Quantitative and qualitative analysis of bacterial and fungal flora and total volatile nitrogen of extruded aquatic food with emphasis on clean industry

Dissertation for M.Sc. degree

Treatment: food industry

Abstract

Quantitative and qualitative analysis of bacterial and fungal flora and total volatile nitrogen, 6 types of commercial food, extruded (floating) produced in Mazandaran province, including: starters 1 and 2, growth and finishers 1, 2 and 3, in a period of 90 days (0, 30, 60, and 90) were examined. The amount of organic compounds (protein, fat and carbohydrate) in the food varied between 48-37, 18-15 and 19-13.5%, respectively. Fish powder, soy, wheat gluten, corn gluten, flour, unsaturated fats, antioxidants, preservatives, mixed vitamins and minerals, binders, multi-enzymes, toxin absorbents and salt were used in the formulation of all of them. The results showed that the minimum number of bacteria in the 6 types of food examined, at zero time, in two treatments 1 and 2 (starters 1 and 2) were 2.57x 102 and 2.90x 102, respectively, in treatments 4, 5 and 6 were 5.16x 102, 6.74x 102 and 8.10x 102, respectively. In treatment 3 (growth) 2.73 x 102 per gram of food and the maximum number of bacteria in 90 days, in two treatments 1 and 2 (starters 1 and 2) 4 x 23.104 and 83.4 x 104 respectively, in treatments 4, 5 and 6 respectively 6.30 x 104, 104 x 3.8 and 104 x respectively 7/8 and in treatment 3 (growth) 104x 6/03 per gram of food was recorded. The identified bacterial isolates included Aeromonas sp., Staphylococcus sp., Micrococcus sp., Bacillus sp., and Enterobacteriaceae, and Gram-positive bacteria such as Micrococcus, Staphylococcus, and Bacillus were the most abundant. The minimum number of mushrooms at zero time in two treatments 1 and 2 (starters 1 and 2) is 1.9x102 and 10.2x102, respectively, in treatments 4, 5 and 6, 3.06x102, 3x902, and 10.4x102, respectively, and in treatment 3 (growth) 2x40.102 per gram of food. And the maximum number of mushrooms in 90 days in treatments 1 and 2 (starters and 2) was 4.26 x 103 and 4.5 x 103, respectively, treatments 4, 5 and 6 were 5.103 x 5.103, 5.9 x 103 and 6.9 x 103 respectively, and in treatment 3 (growth) 4 x 102 x 6.4 per gram of food. The identified fungi included: Fusarium, Penicillium, Rhizopus and Mucor. The amount of total volatile nitrogen increased with food storage time.

Key words: bacteria, fungi, extruded aquatic food, total volatile nitrogen

Chapter One

Introduction

11 Preface

Increasing day by day The population, especially in the developing countries, has driven the ever-increasing human need for new food sources. One of these sources is the breeding and production of aquatic animals, especially fish in inland waters, using the water of rivers, wells, springs, and salty waters of the southern shores of the Caspian Sea in the north, the Persian Gulf and the Oman Sea in the south, and on the other hand, many developed countries in the world supply a significant part of their protein consumption from these materials [1]. According to FAO statistics, the per capita consumption of fish in this group of countries has exceeded 16-17 kg, but this amount in our country is between 6-7 kg, which is significantly different from the global per capita consumption, and according to the latest statistics of the Iranian Fisheries Organization, the amount of aquatic catch in our country, marine fish and shrimp, including bony fish from the Caspian Sea, the Persian Gulf, and the Sea of ??Oman, and farmed fish, including cold water fish (rainbow trout) and Caspian Sea salmon), farmed carp, sturgeon and shrimp, taking into account the country's population (75 million people) and with the production of 450-525 thousand tons of marine and farmed fish, the amount of human consumption per capita is 6-7 kg per year, although this amount of consumption is higher in the southern and northern coastal provinces. (Explanation that the amount of exported fish and the amount of unusable fish that are allocated to the production of fish meal are not included in this statistic). Of this amount of fish production, 150 thousand tons are dedicated to rainbow salmon (ranked first in the world), more than 130 thousand tons to farmed carp, more than 20 thousand tons to shrimp and less than 500 tons to sturgeon, and in other words, more than 60% of per capita fish consumption in our country is farmed fish. The share of cold water fish, i.e. rainbow salmon, is more than 30%, and Mazandaran province plays a big role in providing human protein with more than 20 thousand tons of cold water fish production. Today, many people's needs are met through aquaculture, so that in 1997, about 66% of salmon production was met through aquaculture [2].. The benefits of seafood due to its high protein content, as well as fat-soluble vitamins (A) and D) and water-soluble vitamins (B groups), minerals (calcium and phosphorus and a small amount of iron, copper and selenium), fat and highly unsaturated fatty acids Omega 3 (EPA [1]) and Omega 6 (DHA [2]) and their beneficial and significant effects on human health, especially in preventing cardiovascular and cerebrovascular strokes and the accumulation of platelets in blood, reducing cholesterol, brain health, increasing IQ and preventing forgetfulness and Alzheimer's, identifying new sources of food to supply human protein and the existence of potential talents, i.e. abundant water resources (rivers, springs, wells, more than 3 thousand kilometers of water beaches in the north and south) and also the reduction of marine aquatic resources due to various reasons, has led us to fish farming in inland waters and coastal waters, because this is the only way to increase the per capita consumption of fish in our country. Dad, in order to get a better position for our country in the classification of rich countries, which is one of the indicators of protein consumption per capita, and on the other hand, to be among the rich countries. For this amount of farmed fish production (more than 300 thousand tons) in the first stage, at least 500 thousand tons of fish food is needed through fish food factories in the aquaculture industry, and if quality and health controls are not carried out in the process of producing this amount of food, it will directly threaten the health and safety of farmed fish and the health of humans indirectly.

12 Introduction

Feeding costs in aquaculture usually include more than 60% of the total costs. Therefore, the successful and economic breeding of fish and other farmed aquatic animals depends on the provision of suitable feeds according to the needs of that aquatic, because in the conditions of intensive fish breeding, it is only possible to provide the nutritional needs of the fish through manual feeding, although the fish (rainbow salmon, salmon, etc.) cannot provide their nutritional needs from their natural living environment, and on the other hand, in the breeding of carp fish, three types of phytofak fish, bighead and grass-eating fish are part of They can meet their nutritional needs from natural food inside the pool, although this situation also applies to common carp. Living pathogenic agents including microorganisms (bacteria, fungi, viruses and parasitic protozoa) and non-living (toxins produced in food by saprophytic fungi such as Fusarium, Aspergillus, Penicillium, Mucor and Rhizopus) can threaten the health of farmed fish in several ways: 1- Contact with the water of the breeding environment 2- Food consumed 3- Through eggs and sperm Breeding fish (such as some viral and bacterial diseases [3]. The two ways of transmitting pathogenic agents to farmed fish, including cases 1 and 3, are not included in our review and study, and only the transfer of fungal and bacterial agents through commercial food used in aquaculture, which today more than 95% is used in the form of extruded dry food (floating and semi-floating) has been investigated and studied.

Abstract: Qualitative & Quantitative analysis of bacteria & fungal flora & total volatile nitrogen, 6 kinds of commercial food, of extruder (submerged) kind produced by Mazandran province including: starter 1 & 2, growth & termination 1, 2 & 3 have been studied during a 90 period (0,30,60,90). the organic compounds level (protein, lipid & carbohydrates) of the food have varied ranging 37-48, 12-18, 5-13/19%, respectively. In the formulation of all of them fish meal, soy, wheat gluten, maize gluten, flour, unsaturated fat, antioxidants, preservative, a combination of vitamin & mineral, binder, multienzymes, toxin absorbent and salt have been used.  the results imply the minimum bacteria number in 6 kind of the study food at time 0 in the two treatments 1 & 2 (starter 1 & 2) have been respectively 2.57×102 & 2.90×102, in treatment 4, 5 and 6, as 5.16×102, 6.74×102 & 8.10×102 and in treatment 3 (growth) ), 2.73×102 per gram food & the maximum bacteria number for 90 day period, in tow treatment of 1 & 2 (starter 1 & 2) were recorded 4.23×104...& 4.83×104, in 4, 5 and 6, 6.30×104, 8.3×104 and 7.8×104 and in treatment 3 (growth), 6.03×104 per gram of food. the bacteria strains have been identified including Aeromonas SP.