Environmental impact of castor oil catalytic transfer hydrogenation

In the vegetable oil chemical industry, hydrogenation is one of the most important processes. An alternative method for vegetable oil hydrogenation is the use of catalytic transfer hydrogenation (CTH), which can utilize organic molecules as hydrogen donors at ambient pressure. These alternative processes should be optimized in relation to the variables required for a good conversion and impacts should also be known to be minimized. An assessment of the environmental impact of laboratory scale chemical processes is an important tool to improve the technological aspects of a process (increased yields, reduced production times, lower costs) and it can also lead to the creation of a cleaner technology. Using the Leopold Matrix, we have succeeded in developing a more efficient and cleaner process for the CTH of castor oil using Raney Ni as a catalyst and cyclohexene or isopropanol as a hydrogen donor solvent. The results of the technical and environmental assessments showed that the extent of conversion for the unsaturation reaction was high (>99 %), and the environmental impact of the process could be significantly reduced to create a cleaner technology. It was found, after process optimization, that the remaining environmental impacts were negative (67.48 %), local (78.95 %), temporary (95.33 %), direct (80.12 %), and reversible (95.32 %).     

Whey filtration: a review of products,application, and pretreatment with transglutaminase enzyme

In the cheese industry, whey, which is rich in lactose and proteins, is underutilized, causing adverse environmental impacts. The fractionation of its components, typically carried out through filtration membranes, faces operational challenges such as membrane fouling, significant protein loss during the process, and extended operating times. These challenges require attention and specific methods for optimization and to increase efficiency. A promising strategy to enhance industry efficiency and sustainability is the use of enzymatic pre-treatment with the enzyme transglutaminase (TGase). This enzyme plays a crucial role in protein modification, catalyzing covalent cross-links between lysine and glutamine residues, increasing the molecular weight of proteins, facilitating their retention on membranes, and contributing to the improvement of the quality of the final products. The aim of this study is to review the application of the enzyme TGase as a pretreatment in whey protein filtration. The scope involves assessing the enzyme's impact on whey protein properties and its relationship with process performance. It also aims to identify both the optimization of operational parameters and the enhancement of product characteristics. This study demonstrates that the application of TGase leads to improved performance in protein concentration, lactose permeation, and permeate flux rate during the filtration process. It also has the capacity to enhance protein solubility, viscosity, thermal stability, and protein gelation in whey. In this context, it is relevant for enhancing the characteristics of whey, thereby contributing to the production of higher quality final products in the food industry. © 2023 Society of Chemical Industry.     

Progressive inclusion of pearl millet herbage as a supplement for dairy cows fed mixed rations: Effects on methane emissions,dry matter intake,and milk production

The inclusion of grazing in dairy feeding systems can improve animal welfare and reduce feed costs and labor for animal care and manure management. This work aimed to evaluate the effects of including pearl millet herbage (Pennisetum glaucum ‘Campeiro') as a supplement for dairy cows fed total mixed rations (TMR). The treatments included 100% TMR offered ad libitum (control, TMR₁₀₀), 75% TMR ad libitum intake + access to grazing of a pearl millet pasture between the morning and afternoon milkings (7 h/d; pTMR₇₅), and 50% TMR ad libitum intake + access to grazing of a pearl millet pasture between the morning and afternoon milkings (7 h/d; pTMR₅₀). Nine multiparous Holstein and F₁ Jersey × Holstein cows were distributed in a replicated 3 × 3 Latin square design with 3 periods of 21 d (a 16-d adaptation period and a 5-d measurement period). Cows in the TMR₇₅ and TMR₅₀ groups strip-grazed a pearl millet pasture with pre- and postgrazing sward height targets of 60 and 30 cm, respectively. The herbage dry matter intake (DMI) increased with decreasing mixed ration supplies, and the total DMI decreased linearly from 19.0 kg/d in the TMR₁₀₀ group to 18.0 kg/d in the pTMR₅₀ group. Milk production decreased linearly from 24.0 kg/d in the TMR₁₀₀ group to 22.4 kg/d in the pTMR₅₀ group, and energy-corrected milk (ECM) production decreased linearly from 26.0 kg/d to 23.6 kg/d. Enteric methane (CH₄) emissions decreased linearly from 540 g/d in the TMR₁₀₀ group to 436 g/d in the pTMR₅₀ group, and CH₄ yields (g/kg of DMI) tended to decrease linearly. The CH₄ intensity was similar between treatments, averaging 20 g of CH₄/kg of ECM. The inclusion of pearl millet herbage in the dairy cow diets decreased the total DMI and milk production to a small extent without affecting CH₄ intensity (g/kg of ECM).     

Natural Ventilation by Air Captors and Extractors Sheds in Hospitals in Brazil： Wind Tunnel Measurements

Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures consist of roof openings that work as air captors or extractors depending on their location in relation to the prevailing wind directions. The hospitals of the Sarah Network, designed by the Brazilian architect Joao Filgueiras Lima, Lele, are worldwide known for using these elements to improve natural ventilation. This paper analyses the natural ventilation performance of sheds for air collecting and extracting in two Sarah hospitals located in the cities of Salvador and Rio de Janeiro. In each building, the sheds were analyzed for air extracting and collecting. The analyses were carried out by reduced physical models in an atmospheric boundary layer wind tunnel. The wind velocity was measured at external and internal points of the buildings, using hot-wire anemometers. The results show that the wards in Rio de Janeiro hospital are 17% more ventilated than the ones in the Salvador hospital. However, this difference occurs not only because of the collecting sheds but also because of set of openings and the configuration of the covering in hospitals in Rio de Janeiro.     

Evaluation of CO2 absorption and desorption rate in oysters (Cassostrea gigas) using the soluble gas stabilisation method

Soluble gas stabilisation (SGS) is a recently proposed method to extend the shelf life of food. However, no studies have determined the amount of carbon dioxide absorbed in food and particularly in oysters. Thus, the aim of this study was to determine CO₂ absorption and desorption rates in oysters during the solubilisation process. Cooked oysters were placed in the apparatus's chamber, CO₂ was injected into the chamber, and the SGS process started at different pressures, temperatures and gas/product (g/p) ratios. CO₂ absorption and desorption rates were obtained from data of CO₂ concentration in the chamber headspace and calculated by mathematical models. The results showed higher absorption rates under higher pressure, higher g/p ratio and lower temperature (0 °C). The concentration of CO₂ dissolved in the oysters was 21008.45 mg CO₂ kg product^?1. On the other hand, lower desorption rates occurred for the lowest pressure (200 kPa) and lowest gas/product ratio (1:1). For CO₂ desorption from oysters, it was observed that 10 min was enough to desorb a large amount of CO₂ under normal atmosphere.