Characterization of enzymatic hydrolyzed snow crab (Chionoecetes opilio) by-product fractions: A source of high-valued biomolecules

Snow crab (Chionoecetes opilio) constitutes valuable and nutritional sources of components, such as proteins, lipids and chitin. The present investigation was undertaken to evaluate the feasibility of applying a pilot scale enzymatic hydrolysis process of snow crab by-products, followed by fractionation, in order to recover enriched high-valued compounds. The yield of snow crab by-products recovered after manual processing; on a dry weight was 87.4%. The by-products (raw materials) were mainly moist (approximately 78%), and contained 42.9% proteins, 14.8% lipids, 25.7% minerals, 16.2% chitin, all expressed on a dry weight. The fatty acid profile of snow crab by-products and all fractions obtained following processing showed a higher content in mono-unsaturated fatty acids (MUFAs; approximately 50%), followed by polyunsaturated fatty acids (PUFAs; approximately 20%) and saturated fatty acids (SFAs; approximately 15%). The n − 3/n − 6 ratio was approximately 10 and represents a good index of nutritional value for snow crab oil by-products. Most protein enriched fractions demonstrate a well-balanced amino acid composition, notably the most essential amino acids. These protein fractions are characterized by biomolecules having a relatively low molecular weight (35 kDa and less) range. The enzymatic hydrolysis process developed in this study shows that snow crab by-products should to be viewed as having the potential of being identified as high-valued products. Even though the process could be optimized, it is controllable, and depending on hydrolyses conditions, the products obtained are reproducible and well defined. Results presented in this study indicate that snow crab by-products may serve as excellent nutritional components for future applications in the health and food sectors.     

Proteolytic Extraction of Salmon Oil and PUFA Concentration by Lipases

Commercial proteases (Alcalase^®, Neutrase^®, and Flavourzyme^™) were tested for their ability to release the oil content of marine by-products (salmon heads). The amount of oil (17%) obtained after 2 hours was close to that obtained by the chemical extraction method (20%). Lipolysis of the oil was carried out with Novozym SP398 to obtain a mixture of free fatty acids and acylglycerols (24 hours 45% hydrolysis). The mixture was filtered on a hydrophobic membrane to discriminate between high melting saturated fatty acids and low melting acylglycerols. The sum of total polyunsaturated fatty acids increased from 41.6% in the crude oil to 46.5% in the permeate. The docosahexaenoic acid content increased from 9.9% to 11.6%, and the eicosapentaenoic acid changed from 3.6% to 5.6%. Data from differential scanning calorimetry DSC and from thin layer chromatography coupled with flame ionization detection (TLC-FID) differed significantly between permeate and retentate. A re-esterification of the free fatty acids in the permeate with Lipozyme IM was carried out to increase the amount of long chain acylglycerols.     

An optimization study of carotenoid production by Rhodotorula glutinis DBVPG 3853 from substrates containing concentrated rectified grape must as the sole carbohydrate source

A multivariate statistical approach was employed for the optimization of conditions for carotenoid production by Rhodotorula glutinis DBVPG 3853 from a substrate containing concentrated rectified grape must as the sole carbohydrate source. Several experimental parameters (carbohydrate, yeast autolysate and salt concentrations, and pH) were tested at two levels by following a fractional factorial design. Carotenogenesis was most sensitive to both initial pH and yeast autolysate concentration. A Central Composite Design experiment was then performed by obtaining both second-order polynomial models and isoresponse diagrams where initial pH and yeast autolysate concentration were considered as variables. In this way it was possible to determine the conditions (pH = 5.78, yeast autolysate = 4.67 g L⁻¹) which maximize both the concentration of total carotenoids and that of β-carotene (6.9 mg L⁻¹ and 1100 μg L⁻¹ of culture fluid, respectively, after 120 h of fermentation). Journal of Industrial Microbiology & Biotechnology (2000) 24, 41–45. Received 23 February 1999/ Accepted in revised form 14 September 1999     

Effect of ultrasound and addition of bacterial product on hydrolysis of by-products from the meat-processing industry

The hydrolysis efficiency of ultrasound (US) and bacterial product (BP; Liquid Certizyme 5™) was studied as a pre-treatment for anaerobic digestion (AD) of four animal by-products (ABP) from the meat-processing industry (digestive tract content + drumsieve waste, dissolved air flotation (DAF) sludge, grease trap sludge and the mixture of these). The change in volatile solids (VS) based hydrolysis parameters was screened using different specific US energy (Es) inputs (1000-14,000 kJ/kg of total solids (TS)) and durations of BP treatment (3-48 h). The Es of 6000-8500 kJ/kg TS increased most extensively the soluble chemical oxygen demand (COD_sol) and VS ratio, by 45-290%, and soluble nitrogen (N_sol) by 44-99%. Simultaneously, the average particle size (APS) decreased by 45-75%, from the original value. With BP, the highest increases in COD_sol/VS (29-130%), N_sol (35-63%) and decline in APS (40-70%) depended on the raw material (digestive tract content + drumsieve waste: 3 and 24 h; DAF sludge: 3 and 6 h, mixture: 12 and 48 h). BP apparently was more effective at hydrolyzing smaller cellulose particles, while US appeared to enhance the degradation of grease-containing cells.     

Market Processes and the Closing of 'Industrial Loops'

Many industrial ecologists assume that traditional economic development was characterized by a linear approach in which materials and energy were extracted, processed, used, and dumped in a linear flow into, through, and out of the economy. Much historical evidence, however, indicates that industrial resource recovery was much more widespread than currently thought. This article reviews the available evidence by introducing the reader to earlier literature on the topic and by providing a short case study of animal by-products recovery from the Neolithic period to the middle of the twentieth century. The main finding of this article is that the belief that market actors systematically failed to close "industrial loops" in earlier eras is inaccurate. Furthermore, it is pointed out that the industrial ecology metaphor was actually well understood in the middle of the nineteenth century.     

Biodegradation of automotive waste polyester polyurethane foam using Pseudomonas chlororaphis ATCC55729

Automotive waste polyester polyurethane (PUR) foams represent a major solid waste management problem. In the present investigation, we examined the capacity of Pseudomonas chlororaphis ATCC 55729 to biodegrade waste polyester PUR foam obtained from an automotive industry in shake cultures. Ammonia nitrogen, pH and diethylene glycol (DEG) concentrations were found to increase steadily over a period of 12 days. Furthermore, scanning electron photomicrographs of foam pieces also showed evidence of biodegradation. This shows that waste PUR foams can be successfully biodegraded under controlled laboratory environment.     

The Fatty Acid Composition and Quality of Oils from Post‐Industrial Waste of Quince Chaenomeles japonica

In the food industry, quince seeds are discarded as waste in the production process. Their use therefore creates added value and opens up the possibility of using no‐waste processing technologies. Three types of waste were investigated: after juicing, after the manufacture of puree and syrup. The results showed that the yield of quince seeds (Chaenomeles japonica (Thunb .) Lindl . ex Spach from waste left after different production methods varies from 29.8 to 38.3 %. The cold pressed oil yield ranges from 4.9±0.03 to 7.1±0.06 %. The oil yield obtained by Soxhlet extraction varies from 14.6±0.64 to 17.3±0.9 %. Unsaturated fatty acid, especially polyunsaturated fatty acid is predominant in quince seed oil. The linoleic acid content of the quince seed oils was between 47.12 % and 58.49 % of the total fatty acids. The fatty acid composition of oils from post‐industrial waste is more appropriate in the skin care industry than in the food industry because of the high ratio of omega‐6/omega‐3 and high linoleic acid content.     

Alkaline preserved herring by-products in feed for Atlantic salmon (Salmo salar L.)

The aim of the present study was to investigate the digestibility, growth and slaughter quality in Atlantic salmon (Salmo salar L.) fed a novel type of moist feed. The moist feed was prepared from alkaline preserved (pH 11.2) herring (Clupea harengus) filleting by-products, mixed with a crude binder based on seaweed before the feed was shaped in a pelleting process and the final structure was set immersing the pellets in an acidic bath. The feeding experiment was carried out with seawater-adapted salmon with an average initial weight of 1.7 kg. The moist feed and a control feed were fed to three groups of salmon with 190 fish per group. The coefficient of total tract apparent digestibility of fat, protein and energy in fish fed the moist feed was 0.96, 0.81 and 0.87, respectively. The weight gain for fish fed moist feed was significantly higher compared to salmon fed commercially extruded control feed. Carcass quality data showed that fish fed the moist feed had significantly higher dressing out percentage and less visceral fat compared to fish fed the control feed. It is concluded that alkaline preserved fish by-products can be efficiently utilized in a novel moist feed technology, yielding good growth and digestibility in Atlantic salmon.     

玉米秸秆酸解副产物对重组酿酒酵母6508-127发酵的影响

将木质纤维素类生物质如玉米秸秆等用稀酸水解预处理,在半纤维素水解为单糖的同时,水解液中还会产生一些可能对后续发酵有影响的副产物。本实验分别考查了在玉米秸秆稀酸水解液中检测出的乙酸、甲酸、香草醛、糠醛和羟甲基糠醛对重组木糖发酵菌株S. cerevisiae 6508-127生长和发酵的影响。结果表明,甲酸和乙酸对菌体生长的抑制强于乙醇生成,且甲酸的抑制程度远大于乙酸;2g/L香草醛可使菌体生长延滞期明显延长,而在较低浓度（≤1.2g/L）此现象不明显。糠醛在0.5-1.5g/L范围内对菌体生长有抑制作用,但使乙醇得率提高;羟甲基糠醛在0.2g/L浓度存在就使乙醇得率有明显降低,但使生物量得率提高;研究中还发现,糠醛、羟甲基糠醛和香草醛可被S. cerevisiae 6508-127代谢。