Protein Fractionation of Green Leaves as an Underutilized Food Source—Protein Yield and the Effect of Process Parameters

Green biomass has potential as a sustainable protein source for human consumption, due to its abundance and favorable properties of its main protein, RuBisCO. Here, protein fractionation outcomes of green leafy biomass from nine crops were evaluated using a standard protocol with three major steps: juicing, thermal precipitation, and acid precipitation. Successful protein fractionation, with a freeze-dried, resolubilized white protein isolate containing RuBisCO as the final fraction, was achieved for seven of the crops, although the amount and quality of the resulting fractions differed considerably between crops. Biomass structure was negatively correlated with successful fractionation of proteins from biomass to green juice. The proteins in carrot and cabbage leaves were strongly associated with particles in the green juice, resulting in unsuccessful fractionation. Differences in thermal stability were correlated with relatedness of the biomass types, e.g., Beta vulgaris varieties showed similar performance in thermal precipitation. The optimal pH values identified for acid precipitation of soluble leaf proteins were lower than the theoretical value for RuBisCO for all biomass types, but with clear differences between biomass types. These findings reveal the challenges in using one standard fractionation protocol for production of food proteins from all types of green biomass and indicate that a general fractionation procedure where parameters are easily adjusted based on biomass type should instead be developed.

Combined Pretreatment as an Effective Technology in Breaking of Phenolic Polymer Lignin from Sustainable Biomass: Bambusa balcooa

Bamboo biomass is a potential source for the production of monomeric sugars containing high cellulose content with low amount of lignin. However, for efficient hydrolysis, the biomass treatment by effective pretreatment technique is required to minimize lignin content and other barrier components. During present study, the bamboo biomass was treated with different physical, chemical, biological and combined treatments to reduce the lignin content. Among all the pretreatments, the maximum lignin removal (14.5%) was obtained with the combined chemical and biological treatment under 2% NaOH+1% H2O2 +WDP2 fungal culture (5 plugs) conditions. In addition, lignolytic fungus and NaOH pretreatment was mainly effective in removing lignin, whereas the H2O2 pretreatment efficiently minimize cellulose crystallinity. To analyze structural changes of raw and treated biomass, we used scanning electron microscopy and fourier transform infrared spectroscopy. The structural analysis indicated that all treatments causes disruption in the biomass structure and loses the compactness of the biomass which facilitates the biomass conversion during hydrolysis process. The findings of the present study indicate effective pretreatment methods in breaching the recalcitrancy of the potential lignocellulosic biomass for maximum hydrolysis.

A VARIABILIDADE AMBIENTAL INFLUENCIA A COMPOSIÇÃO E BIOMASSA FITOPLANCTÔNICA DE UM RESERVATÓRIO NEOTROPICAL

Phytoplankton is an important model of the aquatic environments functioning, responding directly to environmental variability in space and time. Therefore, represents an excellent tool for the monitoring of reservoirs, which comprise highly heterogeneous ecosystems longitudinally, influencing the structure and distribution of phytoplankton species. The objective of this study was to investigate the variation in the composition and biomass of the phytoplankton in a reservoir in the Goiás state, Brazil, and how these organisms respond to environmental variability along the reservoir spatial extent in dry and rainy periods. The phytoplankton and environmental variables were collected during one dry period and other rainy, over seven sampling sites, distributed in the regions downstream of the dam, lacustrine, intermediate and lotic of the reservoir. The composition and biomass of the phytoplankton community were measured as a response to the spatial and temporal environmental variability. We recorded a spatio-temporal variation in water temperature, light, nutrients, and phytoplankton biomass. Cyanobacteria had the highest biomass in the lacustrine and intermediate regions, while diatoms in the lotic region, in both periods. The highest phytoplankton total biomass was recorded in rainy period. We recorded a clear relation between the phytoplankton biomass and the environmental variability, being that water temperature, turbidity and soluble iron the ones that showed the biggest influence on the biomass structure. Thus, the composition and biomass of the phytoplankton community can be important metrics of reservoirs functioning and, therefore, the phytoplankton study in these ecosystems it's of interest in their monitoring, since reservoirs have great ecological, economic or public health relevance

Exploration of Steam Explosion Treatment for the Recovery of Phenolic Compounds

<p>Steam explosion (SE) is a versatile tool for the pretreatment of lignocellulosic plant 27 materials and the further separation of their main constitutive components, <i>i.e. </i>cellulose, 28 hemicellulose, lignin, etc. In this study, we propose to evaluate the effects of SE 29 treatment on the recovery of secondary metabolites. As a case study, the well-known 30 grape pomace phenolic compounds were considered. Our results demonstrate that the 31 efficiency of the steam explosion in term of yield (900 mg polyphenols per kg of dry 32 grape pomace) was relatively similar to conventional maceration methods in alcoholic 33 media (800 mg/kg). Advantages of SE compared to maceration were highlighted: the 34 process is organic solvent free, destabilize the biomass structure and release insoluble 35 bound phenolic compounds. In addition, it offers the possibility to modulate distinct 36 polyphenols profiles by modifying the process conditions. </p>

Exploration of Steam Explosion Treatment for the Recovery of Phenolic Compounds

<p>Steam explosion (SE) is a versatile tool for the pretreatment of lignocellulosic plant 27 materials and the further separation of their main constitutive components, <i>i.e. </i>cellulose, 28 hemicellulose, lignin, etc. In this study, we propose to evaluate the effects of SE 29 treatment on the recovery of secondary metabolites. As a case study, the well-known 30 grape pomace phenolic compounds were considered. Our results demonstrate that the 31 efficiency of the steam explosion in term of yield (900 mg polyphenols per kg of dry 32 grape pomace) was relatively similar to conventional maceration methods in alcoholic 33 media (800 mg/kg). Advantages of SE compared to maceration were highlighted: the 34 process is organic solvent free, destabilize the biomass structure and release insoluble 35 bound phenolic compounds. In addition, it offers the possibility to modulate distinct 36 polyphenols profiles by modifying the process conditions. </p>