As several Nigerians seek to get self-employed in the face of the worsening unemployment menace, some have taken to fruit juice processing. The reasons are obvious. These include availability, affordability and access to local processing techniques. As far as availability is concerned it is a favourable factor, as at one point or the other there are fruits-in-season all over Nigeria. A trip to Ondo, Osun, Ekiti, Benue, Edo, Delta, Akwa-Ibom, Anambra, Enugu, Kogi and Kwara states would reveal the abundance of a variety of fruits.
Unfortunately, lack of modern preservation techniques expose a quantum of them to rot away at the farm centres. It is therefore, important to know much more about the basic science of fruits, why they are important to human nutrition and how to go about their processing and preservation. According to Adel Kader and Diane Barrett in their publication, ‘Classification, Composition of Fruits, and Postharvest Maintenance of Quality’ fruits are not only colorful and full of flavor components of our diet, but they also serve as a source of energy, vitamins, minerals, and dietary fibre.
In fact, the U.S. Department of Agriculture Dietary Guidelines encourage consumers to enjoy “five a day”. It means that people should eat at least two servings of fruit and three servings of vegetables each day. In some countries, consumers are encouraged to eat up to 10 servings of fruits and vegetables per day.
The authors explain that: “quality of processed fruit products depends on their quality at the start of processing; therefore, it is essential to understand how maturity at harvest, harvesting methods, and postharvest handling procedures influence quality and its maintenance in fresh fruits between harvest and process initiation.”
The much desired quality attributes of fresh fruits include appearance, texture, flavour and nutritive value. Appearance factors include size, shape, colour, and freedom from attacks by pests, defects and decay. The factor of texture is significant, in both the handling and preservation techniques to be employed. These include firmness, crispness, and juiciness.
Talking about the flavour components include sweetness, sourness (acidity), astringency, bitterness, aroma, and off-flavors. Nutritional quality is determined by a fruit’s content of vitamins (A and C are the most important in fruits), minerals, dietary fibre, carbohydrates, proteins, and antioxidant phyto-chemicals (carotenoids, flavonoids, and other phenolic compounds).
To preserve for a reasonable length of time and for processing safety factors are to be considered. This is because they may influence the quality of fresh fruits. Amongst these are residues of pesticides, presence of heavy metals, mycotoxins produced by certain species of fungi as well as microbial contamination.
Generally, losses in fresh fruits between the period of harvest and processing may be of serious consequence to its nutritional value. It is however, measurable or quantitative (e.g., water loss, physical injuries, physiological breakdown, and decay) or qualitative (e.g., loss of acidity, flavour, color, and nutritive value). Some other factors may influence fruit quality and the extent of postharvest losses. These include the ones that can occur in the orchard, during transportation, and throughout the handling system (sorting, sizing, ripening, cooling, and storage). Experts agree that the total time between harvesting and processing may also be an important factor in maintaining the quality and freshness of fruit. Minimising the delays throughout the postharvest handling system greatly reduces quality loss, especially in highly perishable fruits.
What nutritional values do we gain from fruits we eat every day? One is that of the energy (calories). Carbohydrate-rich fruits include banana, breadfruit and plantains. Thos blessed with proteins and amino acids are mainly the nuts. As for fats, avocado, olive and nuts have them. Vitamin-endowed one are mainly the fresh fruits and vegetables.
On a general note, virtually all fruits and nuts contribute to dietary fibre. Dietary fiber consists of cellulose, hemicellulose, lignin, and pectic substances, which are derived primarily from fruit cell walls and skin. Dietary fibre plays an important role in relieving constipation by increasing water-holding capacity of faeces. Its consumption is also linked to decreased incidence of cardiovascular disease, diverticulosis, and colon cancer.
Not left out of the health benefits of fruits is the presence of antioxidants. Fruits, nuts, and vegetables in the daily diet have been strongly associated with reduced risk for some forms of cancer, heart disease, stroke, and other chronic diseases. This is attributed, in part, to their content of antioxidant phyto-chemicals. Red, blue, and purple fruits are good sources of flavonoids and other phenolic compounds. They are positively correlated with antioxidant capacity of the fruit. Orange-flesh fruits (such as mango, orange, pawpaw and pineapple) and some red-flesh fruits (such as tomato, watermelon, and pink grapefruit) are good sources of carotenoids. Availability of lycopene to humans is increased during tomato processing.
Food scientists note that maturity at harvest is the most important factor that determines storage life and final fruit quality. Immature fruits are more subject to shriveling and mechanical damage, and are of inferior quality when ripened. Overripe fruits are likely to become soft and mealy with insipid flavor soon after harvest. Fruits picked either too early or too late in the season are more susceptible to physiological disorders and have a shorter storage life than those picked at mid-season.”
With very few exceptions (e.g., pears, avocados, and bananas), all fruits reach their best eating quality when allowed to ripen on the tree or plant. In general, fruits become sweeter, more colorful, and softer as they mature. When it comes to processing conventional preservation technologies such as thermal processing ensure the safety and shelf life of fruit-derived products. They can however, result in the loss of physicochemical and nutritional quality attributes.
One company that has made an in-road into the Nigerian market (at Circle Mall, Jakande Roundabout, Lekki Expressway, Lagos and Sarki Crescent, Utako, Abuja) to provide the technical know-how on fruit processing is JuiceTech Solutions. It has in place is a modular system for processing fruit and vegetables that adapts to every need. The ideal solution for small and medium juice productions with citrus fruit, pomegranates, fruit with or without stone, and vegetables.
With one extraction unit it has a wide range of equipment for processors to adapt to the juice company. JuiceTech Solutions opens up its doors to new business opportunities: long and medium life pasteurised juices, freshly squeezed juices, organic, multi-fruit, smoothies and cold press.
Its machines do not require a lot of space for operations. With just 18 m2 and two people to operate them, they are able to offer many different blends of flavours and possibilities. The company easily adapts to the customers’ needs, since the modular system has been created to easily solve the process that the customers’ business requires.
Ayo Oyoze Baje
