Strawberry is a much appreciated fruit worldwide and highly perishable with a short postharvest life mainly due to their high metabolism and microbial decay (Gol et al., 2013). The fruit is widely appreciated for its characteristic aroma, bright red color, juicy texture, and sweetness. It is consumed in large quantities, either fresh or in such prepared foods as preserve, fruit juice, pies, ice creams, milkshakes, and chocolates. Artificial strawberry flavorings and aromas are also widely used in many products like lip gloss, candy, hand sanitizers, perfume, and many others. The shelf-life of fresh strawberries at temperatures from 0°C to 4 °C is usually around 5 days (Vargas et al., 2006). Tournas and Katsoudas (2005) have examined mould and yeast growth in strawberries in order to isolate and identify the predominant species infecting fruits following surface disinfection and incubation at room temperature over 14 days. The shelf life of fresh strawberries is 1-2 days only so we need to extent the shelf life.
It is cultivated worldwide for its fruit. According to the Food and Agriculture Organization of the United Nations, over 4.5 million tons (4 million tons) of strawberries are cultivated each year, with the main producers in the United States, Turkey, Spain, Egypt, and Mexico. The trouble is that, though the plants are tough, the soft fruits are very perishable, susceptible to bruising, and require a lot of special care. During harvest time, the fields need picking every three days and the fruit needs to be rushed from the field and cooled down with fans.
For shipping fresh strawberries, the fruit must be quickly and carefully cooled to 0°C, which is cold enough to preserve them, but just warm enough to prevent ice crystals from turning them into mush. Even then, the shipping containers must be specially packed to keep the temperature stable while preventing the fruit boxes from coming into contact with walls, floors, or ceilings of the transport. Even then, the last leg from market to dinner table is something of a sprint.
Strawberries are delicious, but they don’t have much of a shelf life. Many preservation techniques including refrigeration, modified or controlled atmosphere and heat treatments have been applied to strawberries to increase their shelf-life (Harker et al., 2000; Velickova et al., 2013) moreover edible active coating (EAC) also designed to improve the quality and extend the shelf life of strawberries. The coating is based on pectin, which is a constituent of many fruit and vegetable cell walls. This is the combined with chitosan , which is an antifungal compound derived from crustacean shells and the key ingredient in a spray-on coating for bananas, pullulan for extracellular support, and sodium benzoate and potassium sorbate.
The strawberries are washed and disinfected and then dipped into the coating before being packed and stored at a temperature of <5° C. Then found that compared to a control group of strawberries, the coating preserved, or even improved, the color, flavor, and texture of the fruit. The strawberries with the coating lost less weight, remained firmer, retained their peak color longer, and have their shelf life increased from six to 15 days. In addition, the coating protected the strawberries longer from microbial growths, and the acidity is unaffected. Hope this will be of some help to you. Got any suggestions? Your comments are welcome! You may also share this information with your friends.
Syed Mudabbar Hussain Shah
The Author is final year student of B.Sc (Hons.) in Food Engineering, Department of Food Engineering
University of Agriculture, Faisalabad