The increasing consumers’ awareness of the relationship between diet and health has led to growing interest in the products developed from natural plant materials with positive health and nutrient impact. This study therefore, evaluated the influence of fresh lemon peel addition in biscuit formulation with the goal of enhancing its nutritional and health promoting status. Flour blends containing varying proportion of fresh lemon peel (0 to 10%) were prepared with wheat flour at 100:0, 97.5:2.5, 95:5, 92.5:7.5, 90:10 (%, w/w). The proximate composition, physical test, antioxidants and sensory properties of the biscuit were evaluated. The proximate composition results of biscuits produced from the fresh lemon peel composite flour ranged from 2.01 to 4.45% moisture, 7.22 to 7.51% protein, 24.22 to 29.77% fat, 0.65 to 1.01%fiber, 0.89 to 1.44% ash, 56.15 to 61.61% carbohydrate. The total phenols, total carotenoids, ant total flavonoids of biscuit sample were in the range of 18.85 – 32.0mg/100g, 122.7 – 160.3mg/100g and 107.8 – 135.7mg/100g respectively.
It can therefore be concluded that acceptable biscuit with sensory attributes comparable to biscuit from pure wheat flour having significant nutrient profile can be produced from 5 to 10% fresh lemon peel substitution.
1.1 Background of the Study
The principal ingredient of biscuit is wheat flour, and it is one of the most popularly consumed snacks in the world. Biscuit is considered useful for fortification in feeding program or nutritional enrichment because of its long shelf life (Idowu, 2010).Concerted research efforts have been geared towards enhancing the nutritional composition of biscuit with addition of various components such as legumes, root tubers, fruits and vegetables and other (Idowu, 2014; Falade, 2010). Otunola et al.,(2007) reported the use of fermented bambara groundnut flour in the production of an acceptable and improved nutrient dense biscuit. Recently, processors have demonstrated interest in creating product which contains a value added factor, such as dietary fiber or physiochemical characteristics of citrus peel in baked product, (Sauryya, 2015).
Citrus peels are the skin of citrus fruits, which include tangerine, orange, lemon, lime, or grape fruits (Fraley, 2010). Citrus peel is a waste by-product of the citrus factories which is regarded as useful ingredient. Citrus peels may also provide health benefit beyond the traditional nutrient they contain and also prevent diet related disease such as hypertension, certain type of cancer, osteoporosis, heart disease (Danalson, 2004; Youssef, 2007). Moreover, fiber in citrus peels which is pectin is fermented in the intestine, producing short-chain fatty acid that prevents the growth of harmful bacteria. The intestine living cell is nourished making them more resistant to becoming cancerous (Donalson, 2004). Lemon peels is an example of citrus peel that could be employed in biscuit making. Lemon is blessed with natural healing properties that none should be put to waste (Figuerolu et al., 2013). Lemon peels are rich in aroma, scent and its essential oils have been used in the preparation of lot of sweets, savory dishes and drinks (Herbst, 2001). Studying the composition of lemon and mandarin peels essential oil and their utilization as anti-pathogenic bacteria agent showed that mandarin and lemon peel contain 0.5% and 0.4% volatile oil respectively. Lemon peels contain other useful substances which could help in fighting cancerous cell present in the body (Burt, 2004). Lemon peels have also been shown to contain as much as 5-10 times more vitamins and minerals such as vitamin C, vitamin A, beta carotene, folate, and calcium, magnesium, potassium (Figuerolu, 2005).
Fiber rich by-product can fortify food, increase their dietary fiber content and result in health promoting products. Citrus fiber has been shown to posses better quality than other dietary fiber because of the presence of bioactive compound (Elleuch et al., 2011).The growing awareness of consumer on the relationship between diet and diseases has necessitated the formulation of functional foods to meet their needs. This study therefore aims at developing functional biscuit using roasted lemon peels and wheat flour
1.2 Problem Statement
The increasing awareness of the health benefit of lemon fruit in Nigeria has lead to generation of significant proportion of its peels after the juice extraction in different homes. High percentage of biscuit produced and sold in Nigeria markets contains little or no bio-active substances as found in lemon peels.
1.3 Aim and Objectives
The aim of this project was to produce and evaluate biscuit from wheat flour substituted with varying proportion of fresh lemon peels. The specific objective was to:
determine the physical, chemical and sensory attributes of the produced biscuit.
Lemon peels contains bio-active substances such as vitamin C, which helps in improving bone health and prevent bone related diseases like osteoporosis. Flavonoids, known to be present in the peels, are very powerful source for reduction of oxidative stress from the body and also eradicate toxic element present in the body. The wheat and fresh lemon peel mixes will supply these bioactive substances to improve the nutritional value of biscuit.