Search Results (6)

The natural abundance, polymer stability, biodegradability, and natural antimicrobial properties of lignin open a wide range of potential applications aiming for sustainability. In this work, the effects of 1% (w/w) softwood kraft lignin nanoparticles (SLNPs) on the physicochemical properties of polybutylene succinate (PBS) composite films were investigated. Incorporation of SLNPs into neat PBS enhanced T_d from 354.1 °C to 364.7 °C, determined through TGA, whereas T_g increased from −39.1 °C to −35.7 °C while no significant change was observed in T_m and crystallinity, analyzed through DSC. The tensile strength of neat PBS increased, to 35.6 MPa, when SLNPs were added to it. Oxygen and water vapor permeabilities of PBS with SLNPs decreased equating to enhanced barrier properties. The good interactions among SLNPs, thymol, and PBS matrix, and the high homogeneity of the resultant PBS composite films, were determined through FTIR and FE-SEM analyses. This work revealed that, among the PBS composite films tested, PBS + 1% SLNPs + 10% thymol showed the strongest microbial growth inhibition against Colletotrichum gloeosporioides and Lasiodiplodia theobromae, both in vitro, through a diffusion method assay, and in actual testing on active packaging of mango fruit (cultivar “Nam Dok Mai Si Thong”). SLNPs could be an attractive replacement for synthetic substances for enhancing polymer properties without compromising the biodegradability of the resultant material, and for providing antimicrobial functions for active packaging applications. Full article

Mango (Mangifera indica L.) ‘Nam Dok Mai Si Thong’ is an important cultivar for export from Thailand. Export mainly takes place via air transport, but for about 2 h at the loading area (tarmac), unit loading devices (ULDs) are exposed to ambient environmental conditions. In this research, the effects of different temperature conditions at the loading area (tarmac) and the distance of the production area from the tarmac on the quality of fresh mango fruits were studied. The treatments included three temperature conditions for 2 h (simulated handling in tarmac)—constant temperature (20 °C), non-insulated or insulated and exposed to sun—and two distances of the tarmac from the production area—short distance (i.e., transport occurring 53 h after harvest) and long distance (i.e., transport occurring 70 h after harvest). The temperature variation in the boxes exposed to the sun was greater in the non-insulated than in the insulated boxes, but this effect was more pronounced in fruit from the short-distance production area (28.1 °C insulated and 36.9 °C non-insulated) than in fruit from the long-distance production area (34.2 °C insulated and 38 °C non-insulated). Insulation and short distance increased the shelf life, decreased weight loss, delayed the decrease in average firmness and rupture force, etc. The insulation of mango fruit boxes mitigates the deleterious effect of exposure to 2 h of direct sun by reducing the increase in temperature, thus improving the shelf life and quality of mango fruit. Full article

Mango ‘Nam dok mai si thong’ is in high demand worldwide, displaying desirable attributes which include a particularly sweet flavour and visually appealing appearance. Physiological and biochemical changes that occur in the fruit post-harvest are key factors in determining fruit quality and, consequently, predicted shelf life. In order to understand which post-harvest markers play crucial roles during the ripening process, as well as those which are a consequence of disease infection and physical damage caused by essential oil vapour, partial least squares (PLS) correlation models were used. During storage, physiochemical (percent weight loss, peel colour, firmness, pH, and peel electrolyte leakage) and biochemical (titratable acidity, total soluble solids, total phenolic compounds, total flavonoid compounds, antioxidants, total sugar, and reducing sugar content) parameters, as well as near-infrared (NIR) spectra, were monitored and correlated with visual post-harvest physiological responses. The majority of analysed markers displayed distinct relationships with the ripening process of mangoes, where for non-destructive parameters (R² = 0.86), lightness (L*) and b* value were notably significant, and for destructive parameters (R² = 0.79), pH and total soluble solids were notably significant. Similarly, the same markers were also correlated with physical damage and post-harvest mango disease infection severity, possibly through polysaccharide deformation and activation of browning-related enzymes. NIR imaging results also revealed the absorbent regions involved in biochemical alterations (water and enzymes; absorbance at 1170 nm, 1400–1500 nm, and 2150–2250 nm) that pertain to the fruit’s quality. The findings from this work provide an initial step towards the development and assessment of quality measures for ‘Nam dok mai si thong’ mango. Full article

Day-to-day advancements in food science and technology have increased. Indicators, especially biopolymer-incorporated organic dye indicators, are useful for monitoring the ripeness quality of agricultural fruit products. In this investigation, methylcellulose films—containing pH dye-based indicators that change color depending on the carbon dioxide (CO₂) levels—were prepared. The level of CO₂ on the inside of the packaging container indicated the ripeness of the fruit. Changes in the CO₂ level, caused by the ripeness metabolite during storage, altered the pH. The methylcellulose-based film contained pH-sensitive dyes (bromothymol blue and methyl red), which responded (through visible color change) to CO₂ levels produced by ripeness metabolites formed during respiration. The indicator solution and indicator label were monitored for their response to CO₂. In addition, a kinetic approach was used to correlate the response of the indicator label to the changes in mango ripeness. Color changes (the total color difference of a mixed pH dye-based indicator), correlated well with the CO₂ levels in mango fruit. In the ‘Nam Dok Mai Si Thong’ mango fruit model, the indicator response correlated with respiration patterns in real-time monitoring of ripeness at various constant temperatures. Based on the storage test, the indicator labels exhibited color changes from blue, through light bright green, to yellow, when exposed to CO₂ during storage time, confirming the minimal, half-ripe, and fully-ripe levels of mango fruit, respectively. The firmness and titratable acidity (TA) of the fruit decreased from 44.54 to 2.01 N, and 2.84 to 0.21%, respectively, whereas the soluble solid contents (SSC) increased from 10.70 to 18.26% when the fruit ripened. Overall, we believe that the application of prepared methylcellulose-based CO₂ indicator film can be helpful in monitoring the ripeness stage, or quality of, mango and other fruits, with the naked eye, in the food packaging system. Full article

Mango fruits have a high nutritional value and are beneficial to health. However, losses frequently occur after harvest, because they are perishable. Salicylic acid (SA) can be used to preserve fruit quality and maintain their nutritional contents. Therefore, this study was conducted to investigate the effects of applications of 2 mM SA on the physicochemical properties, bioactive compounds, and antioxidant and anti-inflammatory activities of mango fruit. For this purpose, mango fruits received preharvest (Pre SA) or postharvest applications of SA (Post SA), or their combination (Pre + Post SA); the fruits were stored at 13 °C for 20 days. Weight loss, decay, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity were maintained in SA-treated fruit. The Pre + Post SA treatment was superior in delaying fruit ripening, and maintaining lower soluble solids contents and higher total acidity. In addition, total phenolic compounds, ferric reducing antioxidant power, and free radical scavenging activity of anti-inflammatory substances (such as nitric oxide), as well as hyaluronidase inhibition, were higher in the Pre + Post SA treatment throughout storage. Therefore, both pre- and postharvest SA treatments are recommended for preserving the quality of mango fruit, such as Nam Dok Mai Si Thong, and for maintaining their nutritional properties for human health. Full article

A metabolomics-flavoromics approach was conducted to assess the micromolecules of ‘Nam Dok Mai Si Thong’ and ‘Nam Dok Mai No. 4’ mango cultivars from two seasons. During ripening, FAMEs, FFAs, fatty alcohols, sterols, and organic acids were dominant at 0–2 days, whereas amino acids, sugars, and volatile organic compounds, including esters, alcohols, ketones, aldehydes, and terpenes, were at higher levels at 4–8 days. Nine metabolites (palmitic/linoleic/linolenic/citric/malic acids, β-sitosterol, sucrose, glycine, and leucine) and two volatile organic compounds (ethyl octanoate/decanoate) were related to ripening-associated changes within eight days. During ripening, sucrose at 6–8 days, citric/malic acid at 0–2 days, glycine and leucine at 4 days, and ethyl octanoate and ethyl decanoate at 8 days could be used as quality biomarkers for Nam Dok Mai Si Thong; palmitic/linoleic/linolenic acids at 0 days and β-sitosterol at 0–4 days could be used as quality biomarkers for Nam Dok Mai No. 4. Full article