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A logger enabling continuous measurement of corrosion rate of selected metals in indoor and outdoor atmospheres has been developed. Principle of the measurement method is based on the increasing electrical resistance of a measuring element made of the material concerned as its cross-sectional area diminishes due to corrosion. Zinc, iron, copper and nickel sensors at several thicknesses are available. Sensitivity of the corrosion measurement varies from 1 to 10 nm depending on the type and thickness of the sensor. Changes in the air corrosivity can be thus detected within hours or even tens of minutes. The logger lifetime in medium corrosive environments is designed to be 2 years with full autonomy. Data on the sensor corrosion rate are available any time through GPRS connection or by a non-contact inductive reading without the need of retracting the logger from the exposure site.

As a consequence of the increased demand for proteins for both feed and food, alternative protein sources from green plants such as alfalfa (Medicago sativa) have come into focus, together with methods to recover these proteins. In this study, we have investigated the use of screw presses for protein recovery from alfalfa at laboratory and pilot scale. We found that using a pilot scale screw press, with a working pressure of 6 bar, 16% of the total protein was recovered in one pressing, and that after rehydrating and repressing the alfalfa up to ten times, 48% of the total protein could be recovered. The green alfalfa protein concentrate was analyzed for total protein, amino acid profile, protein digestibility, color, ash, fiber and fat content. It was found that repetitive pressings lowered the digestibility of the protein pool and reduced the total protein concentration due to dilution. To achieve the best quality protein at the highest concentrations, it is recommended to press the alfalfa no more than twice, which results in an alfalfa protein concentrate with more than 32% soluble protein and greater than 82% digestibility.

In this study, the potential of alfalfa pulp as an alternative substrate to wheat straw for the cultivation of oyster mushroom (Pleurotus ostreatus) was investigated. The major components associated with different mushroom stages were evaluated, as well as changes in lignocellulolytic enzyme activities in substrates composed of alfalfa pulp, wheat straw or a combination of both. Based on the results, alfalfa pulp was demonstrated to be a better substrate than wheat straw for the production of oyster mushrooms, with a high biological efficiency of 166.3 ± 25.4%. Compared to the cultivation period on commercial straw (31 days), a shorter lifecycle for oyster mushroom was found on alfalfa pulp (24 days), which could help to reduce the risk of contamination during industrial production. Study of the spent substrate as well as the harvested mushrooms revealed that the biological efficiency was related to the higher protein content (17.42%) in the alfalfa pulp compared to wheat straw, as well as greater degradation of cellulose (57.58%) and hemicellulose (56.60%). This was, by and large, due to greater extracellular hydrolytic and oxidative enzyme activity from the mushroom growth in the alfalfa pulp. The quality and safety of the fruiting bodies produced on alfalfa pulp was evaluated, which showed that the protein content was 20.4%, of which 46.3% was essential amino acids, and levels of trace elements and heavy metals were below acceptable limits. Hence, oyster mushroom cultivation using alfalfa pulp provides an alternative method to produce a value-added product, while reducing the biomass wastes in the green protein bio-refinery, and may contribute to sustainable growth in the agricultural industry.

White alfalfa protein concentrate from alfalfa (Medicago sativa) is a promising substitute for milk and egg protein due to its functionality. However, it contains many unwanted flavours that limits the amount that can be added to a food without affecting its taste negatively. In this paper, we have demonstrated a simple method for the extraction of white alfalfa protein concentrate followed by a treatment with supercritical CO2. Two concentrates were produced at lab scale and pilot scale, with yields of 0.012 g (lab scale) and 0.08 g (pilot scale), of protein per g of total protein introduced into the process. The solubility of the protein produced at lab scale and pilot scale was approximately 30% and 15%, respectively. By treating the protein concentrate at 220 bar and 45 °C for 75 min with supercritical CO2, off-flavours were lowered. The treatment did not decrease the digestibility or alter the functionality of white alfalfa protein concentrate when it was used to substitute egg in chocolate muffins and egg white in meringues.