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Peel splitting is a major physiological disorder affecting post-harvest banana quality. This phenomenon occurs only 3-6 days after ripening induction in specific cultivars such as cv. 925 when stored in saturating humidity conditions. In these conditions, Cavendish cultivars (Grande Naine, cv. GN) are not susceptible to splitting. Cvs. 925 and GN were thus investigated to detect possible determinants associated with splitting. Splitting intensity was tentatively found to be associated with an inverse water flux at high relative humidity (RH) through an osmotic peel to pulp water flux resulting from the higher sugar content in the pulp than in the peel. Rheological properties were measured, and although the peel resistance and elasticity in cv. 925 were surprisingly higher than in cv. GN, saturating humidity conditions (100 % RH) substantially reduced the peel resistance. However, the peel epicuticular wax in cv. 925 was clearly thinner than that in cv. GN, thus leading to limitation of peel hydration in cv. GN. Peel splitting in cv. 925 was also associated with a boost in respiration, an increase in oxidative stress markers (HO), resulting in an increase in cellular damage markers (MDA, PEL). Overall, our results suggest that peel splitting at high RH in cv. 925 is related to fast decrease peel water content and the induction of high oxidative stress damage. [ABSTRACT FROM AUTHOR]

Mango fruit ( Mangifera indica L.) is highly perishable and must therefore be quickly stabilized. Drying appears to be one of the most promising stabilization solutions. The traditional mango drying process can be divided into two phases: the first, which is performed at ~80 °C for 10 to 12 h, sees water activity ( a) decline from 0.98 to 0.8. During the second phase, the drying temperature is reduced to 50 °C until a reaches ~0.6. These conditions are highly favorable to enzymatic and non-enzymatic reactions (1st and 2nd step, respectively). The focus of this work was therefore to highlight the effects resulting from the coupling of a and temperature on the development of these classes of reactions during the whole process. Several precursors (reducing sugars and amino acids) and intermediary products of the Maillard reaction were analyzed to estimate non-enzymatic reaction intensity when polyphenoloxidase (PPO) was associated with enzymatic browning. We were able to show that the highest production of 5-hydroxymethyl furfural (5-HMF) as a Maillard reaction marker occurs mainly for an a of 0.6. Kinetic analysis of Maillard reaction precursors and intermediate products in model mango system helped us identify asparagine and arginine as limiting precursors, and 5-HMF as a significant a-dependent product. The impact of the a on the thermal degradation of PPO proved to be radically different. After 8 h at 40 °C, the PPO was almost totally inhibited if this treatment is conducted on a sample at a 0.65, while residual activity was estimated to be 69.4 % for a sample at a 0.98. [ABSTRACT FROM AUTHOR]

Awara (Astrocaryum vulgare M.) pulp oil has been shown to possess anti-inflammatory properties in vivo, and contains an unsaponifiable matter rich in bioactive compounds. This study focused on the ethanolic unsaponifiable fraction (EUF) of awara pulp oil. Its chemical composition has been characterized: carotenoid, phytosterol, and tocopherol contents represent 125.7, 152.6, and 6.8 μg/mg of EUF, respectively. We further evaluated this fraction for anti-inflammatory properties in J774 macrophages activated by lipopolysaccharide (LPS) plus interferon (IFN) γ to understand the biological effects of awara pulp oil. EUF strongly decreased nitric oxide (NO), prostaglandin E(2), tumour necrosis factor (TNF) α, and interleukin (IL) -6 and -10 production in activated J774 cells. Moreover, it inhibited expression of inducible NO synthase and cyclooxygenases-2 in vitro. The anti-inflammatory properties of EUF were also confirmed in vivo by modulation of TNFα, IL-6 and IL-10 serum concentration in an endotoxic shock model. Pre-treatment with awara oil fraction offers promise as a protective means to lower the production of excessive amounts of pro-inflammatory molecules. [ABSTRACT FROM AUTHOR]