Prediction of textural attributes using color values of banana (Musa sapientum) during ripening

Alginate-Based Emulsions and Hydrogels for Extending the Shelf Life of Banana Fruit

Edible coatings are used to extend the shelf life of various fruit, including bananas (Musa from the Musaceae family). After harvest, bananas reach the ripening and subsequent senescence phase. During senescence, the quality of the fruit deteriorates as it takes on a brown color and the tissue becomes soft. To extend the shelf life of such a fruit, effective methods to delay ripening are required. In this study, an alginate-based emulsion, i.e., an oil-in-water emulsion of lemongrass essential oil in alginate, was used to combine the mechanical properties of hydrocolloids with the water barrier properties of the oil phase. The emulsion was sprayed onto the whole fruit with an airbrush, and calcium chloride was added to promote gelling of the alginate. Compared to the uncoated fruit, coated bananas remained uniform in appearance (peel color) for longer, showed less weight loss, had a delay in the formation of total soluble solids, and in the consumption of organic acids. The shelf life of the coated fruit was extended by up to 11 days, at least 5 days more than uncoated bananas. Overall, the proposed coating could be suitable for reducing the global amount of food waste.

Postharvest melatonin and chitosan treatments retain quality of 'Williams' bananas during ripening

The effect of postharvest dipping treatments with 0.5 mM melatonin (MT) and 1% chitosan (CT) either alone or in combination on quality of pre-climacteric 'Williams' bananas during ripening at ambient conditions were investigated. MT or CT treatments delayed ripening by retaining greener peel, higher firmness, titratable acidity (TA), but lower total soluble solids (TSS) and TSS/TA, weight loss, browning and electrolyte leakage than the control. Total phenol (TPC) and flavonoid contents (TFC) in both peel and pulp increased up to 6 days and then decreased and was higher in treated fruit than the control. Vitamin C content decreased up to 3 days, then increased and was higher in treated fruit than control. MT and CT combination exhibited the highest TPC, TFC and vitamin C contents compared to other treatments. Radical scavenging capacity (RSC) of peel and pulp increased up to 6 days, then decreased and was higher in treated fruit than the control. The treated fruit exhibited lower polyphenoloxidase (PPO) and hydrolytic enzymes but higher peroxidase (POD) activities in both peel and pulp than the control. Postharvest treatments with 0.5 mM MT and 1% CT alone or in combination could be used to retain quality of 'Williams' bananas during ripening.

Prediction of banana maturity based on the sweetness and color values of different segments during ripening

To predict the maturity of bananas, the present study used non-destructive methods to analyze changes in the sweetness and color of the stalks, middles, and tips of bananas during ripening. The results indicated that the respective maturation of these three segments did not occur simultaneously, as indicated by the differential enzyme activity and gene expression levels recorded in these segments. A principal component analysis and cluster plots were used to review the classification of banana maturity, highlighting that banana maturation can be divided into six stages. Two distinct maturity prediction algorithms were established using random forest, artificial neural network, and support vector machines, and they also indicated that dividing the maturity of bananas into six stages was adequate. These findings contribute to the development of quality evaluation and of a rapid grading system for processing, which improves the quality and sale of banana fruits and the related processed products.

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Sweetness and color during ripening were assessed along banana fingers.

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A new maturity prediction model was established for bananas.

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Banana maturity was divided in six stages.

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The theoretical basis for developing a maturity grading detection device was set.

Combined effects of tangerine oil vapour mixed with banana flavour to enhance the quality and flavour of 'Hom Thong' bananas and evaluating consumer acceptance and responses using electroencephalography (EEG)

The objectives of this study were to investigate the effect of tangerine oil (TO) at 25, 50 and 75 µL mixed with banana flavour (BF) at 25, 50 and 75 µL to protect the quality and enhance the flavour of bananas. Then, 25 µL TO + BF 50 µL were selected for studying the quality of bananas stored at 13 °C ±   2 °C for 7 days, and was used to test consumer brain responses using an electroencephalography (EEG). Results showed that mould grew and decomposition occurred in 10 and 50% of the 25 µL TO + 50 µL BF mixture and control, respectively, after 7 days. Furthermore, this ratio increased ripening by having higher L*, b*, firmness and total soluble solid than the control (p < 0.05), whereas titratable acidity and pH were maintained (p > 0.05). The EEG demonstrated that consumption of TO-treated banana could increase brain alertness using stimulating the beta wave activity on banana stimulations for human brain. Limonene, one of the main components of TO, was found in the flesh of treated banana after storage for 4 weeks and possibly interacted with other components to improve antifungal activity and brain response.

Non-invasive, real time in-situ techniques to determine the ripening stage of banana

Bananas were examined starting from ripening stage R2 (green) to stage R7 (overripe), to identify suitable non-invasive, real time in-situ technologies to separate the ripening stages: (1) Chlorophyll degradation, measured by the DA meter, decreased from ca. 2.1 (R2) to 0.2 IAD units (R7), i.e. tenfold decline. (2) Colour CIE-Lab a values dramatically increased as indication of chlorophyll breakdown and enable differentiation between all ripening stages R2 to R7. Colour angles declined from 98.7° hue (R2), 97.3° hue (R3), 92.7° hue (R4), 89.4° hue (R5); 87.5° hue (R6) until 82.0° hue (R7). (3) Spectroscopy showed two light reflectance troughs at 494 nm and 679 nm. A novel banana ripening index (BRI) was developed and is proposed to identify and distinguish the ripening stages of banana with values starting at 4 at R1 and peaking at 8.1 at ripening stage R7. (4) Peel gloss increased from stage R2 (150 a.u.) to stage R7 (220 a.u.) in the order of ca. 50% followed by a subsequent decrease thereafter. (5) Peel softening declined as fruit firmness dropped from 82 Shore at stage R2 to 42 Shore at stage R7 (overripe), measured also at the centre of the banana fruit. (6) After a constant 90.5% water content per fresh mass (FM) in the banana peel until stage R5, the subsequent drop to 82.9% FM at R7 and 7.6% water translocation viz displacement from the peel to pulp explained this softening. All the above results identified the fruit centre (rather than the tip) as a suitable candidate due to the most advanced ripening and least curved surface region of the fruit with easy access, when a carton is opened and the hands become accessible. This novel approach based on a comparison has shown the DA-meter, colorimeter and spectrometer as suitable candidates for the identification of each ripening stage. The combination of these three devices may be suitable for monitoring of banana ripening rooms in terms of temperature and humidity in addition to the present, colour-based ripening scale.

Characteristics of banana B genome MADS-box family demonstrate their roles in fruit development, ripening, and stress

MADS-box genes are critical regulators of growth and development in flowering plants. Sequencing of the Musa balbisiana (B) genome has provided a platform for the systematic analysis of the MADS-box gene family in the important banana ancestor Musa balbisiana. Seventy-seven MADS-box genes, including 18 type I and 59 type II, were strictly identified from the banana (Pisang Klutuk Wulung, PKW, 2n = 2x = 22) B genome. These genes have been preferentially placed on the banana B genome. Evolutionary analysis suggested that M. balbisiana MCM1-AGAMOUS-DEFICIENS-SRF (MbMADS) might be organized into the MIKC^c, MIKC*, Mα, Mβ, and Mγ groups according to the phylogeny. MIKC^c was then further categorized into 10 subfamilies according to conserved motif and gene structure analyses. The well-defined MADS-box genes highlight gene birth and death in banana. MbMADSes originated from the same ancestor as MaMADSes. Transcriptome analysis in cultivated banana (ABB) revealed that MbMADSes were conserved and differentially expressed in several organs, in various fruit developing and ripening stages, and in stress treatments, indicating the participation of these genes in fruit development, ripening, and stress responses. Of note, SEP/AGL2 and AG, as well as other several type II MADS-box genes, including the STMADS11 and TM3/SOC1 subfamilies, indicated elevated expression throughout banana fruit development, ripening, and stress treatments, indicating their new parts in controlling fruit development and ripening. According to the co-expression network analysis, MbMADS75 interacted with bZIP and seven other transcription factors to perform its function. This systematic analysis reveals fruit development, ripening, and stress candidate MbMADSes genes for additional functional studies in plants, improving our understanding of the transcriptional regulation of MbMADSes genes and providing a base for genetic modification of MADS-mediated fruit development, ripening, and stress.

Non-invasive determination of surface features of banana during ripening

Ripening of dessert banana (Musa sap.) is associated with changes in colour (green to yellow starting from the cente), softening, and surface features. These have mostly been investigated using distinct technologies. Hence, here changes in surface features were examined with two novel, non-invasive techniques: a luster sensor and a 3D profilometer. The profiler measures the 3D surface characteristics of an area, rather than a single profile line, and corrects data for curvature of the fruit. The luster sensor detected an increase in glossiness from stage 3 (green) to stage F7a (ripe) of ca. 35%, followed by a decrease in glossiness from stage F7a to F7b (overripe). The profilometer provided visual and parametric roughness values (Ra) for ripening. Cavendish bananas showed an increase from 2.5 to 6.6 µm during ripening stage 3 (green) to stage 7b (overripe). Another roughness value, Rz, increased concomitantly from 13.1 µm at stage 3 (green) to 26.9 µm at stage F7b (overripe). The study showed that the centre of the fruit was the best region for surface imaging, because it was the most advanced ripening part of the banana fruit, easily curved, and the region of the fruit can be accessed when a carton was opened. This study shows that it is now possible to monitor the changes in surface glossiness and roughness during the ripening of Cavendish bananas using two novel non-invasive technologies. The compact luster sensor may become a component of a portable probe and manual control of packing units. Differences in the predicted green life can be used to prioritize containers for unloading in the discharge port or to implement quality-based warehouse management strategies. Containers that arrive at banana ripening rooms before their green life ends, can be re-routed, in addition to the present, colour-based ripening scale.

Implications of the Red Beet Ripening on the Colour and Betalain Composition Relationships

The evolution during ripening of Beta vulgaris (var. Pablo) on colour and betalain composition, not previously conducted in conjunction in red beets, has been examined. According to the results, it could be asserted that the ripening stage significantly (p < 0.05) influenced on all the studied parameters. On the basis of the betalain content, the optimum ripening stage corresponded to a medium weigh-to-calibre ratio, in the light of the significantly (p < 0.05) higher content of betalains, especially betanin and vulgaxanthin I. Moreover, colour attributes also differed during ripening, having the medium-ripened beetroots a significantly (p < 0.05) more reddish hue (h_ab) and lower lightness (L*), probably due to the higher content of betaxanthins in this stage. The colour differences among red beets in the stage II and the rest of stages were visually appreciable (ΔE*_ab > 3) and mainly qualitative. A new range of opportunities for diversification of colorant market, from a nutritional and colorimetric point of view, could be possible by employing red beets with different stages of ripening.

Development of Metal-Organic Framework for Gaseous Plant Hormone Encapsulation To Manage Ripening of Climacteric Produce

Controlled ripening of climacteric fruits, such as bananas and avocados, is a critical step to provide consumers with high-quality products while reducing postharvest losses. Prior to ripening, these fruits can be stored for an extended period of time but are usually not suitable for consumption. However, once ripening is initiated, they undergo irreversible changes that lead to rapid quality loss and decay if not consumed within a short window of time. Therefore, technologies to slow the ripening process after its onset or to stimulate ripening immediately before consumption are in high demand. In this study, we developed a solid porous metal-organic framework (MOF) to encapsulate gaseous ethylene for subsequent release. We evaluated the feasibility of this technology for on-demand stimulated ripening of bananas and avocados. Copper terephthalate (CuTPA) MOF was synthesized via a solvothermal method and loaded with ethylene gas. Its crystalline structure and chemical composition were characterized by X-ray diffraction crystallography, porosity by N2 and ethylene isotherms, and morphology by electron microscopy. The MOF loaded with ethylene (MOF-ethylene) was placed inside sealed containers with preclimacteric bananas and avocados and stored at 16 °C. The headspace gas composition and fruit color and texture were monitored periodically. Results showed that this CuTPA MOF is highly porous, with a total pore volume of 0.39 cm(3)/g. A 50 mg portion of MOF-ethylene can absorb and release up to 654 μL/L of ethylene in a 4 L container. MOF-ethylene significantly accelerated the ripening-related color and firmness changes of treated bananas and avocados. This result suggests that MOF-ethylene technology could be used for postharvest application to stimulate ripening just before the point of consumption.

Prediction of banana quality indices from color features using support vector regression

Banana undergoes significant quality indices and color transformations during shelf-life process, which in turn affect important chemical and physical characteristics for the organoleptic quality of banana. A computer vision system was implemented in order to evaluate color of banana in RGB, L*a*b* and HSV color spaces, and changes in color features of banana during shelf-life were employed for the quantitative prediction of quality indices. The radial basis function (RBF) was applied as the kernel function of support vector regression (SVR) and the color features, in different color spaces, were selected as the inputs of the model, being determined total soluble solids, pH, titratable acidity and firmness as the output. Experimental results provided an improvement in predictive accuracy as compared with those obtained by using artificial neural network (ANN).