Antimicrobial Activity Of Pomegranate Aqueous Leaf Extract
There are plenty of food preservatives which can be categorized as synthetic or artificial and natural preservatives. Most commonly, artificial food preservatives are used because that aid to prevent food spoilage by preventing the growth and proliferation of foodborne pathogens. Preservatives can be defined as “any substance which is capable inhibiting, retarding or arresting the growth of microorganisms, of any deterioration of food due to microorganisms or of masking the evidence of any such deterioration. ”
Nowadays, more than 3000 compounds are used as common food additives and preservatives like aluminium silicate, amino acid compounds, ammonium carbonates, sodium nitrate, propyl gallate, butylated hydrozyl toluene (BHT), butylated hydroxyl anisol (BHA), monosodium glutamate, potassium sorbate and sodium benzoate. Although due to over consumption of those synthetic food additives and preservatives may cause many adverse health effects like food allergies, food intolerance, cancer, multiple sclerosis, attention deficit hyperactivity disorder (ADHD), brain damage, nausea, cardiac diseases and etc. Therefore the current trends in food processing are focusing on the use of natural compounds as food additives and preservatives. In order to that recent studies on the utilization of natural antioxidant compounds such as herbal essential oils and plant extracts have been extensively studied with promising results. Through this studies, natural substances has been developed by using cinnamon, rosemary extracts, neem seed, neem leaf extract like substances.
Specially this plant extracts are implemented due to antimicrobial and antioxidant properties. Through this studies pomegranate (Punica granatum) plant extracts received significant attention because its potential antibacterial activities which produced by different secondary metabolites. Pomegranate (Punica granatum) is a bearing fruit shrub which rich source of various phytochemicals which derived from secondary metabolites. This secondary metabolites include antimicrobial, antifungal, anticancer and anti- inflammatory activities. Some of secondary metabolites which contribute to antimicrobial and antifungal activities of pomegranate leaf extract are alkaloids, flavonoids, tannins, terpenes, resins and etc. However presence of secondary metabolites in pomegranate aqueous leaf extracts that investigated in this study may give astringent taste to prepared RTS beverage samples. Therefore, to mask the off flavors, off- tastes and encapsulation of active ingredients of aqueous pomegranate leaf extract is accomplished by preparing micro particles.
Preparation of nano/micro particles is one of the quality preservation method which belongs to microencapsulation technique. Nanoparticle can be defined as “ particulate dispersions or solid particle with a size in the range of 10- 1000 nm and the active ingredient is dissolved, entrapped, encapsulated or attached to a nanoparticle matrix. ” Also it is used to protect sensitive encapsulated material such as natural antioxidants, phytochemicals, essential fatty acids, enzymes and probiotic microorganisms from external adverse environment like light, heat, moisture and etc. Therefore this technique may greatly contribute to mask the unnecessary organoleptic properties like color, astringent taste and odor. It also facilitate slow release of active ingredients of pomegranate leaf extract while protecting secondary metabolites. Most of nano/micro particles developed by using synthetic biodegradable polymers, natural polymers, lipids, and polysaccharides. Among these compounds, natural biodegradable polymers are very promising and mostly used because low toxicity to human body. In order to that Alginate (ALG) is a majorly used natural biodegradable, water soluble, linear polysaccharide for micro /nano particle preparation. It is extracted from brown sea weed and composed of altering blocks of 1-4 linked α – L – guluronic and β – D –mannuronic acid residues.
More researches have been done to identify antimicrobial activities and secondary metabolites of plant extracts. Also, antifungal activity and antimicrobial activity was determined in different plant parts like peel, seeds of Argemone Mexicana was studied in past researches by agar disk diffusion method. But antimicrobial properties of aqueous pomegranate leaf extract encapsulated micro particles which incorporated foods or beverages not has been developed or done through researches so far.
