Banana, papaya and pineapple are the most consumed tropical fruits in the world, being Brazil one of the main producers. Fungi Colletotrichum musae, Colletotrichum gloeosporioides and Fusarium subglutinans f.sp. ananas cause severe post harvest diseases and losses in fruits quality. The aim of this work was to evaluate the effectiveness of five monoterpenes to inhibit the mycelial growth and conidia germination of these three phytopathogens. The monoterpenes citral, citronellal, L-carvone, isopullegol and α-pinene were diluted in ethanol to final concentrations from 0.2 to 1%. All monoterpenes were found to inhibit the growth of the three studies fungi in a dose-dependent manner. Citral was the most effective of the oils tested and showed potent fungicidal activity at concentrations above 0.5%. Also, in vivo evaluation with these tropical fruits demonstrated the efficiency of citral to inhibit fungal growth. These results indicate the potential use of citral as a natural pesticide control of post-harvest fruit diseases.

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Coconut palm (Cocos nucifera) is an important commercial crop in many tropical countries, but its industry generates large amounts of residue. One way to address this problem is to use this residue, coconut husk, to produce second-generation (2G) ethanol. The aim of this review is to describe the methods that have been used to produce bioethanol from coconut husk and to suggest ways to improve different steps of the process. The analysis performed in this review determined that alkaline pretreatment is the best choice for its delignification potential. It was also observed that although most reported studies use enzymes to perform hydrolysis, acid hydrolysis is a good alternative. Finally, ethanol production using different microorganisms and fermentation strategies is discussed and the possibility of obtaining other added-value products from coconut husk components by using a biorefinery scheme is addressed.

Cocos nucifera L., coconut, is a palm of high importance in the food industry, but a considerable part of the biomass is inedible. In this study, the pretreatment and saccharification parameters NaOH solution, pretreatment duration and enzyme load were evaluated for the production of hydrolysates from green coconut mesocarp using 18% (w/v) total solids (TS). Hydrolysates were not detoxified in order to preserve sugars solubilized during the pretreatment. Reduction of enzyme load from 15 to 7.5 filter paper cellulase unit (FPU)/g of biomass has little effect on the final ethanol titer. With optimized pretreatment and saccharification, hydrolysates with more than 7% (w/v) sugars were produced in 48h. Fermentation of the hydrolysate using industrial Saccharomyces cerevisiae strains produced 3.73% (v/v) ethanol. Our results showed a simple pretreatment condition with a high-solid load of biomass followed by saccharification and fermentation of undetoxified coconut mesocarp hydrolysates to produce ethanol with high titer.

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The residual biomass obtained from the production of Cocos nucifera L. (coconut) is a potential source of feedstock for bioethanol production. Even though coconut hydrolysates for ethanol production have previously been obtained, high-solid loads to obtain high sugar and ethanol levels remain a challenge. We investigated the use of a fed-batch regime in the production of sugar-rich hydrolysates from the green coconut fruit and its mesocarp. Fermentation of the hydrolysates obtained from green coconut or its mesocarp, containing 8.4 and 9.7% (w/v) sugar, resulted in 3.8 and 4.3% (v/v) ethanol, respectively. However, green coconut hydrolysate showed a prolonged fermentation lag phase. The inhibitor profile suggested that fatty acids and acetic acid were the main fermentation inhibitors. Therefore, a fed-batch regime with mild alkaline pretreatment followed by saccharification, is presented as a strategy for fermentation of such challenging biomass hydrolysates, even though further improvement of yeast inhibitor tolerance is also needed.

In the present paper, a high energy milling process has been used to alloy Fe and B in the proportion 2:1. X-ray diffraction and Mössbauer spectroscopy were used to follow the solid state reaction among the alloy components and phase formation during thermal treatments of the final milled alloy, at distinct temperatures and environments. X-ray, DSC and Mössbauer data of the 310 h milled alloy show the presence of three phases: small fractions of α-Fe (n-Fe) and Fe 2 B (n-Fe 2 B) nanocrystalline phases and a large amount of amorphous Fe 2 B (a-Fe 2 B) phase (73%). Heat treatment of the milled alloy was done in a high vacuum furnace, followed by in situ Mössbauer measurements, or by annealing the sample sealed in a quartz tube. It is shown that segregation and crystallization effects thermally induced in the samples have been enhanced by the presence of oxygen in the residual atmosphere, being less effective in the case where the sample was continuously pumped during the annealing. These effects may have occurred due to boron oxidation. Also, the presence of a tet-Fe 3 B phase in the annealed samples has been observed. The high temperature Mössbauer spectra for the sample annealed at 823 K indicate that the n-Fe 2 B, n-Fe 3 B and n-Fe phases exhibit superparamagnetic behaviour, with estimated blocking temperatures of 723 and 823 K, respectively. The amorphous a-Fe 2 B phase has a T C value estimated at about 823 K that fits into the system reported for amorphous Fe/B ribbons.

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