Characterization and evaluation of coconut aroma produced by Trichoderma viride EMCC-107 in solid state fermentation on sugarcane bagasse

Background: Sugarcane bagasse was shown to be an adequate substrate for the growth and aroma production by Trichoderma species. In the present work the ability of Trichoderma viride EMCC-107 to produce high yield of coconut aroma in solid state fermentation (SSF) by using sugarcane bagasse as solid substrate was evaluated. The produced aroma was characterized. Results: Total carbohydrates comprised the highest content (43.9% w/w) compared with the other constituents in sugarcane bagasse. The sensory and gas chromatography–mass spectrometric (GC–MS) analysis revealed that the highest odor intensity and maximum yield of volatiles were perceived at the 5th d of induction period. The unsaturated lactone, 6-pentyl-α-pyrone (6-PP), was the major identified volatile compound. Saturated lactones, δ-octalactone, γ-nonalactone, γ-undecalactone, γ-dodecalactone and δ-dodecalactone, were also identified in the coconut aroma produced during the induction period (12 d). A quite correlation was found between the composition and odor profile of the produced aroma. The effect of varying the concentration of sugarcane bagasse on 6-PP production and biomass growth was evaluated. The results revealed high 6-PP production at 4.5 g sugarcane bagasse whereas the biomass showed significant (P < 0.05) increase by increasing the concentration of sugarcane bagasse. Conclusion: The concentration of 6-PP, the most contribution of coconut aroma, produced in present study (3.62 mg/g DM) was higher than that reported in previous studies conducted under the same fermentation conditions. The significant increase in biomass with increasing the concentration of sugarcane bagasse may be attributed to the increase in sugar content that acts as carbon and energy source

Optimization of the production of roasted-nutty aroma by a newly isolated fungus Tolypocladium inflatum SRH81 and impact of encapsulation on its quality

Abstract Background Pyrazines are used in food industry to impart the foods nutty-roasted flavor. However, their extraction from natural sources is difficult and expensive. At the same time, there is awareness against the chemical food additives. Microorganisms are approved as natural producers of flavors. The aim of the present study was to assess the ability of the newly isolated fungus Tolypocladium inflatum SRH81 to produce pyrazines and studying the effect of encapsulation in gum Arabic on the quality of the biogenerated volatiles. The parameters affecting the biogeneration of pyrazines were optimized. The headspace volatiles of each culture were isolated and identified by solid phase microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS). The volatiles showed the highest pyrazines content and best nutty-roasty flavor was subjected to encapsulation. Results The selected fungus was identified as Tolypocladium inflatum SRH81. A high correlation was found between the consumed sugar and dry matter content of each culture. Incubation of the fungus culture enriched with 0.5 g amino acids/50 mL medium for 12 days at pH 8 showed the highest generation of pyrazines and best odor sensory quality. Nine pyrazines were identified among them 2-methylpyrazine was the major compound after incubation for 12 days. A positive correlation was found between the total pyrazines and intensity of roasty-nutty aroma. Encapsulation gave rise to a significant decrease in the total volatiles, while the odor intensity showed insignificant decrease. Conclusions The results of the present study revealed the potential ability of Tolypocladium inflatum SRH81, that was isolated from Egyptian soil, to produce pyrazines having roasted- nutty aroma

Improving the Antioxidant Activity of a Carbonated Lemon Soft Drink

The carbonated functional soft drinks are a new concept that provides health benefits for the consumers. The aim of this study was to improve the antioxidant activity of a carbonated lemon soft drink, while preserving its characteristic flavour, by blending the lemon oil (L) with oregano (Or) essential oil. The effect of different thickeners, usually used in formulation of the soft drinks, on release of the volatile compounds from simple model solutions was evaluated, separately. Blending lemon oil with oregano essential oil (1.5 µL Or /100 µL) improved the odour acceptability and increased the DPPH scavenging ability of lemon oil by 40%. Studying the effect of different thickeners indicated that the xanthan, Arabic gum and pectin at levels 0.05, 6.0 and 0.01 g/100 mL water, respectively, showed the highest release of limonene and citral, the most contributors to lemon aroma, from the simple model solutions. This finding was mainly correlated to the interaction between the thickeners. In view of this result a lemon soft drink was formulated. Carbonation of the soft drink improved the sensory characteristics, decreased the pH value, increased the acidity and showed insignificant changes (P &gt; 0.05) in total soluble solids and total sugars