaging technology and visible-near infrared spectroscopy with a data fusion strategy for the detection of soluble solids content in apples

Soluble solids content (SSC) is an important indicator for evaluating apple quality. This study aimed to assess two spectral techniques (hyperspectral imaging (HSI) and visible-near infrared (Vis-NIR)) combined with low-level and mid-level fusion strategies (LLF and MLF) for the detection of SSC in apples. Firstly, baseline correction (BC), detrending (DT), multiplicative scatter correction (MSC), savitzky-golay (SG), and standard normal variables (SNV) were used for the preprocessing of spectral data. Secondly, genetic algorithm (GA), competitive adaptive reweighted sampling (CARS), and their combinations were used for feature variable extraction. Finally, models were developed using partial least squares regression (PLSR) for spectral data. The results showed that Vis-NIR has an advantage over HSI in predicting apple SSC if only a single spectral technique was considered. The data fusion strategy showed better performance in predicting SSC metrics compared to individual spectral data. Among them, the LLF strategy showed the best performance in predicting SSC, with an Rp2 of 0.927, an RMSEP of 0.529 °Brix, and an Akike information criterion (AIC) of 332.96. In addition, an optimal model based on HSI data was used to achieve visual maps of SSC. It was demonstrated that the fusion of HSI and Vis-NIR data provided a promising method for detecting the SSC in apples.

Impact of postharvest calcium chloride treatments on decay rate and physicochemical quality properties in strawberry fruit

BackgroundPost-harvest losses cause significant product losses in the world, which leads to food waste. Therefore, it is of great importance for people to have access to sufficient amounts of products by increasing the storage period of fruits with applications such as post-harvest calcium chloride (CaCl2). In this study, the effect of calcium chloride (CaCl2) on physical quality parameters and bioactive contents of stored strawberry fruit (Albion cv.) was investigated. Accordingly, strawberries were treated with 2%, 4% and 6% CaCl2 before storage and stored for 15 days (0 ± 0.5 °C and 90 ± 5% RH). Analyses and measurements were conducted every 5 days during the storage period.Weight loss, decay rate, soluble solids content (SSC), acidity, pH, respiration rate, organic acids (malic, citric, ascorbic, fumaric, oxalic, succinic and tartaric) and phenolic compounds (catechin, chlorogenic, ferulic, gallic, o-coumaric, p-coumaric, protocatechuic, quercetin, rutin and syringic) were analyzed as quality parameters during storage.ResultsIn the study, in general, the best values were observed in 6% CaCl2-treated fruits in terms of weight loss, SSC, TA, decay and respiration rates, although they varied according to different storage periods. Similarly, in terms of phenolic compounds, organic acids and vitamin C, 6% CaCl2-treated fruits had significantly better prevention of quality losses. In addition, the most common phenolic compound of strawberry fruits was gallic acid, followed by chlorogenic acid and catechin, respectively. On the other hand, the predominant organic acid observed in the fruits was malic acid, followed by citric acid, succinic acid and oxalic acid, respectively.ConclusionsIn this study, it was observed that CaCl2 applications more effectively prevented weight loss and decay rate by reducing the respiration rate compared to the control group at the end of the storage period (15th day). It was concluded that, particularly, the 6% CaCl2 dose can be used as an important treatment to extend storage life by preserving fruit quality and biochemical changes.

Convolutional neural networks fusing spectral shape features with attentional mechanisms for accurate prediction of soluble solids content in apples

Convolutional neural networks fusing spectral shape features with attentional mechanisms for accurate prediction of soluble solids content in apples