Image analysis to quantify the browning in fresh cut tender jackfruit slices

Postharvest melatonin application attenuates browning, delays softening, and maintains the antioxidant potential of jackfruit bulbs

Although the impact of postharvest melatonin (MLT) application in extending the storage life of horticultural produce has been widely studied, its effect in jackfruit remains unknown. This investigation evaluates the influence of MLT dip application (0, 0.05, 0.1, and 0.2 mM) on browning, softening and oxidative stress in cold-stored jackfruit bulbs over a period of 20d. All MLT treatments reduced browning index and oxidative stress, while activities of browning-related enzymes were comparatively lower in the 0.1 mM MLT treatment. Treatment with 0.2 mM MLT maintained elevated levels of antioxidants as compared to control. Higher bulb firmness, total pectin and cellulose content with considerably lower activities of cell wall degrading enzymes were observed in all MLT treatments. In conclusion, MLT (0.1 and 0.2 mM) is an effective treatment for mitigating postharvest browning and oxidative stress in addition to delaying fruit softening and maintaining the antioxidant potential of cold-stored jackfruit bulbs.

The Influence of Surface Treatment on the Color of Enamel and Dentin: An In Vitro Study Using Machine Learning-Based Analysis

OBJECTIVE

To investigate how surface treatment affects the color of enamel and dentin, and to evaluate whether the color differences are acceptable.

MATERIALS AND METHODS

Freshly extracted premolars were prepared using diamond burs (blue, red, and yellow tapes). Tooth surfaces were divided into control and acid-etched areas and treated with phosphoric acid (5, 15, 30, 45, and 60 s). Adhesives were applied and light-cured. Hyperspectral images were captured to analyze reflectance spectra, calculating L, a, b, and ΔE2000 values under the D65 illuminant. Enamel and dentin slices underwent atomic force microscopy for surface roughness. A random forest model was trained to assess the effects of multiple factors on color differences. Statistical analyses included one-way ANOVA, Tukey tests, and independent-sample t-test.

RESULTS

Extended acid-etching times notably increased ΔE2000 values for enamel, surpassing acceptable thresholds in all groups except for the 5-s acid-etching followed by adhesive application. Dentin ΔE2000 remained stable regardless of surface treatment. Machine learning highlighted the influence of acid etching and surface roughness on enamel. Bur tape color had minimal impact.

CONCLUSIONS

The effects of acid etching on the color vary between enamel and dentin. Greater attention should be focused on enamel surface. Acid-etching time should be appropriately reduced.

CLINICAL SIGNIFICANCE

Comprehending the varying impacts of surface treatment on the color of enamel and dentin could contribute to achieving superior esthetic outcomes.

Developments and opportunities in minimal processing and production of tender jackfruit flour

Tender jackfruit is quite popular for culinary preparations. Technologies and value-added products of matured and ripened jackfruit are in the commercial domain, but there is a high demand to work on the processing and value addition of tender jackfruit. Especially, interventions are required for the mechanization of different post-harvest operations and to develop process protocols. Minimal processing of tender jackfruit has immense commercial potential as it can make handling easy and reduce transportation costs. Controlling the browning of cut tender jackfruit is a challenge and requires research interventions to develop a safe process protocol minimizing or avoiding the use of chemicals. Tender jackfruit powder, also called flour, is a novel product being invented to explore its possible applications in different food products. However, scientific interventions are required to develop a process protocol for tender jackfruit powder production along with the development of machines for operations like shredding and grinding. Conventional grinding operations lead to nutritional loss of jackfruit powder; hence, there is a great opportunity to develop a low-temperature grinding system for the production of quality powder. The available literature, particularly on tender jackfruit processing, has been summarized in the present paper with its critical analysis and future prospects.

Graphical abstract

Bioturbation effect of artificial inoculation on the flavor metabolites and bacterial communities in the Chinese Mao-tofu fermentation

A comparison between artificially inoculated Mao-tofu (CC) and naturally fermented Mao-tofu (MM) indicated that artificially adding Mucor plasmaticus to Mao-tofu dramatically enhanced the essential amino acid (EAA) content, as well as umami and sweet amino acids. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis revealed that phenol (3.226 μg/g), 1-octen-3-ol (5.031 μg/g), ethyl heptanoate (1.646 μg/g), and indole (3.422 μg/g) were the key flavor components in Mao-tofu. Unlike MM, CC displayed a substantial increase in esters and a considerable decrease in foul odor substances, including sulfur-containing compounds and indole. Lactococcus raffinolactis, Enterobacter sp. 638, and Streptococcus parauberis KCTC 11537 represented the key bacterial species altering the amino acids and flavor of Mao-tofu according to PacBio single-molecule real-time (SMRT) sequencing and correlation analysis. This study presents the technical feasibility of artificially inoculating Mao-tofu to regulate the core bacterial communities and control the quality of fermented soybean products.

Nisin and ε-polylysine combined treatment enhances quality of fresh-cut jackfruit at refrigerated storage

This study investigated the effects of nisin combined with ε-polylysine on microorganisms and the refrigerated quality of fresh-cut jackfruit. After being treated with distilled water (control), nisin (0.5 g/L), ε-polylysine (0.5 g/L), and the combination of nisin (0.1 g/L) and ε-polylysine (0.4 g/L), microporous modified atmosphere packaging (MMAP) was carried out and stored at 10 ± 1°C for 8 days. The microorganisms and physicochemical indexes were measured every 2 days during storage. The results indicated that combined treatment (0.1 g/L nisin, 0.4 g/L ε-polylysine) had the best preservation on fresh-cut jackfruit. Compared with the control, combined treatment inhibited microbial growth (total bacterial count, mold and yeast), reduced the weight loss rate, respiratory intensity, polyphenol oxidase and peroxidase activities, and maintained higher sugar acid content, firmness, and color. Furthermore, it preserved higher levels of antioxidant compounds, reduced the accumulation of malondialdehyde and hydrogen peroxide, thereby reducing oxidative damage and maintaining high nutritional and sensory qualities. As a safe application of natural preservatives, nisin combined with ε-polylysine treatment has great application potential in the fresh-cut jackfruit industry.

Image analysis-based discoloration rate quantification and kinetic modeling for shelf-life prediction in herb-coated pear slices

The present research study aimed to examine three different herb extract's effects on the discoloration rate of fresh-cut pear slices using an image analysis technique. Pear slices were sprayed and dip-coated with Ocimum basilicum, Origanum vulgare, and Camellia sinensis (0.1 g/ml) extract solution. During 15 days storage period with three days intervals, all sprayed/dip-coated pear slices were analyzed for the quality attribute (TA) and color parameters notably a*, b*, hue angle (H*), lightness (L*), and total color change (ΔE). Further, order kinetic models were used to observe the color changes and to predict the shelf-life. The results obtained showed that the applicability of image analysis helped to predict the discoloration rate, and it was better fitted to the first-order (FO) kinetic model (R2 ranging from 0.87 to 0.99). Based on the kinetic model, color features ΔE and L* was used to predict the shelf-life as they had high regression coefficient values. Thus, the findings obtained from the kinetic study demonstrated Camellia sinensis (assamica) extract spray-coated pear slices reported approximately 28.63- and 27.95-days shelf-stability without much discoloration compared with all other types of surface coating.

The influences of acidic electrolyzed water on quality and bacteria community of fresh-cut jackfruit in storage

This study evaluated the effects of acidic electrolyzed oxidizing water (AEW) on the quality and bacterial communities of fresh-cut jackfruit during storage. The result showed that AEW treatment, as compared to the CK group (without AEW treatment), could effectively inhibit the browning, maintain higher firmness and higher amounts of total titratable acidity (TTA) (0.21%), sugars (58.30 g/kg), ascorbic acids (28.72 mg/kg) and total phenolics (35.47 mg/kg) of fresh-cut jackfruits, and suppress the decrease of antioxidant ability during 4–8 days of storage. Additionally, the bacterial communities were significantly affected by AEW during storage. In particular, the AEW treated samples showed lower abundance of Pseudomonas and Lactobacillus than the CK group after storage of 8 day. And energy metabolism, nucleotide metabolism has the significantly lower (p < 0.05) relative abundance in the AEW group than in CK group. These results suggested that AEW (pH: 4.2–4.5, ACC: 35–38 mg/L) treatment could maintain the quality of fresh-cut jackfruit during storage. It could be attributed to that AEW treatment affect the growth and metabolism of bacterial communities, resulting in the decrease of nutrients consumption.

Insights into phytonutrient profile and postharvest quality management of jackfruit: A review

Jackfruit (Artocarpus heterophyllus Lam.), also known as 'vegetarian's meat', is an excellent source of carbohydrates, protein, fiber, vitamins, minerals, and several phytochemicals. It is a climacteric fruit that exhibits an increase in ethylene biosynthesis and respiration rate during fruit ripening. The market value of jackfruit is reduced due to the deterioration of fruit quality during storage and transportation. There is a lack of standardized harvest maturity index in jackfruit, where consequently, fruit harvested at immature or overmature stages result in poor quality ripe fruit with short storage life. Other factors responsible for its short postharvest life relate to its highly perishable nature, chilling sensitivity and susceptibility to fruit rot which result in significant qualitative and quantitative losses. Various postharvest management techniques have been adopted to extend the storage life, including cold storage, controlled atmosphere storage, modified atmosphere packaging, edible coatings, chemical treatment, and non-chemical alternatives. Diversified products have been prepared from jackfruit to mitigate such losses. This comprehensive review highlights the nutritional profile, fruit ripening physiology, pre and postharvest quality management, and value addition of jackfruit as well as the way forward to reduce postharvest losses in the supply chain.

Nontarget Metabolites of Rhizomes of Edible Sacred Lotus Provide New Insights into Rhizome Browning

The “edible rhizome” variant of Nelumbo nucifera with various cultivars has a long history of use as a food in East Asia. In this study, 48 target metabolites were untargeted and identified in 212 rhizome cultivars (tropical and temperate types) using ultraperformance liquid chromatography-electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry; among these, 32 compounds were newly reported in the rhizome. Combined with the browning phenotype of 212 lotus rhizomes, (epi) catechin, norarmepavine, and N-feruloyl-3-methoxytyramine were used as predominant chemical markers to separate different degrees of lotus rhizome browning. p-Coumaroyltyramine and N-trans-feruloyltyramine were selected as predominant chemical markers to investigate the differential expression between tropical and temperate lotus using principal component analysis and orthogonal partial least squares discriminant analysis. Shared and unique structure plots were used to compare the outcomes of the ecotype and browning OPLS model, showing that variation in tropical lotus rhizome browning is not obvious; this will be of great importance for genetic improvement by providing a hereditary basis.

Identification of different bran-fried Atractylodis Rhizoma and prediction of atractylodin content based on multivariate data mining combined with intelligent color recognition and near-infrared spectroscopy

Unclear established standard of bran-fried Atractylodis Rhizoma (BFAR), a commonly used drug in Traditional Chinese Medicine (TCM), compromised its clinical efficacy. In this study, we explored the correlation between color and near-infrared spectroscopy (NIR) feature with content of atractylodin, then established a rapid recognition model for the optimal degree of processing for BFAR preparation. The results of the Pearson analysis indicated that the color values were significantly and positively correlated with atractylodin content. The back propagation artificial neural network algorithm and cluster analysis revealed the color of different BFAR could be accurately divided into three categories; subsequently, the color range for the optimal degrees of stir-frying was established as follows: R[red value (105.79-127.25)], G[green value(75.84-89.64)], B[blue value(33.33-42.73)], L[Lightness (81.26-95.09)].Using NIR, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and cluster analysis, three types of BFAR were accurately identified. The prediction model of atractylodin content was established using partial least squares regression analysis. The R² of the validation set was 0.9717 and the root mean square error was 0.026. In the color judgment model, the processing degree of 8 batches of BFAR from the market is inferior. According to the NIR judgment model, the processing degree of all samples from the market is inferior. In conclusion, the best fire degree of BFAR can be identified quickly and accurately based on our established model. It is a potential method for quality evaluation of Chinese Materia Medica processing.

Influence of Domestic Cooking on Quality, Nutrients and Bioactive Substances of Undaria pinnatifida

Undaria pinnatifida (UP) is a brown algae commonly consumed as food in Asian countries. The purpose of this study was to compare the effects of different domestic cooking methods (i.e., air frying (AF), microwaving, and high temperature and pressure (HTP) cooking) on the nutritional and bioactive substances in UP, as well as on UP color and texture, in order to identify methods to retain beneficial components better. In this study, microwave treatment resulted in better retention of color, polysaccharide (4.17 ± 0.07 mg glucose equivalents (GE)/g dry weight (dw) ), total phenol content (TPC) (1.50 ± 0.0062 mg gallic acid equivalents (GAE)/g dw) as well as chlorophyll a (18.18 ± 0.41 mg/g fresh weight (fw) ) and fucoxanthin (281.78 ± 17.06 μg/g dw). HTP treatment increased the TPC of UP (1.69 ± 0.0075 mg GAE/g dw), and AF treatment resulted in a lower loss of total amino acids (2.14 ± 0.15%). Overall, microwave cooking appeared to be the best among the three in producing cooked UP with high quality. This study provided a useful guideline in selection of cooking for UP which could retain more health-beneficial substances and yield products with better eating qualities to improve human diet.

Effect of sorbitan monopalmitate on the polymorphic transitions and physicochemical properties of mango butter

The present study reports the effect of sorbitan monopalmitate (SM) as a crystallization modifier on the physicochemical properties of mango butter (MB). The concentration of SM was varied in the range of 1 and 5 wt%. The addition of SM promoted the aggregation of globular MB crystals. The FTIR patterns did not show any significant changes when SM was added. XRD and DSC analyses confirmed the crystallization of MB crystals in stable β' and β (V) polymorphic states. However, SM also introduced imperfections in the crystal lattices of MB. Among all formulations, M2 (SM; 1% w/w) possessed a mechanically stable network structure. The crystallization rate of MB was tailored by SM in a concentration-dependent manner. The solid content was highest in M4 (SM; 5% w/w) at 10 °C and 30 °C among all the oleogels. In gist, SM in manageable quantities can be utilized for preparing custom-tailored MB-based products.

Reacciones químicas de los azúcares simples empleados en la industria alimentaria

Hoy en día, la demanda de los consumidores por productos saludables conlleva a la industria alimentaria a realizar investigaciones sobre las diferentes reacciones químicas de diversos macronutrientes como azúcares, polisacáridos, proteínas y lípidos con el fin de comprender su interacción con otros componentes presentes en las matrices alimentarias, encontrar estrategias para reducir la aparición de compuestos tóxicos, garantizar la seguridad alimentaria en los alimentos procesados térmicamente y formular nuevos productos con características de mayor valor. El presente artículo expone las reacciones químicas que presentan los carbohidratos simples, considerando los mecanismos químicos involucrados, el tipo de compuestos generados, la importancia de estos compuestos en la industria de alimentos y algunos efectos, tanto favorables como desfavorables, de dichas reacciones.

Quality Control of Fresh-Cut Apples after Coating Application

The growing demand for ready-to-eat fresh fruits has led to set-up appropriate strategies for preserving fruit quality and freshness of such commodities. To slow down the deterioration events such as respiration, moisture loss and enzymatic activity, ready-to-eat products should be protected with an edible film. A suitable coating should combine hydrophilic and hydrophobic features to ensure good mechanical and gas barrier properties. Alginate/essential oil nanoformulations, one with low and the other with high oil content, here proposed to protect apple pieces during storage, were first characterized through dynamic light scattering and rheology. The effect of the application of the nanoformulations on the quality parameters of apples stored at 4 °C was considered by evaluating weight loss, pH and titratable acidity, total phenols content and the fruit appearance during storage. Mainly on the basis of pH and titratable acididty variation, the nanoformulation with low oil content resulted eligible for preserving the quality of fresh-cut apple pieces during storage.