Exploitaion And Its Practices Of Apple Pomace As A Resource

China is the apple producer ranking first in the world and its planting area and yield of apple separately account for one third of the totals of the world. In 2002, its annual apple yield reached 20 510 000 tons accounting for35.4% of the total of the world (FAO). In 2006, its annul apple yield reached 24 000 000 tons—20 060 000 tons. Thus, it has remarkable comparative advantages in apple production. The major approach for China to transform its resource advantages into economic advantages is to process concentrated apple juice and its current yield of concentrated apple juice amounts to nearly 600000 tons, separately accounting for 1/2 of the world's total yield and trading volume of concentrated apple juice and ranking first in the production and trade of concentrated apple juice in the world. However, compared with developed countries, China has a poorly-developed and low-efficiency apple processing industry in which the problem of poor apple pomace exploitation appears prominent and constrains apple industry to some extent. Having proceeded from the realities in apple industry and agricultural production of China, the study researched on pomace preservation and storage, direct pomace feeding, and production of microbial protein feeds with pomace, technology of apple-seed oil processing and quality evaluation of apple seed oil, polyphenol production with pomace, and anti-oxidative properties of apple pomace considering social demands, actual research conditions and current pomace exploitation. Its results were as follows:1. Apple pomace contained certain amounts of moulds and yeasts, extremely small amounts of actinomycetes and higher amounts of bacteria. After having been fermented, it contained only yeasts, acetobacters and lactic acid bacteria (Lactobacillus). The storage of apple pomace by anaerobic fermentation was not only secure and reliable but also beneficial. The storage by fermentation can preserve apple pomace for more than 12 months without quality deterioration.2. After having been fermented, apple pomace increased both its protein content and its calorific value greatly. Of the fermentation methods, plastic film-covered fermentation could make apple pomace have the highest protein content and the highest calorific value, which were 7.86% and 4564 Cal/g, respectively. While chicklings were daily fed with apple pomace-added feed, they grew uniformly and healthily, presenting high survival rate and high feed transformation rate. Fermented apple pomace by plastic film-covered fermentation showed the best effect in chickling feeding.3. During its fermentation, apple pomace could produce lixivium that accounted of 15% of its total. The main organic acids of the lixivium were acetic acid (45.840% of the organic acid total), lactic acid (44.746% of the organic acid total) and followed by malic acid, oxalic acid and tartaric acid and succinic acid in small quantities. The lixivium contained abundant polyphenols and flavonoids thus presenting certain antioxidation, and as a result it had such effects as decreasing cholesterol and triglyceride contents in blood serum of mice and improving fatigue-tolerating capacity of mice.4. Amidst apple seed oil, linoleic acid (C18:2) occupied 23%, oleic acid(C18:1) occupied 39.69%, palmitic acid (C16:0)occupied 7.09%, stearic acid(C18:0) occupied 2.37% , and arachidic acid (C20:0)occupied 0.91%.5.The oil-extracting rate of apple seeds was 18.3% by common solvent extraction, 21.4% by aqueous enzymatic method, and 20.9% by ultrasound-assisted extraction.6. The optimized conditions of extracting polyphenols from apple pomace by ultrasound extraction were that the solvent concentration(V/V)was70%, the ultrasound power was 225W and the action duration of ultrasound was 20min; the apple pomace[weight(w), g] to methanol [volume(v), ml] ratio was 1:20 and the extraction was repeated two times. Under the conditions, the polyphenol extracting rate of apple pomace was 1705mg/kg.7. The polyphenols extracted from apple pomace had strong capacities of eliminating or inhibiting superoxide anion (02-·) and hydroxyl free radical(·OH). They could remarkably increase the antioxidative capacities of greases. The extracts extracted with methanol showed the best effect in eliminating free radicals and the extracts extracted with acetone showed the poor effect in antioxidation. The polyphenols extracted from apple pomace performed better in eliminating superoxide anion (02-·) and hydroxyl free radical(·OH) than BHT.8. The polyphenolic acids were identified by high performance liquid chromatography to be gallic acid, protocatechuic acid, chlorogenic acid, caffeicum acid, syringic acid, p-cinnamic acid, vanillin acid and ellayic acid. What some peak areas stood for could not be identified and thus needed to be further studied.9. The mixed fermentations of apple pomace with different combinations of Rhizopus, Geotrichum candidum and endomycetaceae could greatly increase its protein contents. The technological conditions of the optimized mixed fermentation were that the inoculum-size ratio of Rhizopus, Geotrichum candidum and Endomycetaceae was 1:1:1 in the same order, the total inoculum-size occupied 15%, the urea input occupied 2.5%, the ammonia sulfate input made up 2.5%, and the fermentation temperature was 32℃, the apple pomace to bran ratio was 85:15, and the water content of material was approximately 65%, the incubation duration of the thin layer fermentation lasted 72 hours. The fermentation product contained 18% real protein or more.10. Under proper conditions, microbial protein feeds could be manufactured with dry apple pomace for which Aspergillus niger was used as its leavening inoculum, and in this way they contained greatly increased protein contents. The optimized fermentation conditions were that the dry apple pomace to water ratio was 1:1, the urea input made up 7%, , the temperature was 30℃, the ventilated thin layer fermentation lasted seven days. The fermentation products contained 19% real protein or more.11. Three large-scale thickly-stacked fermentations of fresh apple pomace were carried out in Haisheng Company (Qianxian County). They proved that the fermentation process was stable and highly repeatable, and the fermentation product contained more than 20% real protein.