Effect of some Engineering Factors on The Fish Silage Making تأثیر بعض العوامل الهندسیة على تصنیع سیلاج الأسماک

Abstract

The study aims to effect of engineering factors, types of fish waste and types of acid on fish minced to make acid silage met the criteria of low cost and low technology process. The results of experiment (1) showed that, the best treatment for making fish silage was the treatment (conical cutter knife, die of 3 mm diameter and mixing between tilapia fingerlings and catfish), because it gave the highest soluble solids content (14g/100g minced fish), as well as obtaining silage with a high degree of smoothness, which helps the speed of action of the enzymes liquefaction silage. The results of experiment (2) also showed that, the best results when using mineral acid to acidify the silage mixture was obtained with sulfuric acid. These acids produce higher soluble solid content (10.2 g/100g minced fish) and there is little loss of total solid about (1.52 %). The best results when using organic acid was obtained with acetic acid. These acids produce higher soluble solid content (12.3 g/100g minced fish) and there is little loss of total solid about (7.82 %). The best results when using mineral-organic acid combination was produced using sulfuric-acetic acid combination and produced the highest soluble solids content (17g/ 100g minced fish) and loss of total solids about (5 %). The studies indicate that, in general, a good acid silage should be made by adding 3.5 % combination between sulfuric acid and acetic acid until the pH of 4 keeping the mixture at 33 °C for 30 days.