Preservative Efficiency of Allium Sativum on Shelf Life of Sea Water Fishes


 Natural preservation techniques of food are associated with various naturally producing antibacterial property of various biologically active compounds obtained from plants, spices, animals and microbes. Garlic (Allium sativum) is the prominent biologically active source possessing greater antimicrobial property. Expansion of shelf life, declines the spoilage mechanism by the use of garlic. Garlic exhibits not only preservative properties but also has a biological activity viz. antibacterial, antimicrobial, anti-inflammatory, antiprotozoal, anti-helminthic, antifungal, wound healing, antitumor, and insecticidal. Allyl alcohol, allicin is an active biological compound present in garlic. Fish is highly beneficial and wholesome food as it contains high quantity of proteins and minerals as compared to other meat sources. Fresh fishes easily deteriorate due to high moisture and nutrient content. Spoilage of food begins as soon as fish dies. Hence, many preservation techniques are used to escalate the shelf life of fish. Enzymatic action of bacteria do not cause any variation in the metabolic activities of living organisms due to its existing immunity against it. As soon as the fish perishes, the enzymes associated with the catalytic activities in flesh and guts are now responsible for the autolytic reaction. Decomposition can be identified by its color change, foul odor and its texture. Various physiological analysis of these fishes were done with respect to their weight, color, texture, softness, and appearance. Further on microbial analysis were performed to identify and characterize the fish isolate, followed by its biochemical test. Various parameters were evaluated with respect to quality and shelf life of fishes with and without garlic as the natural preservative.


Introduction
Natural preservation process implies the implementation of naturally occurring antimicrobial compound obtained from plant, animals and other sources to avert deterioration of food caused by microbial activities and increased food borne pathogens (Delesaet.al, 2018).
A top-notch biological active known is garlic (Allium sativum) which has a pronounced antimicrobial activity. It act as a dormant inhibitor for food pathogens. Utilization of garlic intensi es shelf life and shrinks the spoilage of food (Muhammad et.al,2016).
Garlic prevalently belongs to Liliaceae family. It is well-known medicinal plant, food item and spice in different areas (Shivenduet.al,2012). This not only possess preservative attributes but also exhibit various biological activity such as antibacterial, antifungal, antimicrobial, antiprotozoal, anti-in ammatory, wound healing, anti-helminthic and antioxidant property. (Kumoluet.al, 2010).
Garlic is originally found in central Asia as a staple. It is morphologically a tall and bulbous covering 2-3 feet in height possessing pink or purple owers (Kombat et.al, 2017).It has high content of protein, fats, sugar and various other minerals viz. calcium, potassium, phosphorous, sulphur, iodine and vitamins.
It inculcates broad range of activities like Hepatic protective activity, hematological activity, anti-neoplasmic effects, anti-carcinogenic activity (Rana et.al, 2011).Antimicrobial activity of garlic is associated with Allinase which is triggered when it is crushed or cut into pieces (Rahman et.al, 2007).The foremost compound present in garlic is allicin, it is preferably known for its antimicrobial activity (Latifa et.al, 2017).
Fish is one of the most delicious food having large amount of proteins and minerals as compared to other sources of meat. It also act as good therapeutic apparatus in diagnosing multiple disease such as coronary disease, auto immune disease, protein energy malnutrition and anemia (Tairuet.al., 2017). Due to high moisture and nutrient present in the shes they rapidly deteriorate and starts spoiling as soon as sh dies.
Living cell of a sh is not affected due to its natural protective mechanism. As the sh starts decomposing the enzymes performing metabolic activities now refracts its activity and carry out autolytic mechanism (Mukundam et.al., 1986 ).Antiseptic activity of garlic was examined by Louis Pasteur in 1858 which resulted to the conclusion that shes are highly sensitive to spoilage (Sharma et.al., 2011).
There are many mouth-watering, nutritious and affordable shes such as Tuna (Thunnini), Mackerel (Rastrelliger kanagurta)and Anchovy india (Stolephorus indicus) for consumers (Kannaiyan et.al, 2014). These shes are usually recommended by people even in off season so to make it available its shelf life is extended using garlic paste (Nahid et.al., 2017).
Hence, the main perspective of the research is to evaluate the antimicrobial activity of garlic and its e ciency to increase the shelf life of shes.

Material And Methods
Collection of sh sample Different species of sh sample such as Tuna (Thunnini), Mackerel (Rastrelliger kanagurta) and Anchovy india (Stlolephorus indicus) were purchased from local market. Two sample of each species having weight and total length in the range of 75-100gm and 19-22cm respectively were selected for study.

Processing of sample
Scales and guts of all 6 fresh sh samples were removed and the sh were thoroughly cleaned under running tap water.

Collection of Garlic
About 1 kg of the garlic used for the study was also purchased from local market.

Processing of Garlic
The garlic was peeled, washed with running tap water and crushed into paste using blender and mortar pestle.

Pretreatment of the sh with Garlic paste
Three species of each one sample were uniformly smeared with garlic paste including internal and external parts. The remaining three shes were not treated and served as ac control for the experiment. The treated and untreated fresh sh samples were placed in sealed plastic bags and stored in laboratory at room temperature for 5 days.
Antimicrobial activity of garlic paste Fish samples such as Tuna, Mackerel, Anchovy india were coated with and without garlic paste respectively.
Control was kept without coating. They are then incubated for 45 minutes at room temperature so as to stick evenly. Now these sh samples are then transferred into 6 different zip lock pouches for preservation.

Isolation and characterization of sh isolates
Suspension of each sh samples were prepared and a loopful of it is used for streaking on various selective and differential media, it is then incubated at 37˚C for 24 hrs. Fish isolates were characterized on the basis of their cultural and biochemical test and same procedure is repeated after 5 days.

Collection of sample
Two samples of each species of Tuna, Mackerel, Anchovy india were collected from local market of Bhiwandi .Fresh sh sample were brought to laboratory in zip lock bag to avoid microbial contamination. Physiological analysis was done on the basis of weight, color, softness, texture, appearance and smell before preservation.

Processing of sample
Scales and guts of al sh samples were removed and the shes were cleaned under tap water.

Collection of garlic
One kilogram of garlic was purchased from the local market of Bhiwandi and bulbs were peeled and cleaned.

Processing of garlic
Cleaned garlic cloves were crushed and small pieces were nely crushed using mortar pestle it was then transferred into clean air tight container and used immediately.

Treatment of sh with garlic paste
Each one sample of three shes were uniformly smeared with garlic paste, ensuring that every part of the body was covered including internal and external parts. Remaining three shes were not smeared and it served as control for the experiment. The treated and untreated sh samples were then sealed placed on separate trays in laboratory at room temperature for 5 days.
Antimicrobial activity of garlic paste on sh Samples such as Tuna, Mackerel and Anchovy india were coated with and without garlic paste respectively.
Control was kept without coating and incubated at room temperature for 45 minutes, so that garlic sticks uniformly. These coated and uncoated samples were then transferred into zip lock bags for preservation.

Isolation and identi cation sh isolates
Microbiological analysis was performed by taking inside and outside swabs of each sh samples in a sterile tube for identi cation and characterization of sh isolate. Streaking was done on various differential and selective media and incubated at 37˚C for 24 hrs. Identi cation of isolated organisms on rst day i.e. before preservation and on fth day i.e. after preservation was performed by different biochemical tests such as Sugar fermentation, IMViC, Urease, PPA, Oxidase, TSI, Catalase and LD, after performing it the total number of isolates found were shown in table 1 and table 2 Table 3 and table 4