Raw lactose was obtained on filter-centrifuge or vacuum filter from whey concentrate (45–65% dry weight) and processed by pre-crystallization and purified into lactose. Milk or whey from dairy industry waste was concentrated with vacuum evaporator at 20☌. However, further studies are required for testing tuna protease as rennet substitute on an industrial scale. (1997) isolated tuna fish gastric proteases using 25% NaCl solution (w/v) at different holding times (0–3 h), prior to the enzyme activation at pH 5.0, that can be used as an alternative to rennet substitutes. The extraction of milk-clotting enzymes from fish stomach mucosa for cheese manufacture would provide an inexpensive alternative to rennet substitutes for domestic use or to export to cheese-producing nations and would become a new food-related industry. Farms and industry require reliable information on the contamination level in milk, based on measurements, in order to decide whether milk should be used in dairy production or be disposed of as waste ( Rantavaara et al., 2005). Production on farms should be the first target of countermeasures for the safety of food. The food processing industry has its own demands concerning the safety of foodstuffs it receives from primary production. Arvanitoyannis, Aikaterini Kassaveti, in Waste Management for the Food Industries, 2008 Food industry (2010) who found cofermentation of cattle manure with alperujo a suitable treatment option yielding biogas and fertilizer. While AD of olive mill effluents has proven feasible in combination with cattle manure, household waste, sewage sludge, poultry manure, wine-grape and slaughterhouse wastewater, and laying hen litter, there are only few studies that have shown the codigestability of two-phase olive mill wastes (TPOMW, alperujo) for example, Goberna et al. Alperujo may be composted and yields good quality in terms of nutrient content, stabilized and nonphytotoxic organic matter, and low heavy-metal contents best suited as a soil amendment ( Alburquerque et al., 2011). Recently, the trend points toward the production of alperujo, wet solid lignocellulosic material also containing mashed olive stones.
Due to different ways of extraction of oil from olives, different waste streams are known. One example from the food industry is olive oil production.
Often, the production of biomethane, and a solid–liquid separation of the digestate make sense for its further utilization, for example, after a stabilization process by composting.
The problem with the utilization of such wastes is often their centralized availability, incurring high transportation costs. Judith Ascher-Jenull, in The Future of Soil Carbon, 2018 Wastes from the Food IndustryĪmong food-processing industry-derived wastes the main waste streams are fruit-and-vegetable wastes, wastes from dairy, olive oil, fermentation industries, meat, poultry, and seafood by-products ( Kosseva, 2009, 2013) along with vast volumes of aqueous wastes ( Grismer et al., 2002).