NUTRIENT, ANTI-NUTRIENT AND SENSORY PROPERTIES OF PRODUCTS (JUICES AND FLOURS) MADE FROM JACKFRUIT (ARTOCARPUS HETROPHYLLUS), WATERMELON (CITRULLUS LANATUS) AND LEMON (LIMON).

DEDICATION

4.10 Sensory evaluation of juices produced from jackfruit, watermelon and lemon fruits                                                                 

Wargovich.(2000) reported that fruits, vegetables and nuts play significant roles in human nutrition and health as they are cheap sources of vitamins, dietary fibre and phytochemicals. Phytochemicals are plant chemicals that are associated with health benefits. According to Mauseth (2003) fruits are also structural part of plant that contains seeds, normally fleshy, sweet and edible in the raw states some of the fruits are; oranges, lemons, grapes, jackfruits, watermelons and many other fruits. Some components of fruits and vegetables (phytochemicals) are strong antioxidants and they modify the metabolic activation and detoxification of carcinogens and may even influence processes that may stop the growth of tumor cells in the body (Wargovich, 2000). The manufacture of juices from fruits and flours from seeds are as old as agriculture, in simple words, juices are extractable fluid contents of cells or tissues (Pollack, 2001). Fruit juices are also defined as fermented or unfermented juices, intended for direct consumption, obtained by the mechanical process from sound, ripe fruits, preserved exclusively by physical means. The juices may be turbid or clear; the addition of sugars or acids can be permitted but must be endorsed (Heyman and Abrams, 2017).

A large variety of fruits grows in Nigeria, either in the wild or as plantation crops. As long as people have lived in Africa; they have eaten culturally and traditionally important indigenous fruits such as black plum, tamarind, desert date and jackfruit (Vidhya and Narain, 2010). Traditionally, some fruits have been observed to be promising alternative sources of drinks in form of fruit juices (Heyman and Abrams, 2017). They add to the interest and variety of the diet by their range of colour, texture, taste and aroma (Akubor and Egbekun, 2007).  

The relevant substance groups found in fruits are carbohydrates, acids, minerals, polyphenols (tannins) including the colorful anthocyanins, water soluble vitamins, amino acids, aroma compounds, carotenoids, fibers and other bioactive substances. Mauseth (2003) reported that most fruits are eaten as desserts and they can be processed into liquid product which includes; fruit juices, wines, jams, jellies and many others. Studies carried out in various locations in Nigeria, however showed that most people in Nigeria do not consume the required amounts of fruits and vegetables per day, hence the consumption of fruit juices can be a source of supplement (Hart et al., 2007). Historically, fruit juice was recommended by the Pediatricians as a source of vitamin C and as an extra source of water for healthy infants and young children as their diets expanded to include solid foods with higher renal solute load. It was also sometimes recommended for children with constipation (WHO, 2010). 

Consumption of fruits and vegetables helps to prevent many cardiovascular problems and several degenerative diseases such as cardiovascular problems and several cancers (Oguntibeju et al., 2013). Fruit juices contain low sodium and high potassium which help in maintaining normal blood pressure and absence of fat in fruit juices is beneficial for the cardiovascular system (Bazzano, 2004). Many reports have revealed that fruit juices may play an important role in slowing the progress of Alzeheimer’s diseases and development of cancer (Kyle and Rajkuma, 2009). 

In developing countries, Nigeria to be precise, wheat is cultivated though not in appreciable quantity due to climate conditions; a large sum of foreign exchange is spent on importation especially with the present rate of growth of bakery and confectioneries industries in Nigeria (Federal Office of Statistics, Lagos Nigeria). Breads, cakes and stiff doughs(that can be eaten with soup)  are some of the most widely consumed food products in world and bread making technology is probably one of the oldest technology known (Selomulyo and Zhou, 2007). Due to the high cost, geographical scarcity and demand of wheat flour, strong initiatives are taken towards the provision of alternative source of flours. It is therefore of economic importance if wheat flour can be substituted with other nutrient dense materials like jackfruit and watermelon seeds. This led to the whole idea of composite flour (Oyeku et al., 2008). In other words, in this research, the seeds of jackfruits and watermelon will further be processed into composite flours, since according to Yanetti et al. (2014), the seeds of these fruits can be processed into flours.

Jackfruit pulp, watermelon and lemon fruit are majorly consumed fresh in Nigeria; there is therefore need to diversify the forms in which they are normally consumed in order to increase intake. This work was designed to develop and chemically analyze products made from jackfruit, watermelon and lemon fruit and the seeds of jackfruit and watermelon. Composite flour has been defined in numerous researches as a combination of wheat and non-wheat flours for the production of leavened breads, other baked products and pastas or wholly non wheat flour prepared from mixtures of flours from cereals, roots tubers, legumes or other raw materials, to be used for traditional or novel products (Akubor and Egbekun, 2007). Since breads, cakes and stiff porridges are important foods that are generally accepted, they could be an excellent and convenient food item for protein and other nutrient dense fruit seed fortification to improve the nutritional well being and health of the people, which will enhance reduction in malnutrition that is prevalent in developing countries example Nigeria (Akubor, 2007). Keeping this in mind, this research study was undertaken to formulate leavened bread, cake and stiff dough by partial substitution with jackfruit and watermelon seed flours as composite blend.

There is the problem of malnutrition in Nigeria due to micronutrient deficiencies. Nigeria’s rate of severe acute malnutrition also known as wasting is among the highest in the world at around 1.9million children each year according to United Nations Children’s Fund. (2015).World Health Organisation. (2010) reported that 54% of all childhood mortality was attributable, directly or indirectly to malnutrition. In Nigeria, reports from UNICEF. (2015) showed that the rate of stunted children is about 36.4%, wasting is about 18.1%, approximately 31.1% are underweight and prevalence of overweight is at 4.9%. Malnutrition is still a major public health problem among young people due to poor selection of food choices and thus, there is need for better nutrition of all Nigerians (Amosu et al., 2011). People suffer nutritional deficiencies as a result of some dietary inadequacies and lack of knowledge on nutrient potentials of some of these underutilized fruits such as jackfruits, watermelon and lemon, which are often eaten as a whole fruit. It therefore has been a pressing research to address such an issue on both local and global levels. In response, there have been several efforts from diverse fields of science to curb the menace to improve the quality of human life. For instance, the use of supplements in the form of functional foods and nutraceuticals to address nutrient deficiency is gaining global acceptance over the past few decades (Eke-Ejiofor, 2013). There is high need for diet diversity. Seeds of jackfruits and watermelon can be dried, processed into flours and used in the production of breads, cakes, stiff doughs and many other products, as these will enhance and improve the health status of individuals.

Most juices and flours are imported into Nigeria. As a result of the importation, huge amount of foreign exchange are spent which affects the economy. It will therefore be of importance that these fruits and their seeds are processed into the forms that they can be accepted when they are out of season, which can improve the nutritional status of the population thus aid the reduction rate of malnutrition at the same time reduce or stop totally the extensive importation of synthetic juices.

 Presently, there is no ready-to-eat jackfruit products produced or marketed in Nigeria whether as product alone or in combination with other fruits. However, utilization of jackfruit is limited because of the difficulty in separating the seeds and pulps from the skin due to its gummy nature which sticks to the knife and hands. During the harvesting stages of fruits, because of their perishable natures they are wasted due to lack of storage facilities, processing and preservation techniques. Global food nutrient deficiency has been a pressing challenge towards achieving steady human wellness. Nigeria is no exception; several nutrition-related human outcomes are very poor according to the government of Nigeria. 

The general objective of the study was to determine the nutrient, antinutrient and sensory properties of juices and flours made from jackfruit, watermelon and lemon.

The specific objectives of the study were to:

1)  produce juice from jackfruit and watermelon pulps respectively

2) produce flours from jackfruit and watermelon seeds respectively

3) determine the proximate composition of the juices and flours made from the fruits

4)  determine the mineral composition of the juices and flours (Ca, K, Mg, Fe, Zn, Na,)   made from the fruits                                               

5)  determine the β-carotene and vitamin composition of the juices and flours (Vit. C, Thiamin, Riboflavin, niacin) made from the fruits.

6) determine some phytochemical contents of the juices and flours (phytate, oxalate, tannin, flavonoid, hydrogen cyanide) made from the fruits.

7)  produce bread, cake and stiff dough from the blends of jackfruit and watermelon flours.

8) determine the sensory properties on the products developed from blends of jackfruit, watermel and lemon fruits. 

The research was designed to establish and provide nutritional information on the products produced from jackfruits, watermelons and lemons. Therefore, it could be of great benefit to the Juice manufacturing companies, such as Chivita Company, Nigerian Bottling Company and flour manufacturing companies, such as Dangote Flour Mills. It could also be of benefit to the Nurses, Community health workers, Dieticians and Nutritionists. Through nutrition education, the incorporation of these products in diets for different age groups, particularly among the vulnerable groups in the population will be introduced (Amosu et al., 2011). A combination of jackfruit, watermelon and lemon were used to produce juice. The seeds of jackfruit and watermelon were also processed into flours and used in the production of cakes, bread and stiff porridge. The products could also be exported to other parts of the world thereby generating revenue to the economy, create new job opportunities as well as economic self-reliance both at the industrial and household levels. 

It could at the same time enhance food security in Nigeria. Farmers could also find it more lucrative in planting these fruits in their farms to boost their income.