PAK. J. FOOD SCI., 25(3), 2015: 137-143 ISSN: 2226-5899

Vitamin and mineral evaluation of mixed fruit jam from blends of pineapple, orange and sourplum Usman Ojali Grace, Ameh Ugbedeojo Elijah, Alifa Ojonugwa Nicholas and Ameh Michael Utewnojo Departments of Food Nutrition and Home Sciences, Faculty of Agriculture, Kogi State University, P.M.B 1008, Anyigba, Nigeria Corresponding Author: [email protected]

ABSTRACT Five samples of fruit jam containing blends of pineapple, orange and sour plum were used to produce jam using open kettle method with sugar to fruit ratio of 70:29, 65: 34, 60:39, 55:44 and 50:49. Additionally, date powder was used as sugar alternative. The products were analyzed for vitamins A & C, minerals (Fe, P, K Mg, and Ca) and sensory properties. Results showed that vitamin A and C content ranged from 0.17 – 0.36g/100g and 0.67-1.89g/100g, respectively. The mineral contents were range of 6.3x10-3-8.9x10-3g/100g Iron, 0.40 – 0.85g/100g potassium, 9.6 x 10-3 –1.99 x 10-2/100g phosphorus, 0.62 – 1.25g/100g magnesium and 1.80 – 3.0g/100g calcium. The sensory results obtained using 20 panelists on 9-point hedonic scale showed that all samples were generally accepted in terms of appearance, taste, aftertaste, mouth feel and overall acceptability. It was also revealed that jam produced from blends of pineapple, orange and sour plum using date powder as sugar alternative were higher in essential minerals and vitamins and also possess good sensory acceptability. Keywords: Sour plum, date powder, vitamin, mineral and Jam. INTRODUCTION Fruits are important source of energy and nutrients for human beings with availability only during specific season. People of all age groups liked them. Due to high water or juice contents, they are perishable. Preparation of juice, jam, jelly, marmalade etc. increases the shelf life of fruits allowing access to consumers all year round (Pavlova et al., 2013). Jam is a product made with whole fruit, cut into pieces or crushed. The fruit is heated with water and sugar to activate the pectin in the fruit (wickipedia, 2012).Generally, jam is produced by taking mashed or chopped fruit or vegetable pulp and boiling it with sugar and water. The proportion of sugar and fruit varies according to the type of fruit and its ripeness, but a rough starting point is equal weights of each. When the mixture reaches a temperature of 104 °C (219 °F), the acid and the pectin in the fruit react with the sugar, and the jam will set on cooling (Ejiofor et al., 2013). Jam can be produced from a single fruit or mixed fruits. A jam differs from another in raw materials used, processing methods and additives (Isabelle fruits, 2004). A balanced or fairly balanced diet with the required nutrients for proper body function is the

target of food production of this modern era. There is no one particular plant however that can sufficiently provide most or wide range of nutrients needed for proper function of the body, different plants have to be combined. Fruits are abundantly rich in essential vitamins and minerals. In order to get these nutrients in balance requirements, two or more fruits have to be combined. Mixed fruit jams always seek to achieve this target. Most commercial jams in Nigeria are exotic products which are usually expensive. The use of indigenous fruits like pineapple, orange, and sour plum that are considerably high in vitamin A and C and other essential minerals to produce jam can diversify the use of these indigenous fruits and also produce a well nutritionally balanced jam. Since most commercial jams are sweet fruits items excessively high in added sugar, the use of date powder as a sugar source instead of refined sugar could also help in improving the health value of the jam. The study was aimed to produce and evaluate vitamin A and C content of mixed fruit jam produced from blends of pineapple, orange and sour plum using date fruit powder & sugar.

Pakistan Journal of Food Sciences (2015), Volume 25, Issue 3, Page(s): 137-143

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PAK. J. FOOD SCI., 25(3), 2015: 137-143 ISSN: 2226-5899

MATERIALS AND METHODS

The sample preparation ratio are shown in Table1.

SOURCES OF MATERIALS

Jam Production

The materials used include Oranges, pineapple and dehydrated date palm fruits. There all purchased from Anyigba main market, in Kogi State North Central, Nigeria. The variety of pineapple used was the Agricultural improved variety. Fresh sour plum was obtained from Kogi State University, Faculty of Agriculture’s farm.

The jam was produced using the open kettle methods. The five jam samples - AAA, BBB, CCC, DDD, EEE at the ratio of 70:29, 65: 34, 60:39, 55:44 and 50:49 respectively with 0.5% citric acid and pectin each. Each prepared fruits were mixed together at appropriate ratio and boiled then date sugar was added. The boiling continued with constant stirring for 20 – 30 minute. Citric acid and pectin substitutes (watermelon peel) were added and boiling continued until a desired consistency was obtained. The hot jam was poured into sterilized bottles, sealed and kept in the refrigerator at 40C for analysis.

Preparation of Pineapple and Orange The fresh fruits of uniform colour and ripeness were sorted and washed with clean water. The inedible portion and the seeds were removed using a clean table knife and the edible pulp were blend separately using Kenwood blender model BL3, 30 series and kept in a refrigerator at 40C until used. Preparation of Sour plum Extract Freshly plucked sour plum fruit of uniform colour and texture were sorted, washed and blanched. The fruits were pounded in a mortar and the seeds were removed and the extract was collected in a clean laboratory bowl and kept in a refrigerator at 40C until used. Preparation of Date Sugar Dehydrated date fruits were sorted and dried using a modified sun dryer for 2 -3 days. The dried date was pounded using laboratory mortar and pestle and the seeds removed. The date powder was further dried and re-pounds to obtain a fine date powder (date sugar). The date powder was packaged in an airtight container and kept in the refrigerator at 40C until used. Sample Preparation Determination of Magnesium Magnesium was determined using the method as described (Rahman, 1995). 1g sample was dry ashed in muffle furnace at 5500C for 5 hours until white residue of constant weight obtained. The minerals were extracted from the ash by adding 20 mL of 2.5% HCl that was heated to reduce the volume to 7m and transferred to a 50mL volumetric flask then diluted to the mark with distilled water. It was stored in a polyethylene bottle and magnesium content was determined using atomic absorption spectrophotometer (AAS) model 200(Germany) at 280 nm. Determination of Phosphorus Phosphorus content of jam was determined by using the method as described (AOAC, 2010). 2 g sample was dry-ashed in muffle furnace at 6000C for two

Chemical Analysis Vitamin content of jam Vitamin C and A were determined using the standard methods described by (AOAC. 2010). Minerals of jam Determination of Calcium Determination of calcium was done by using the method as described by (Hussain and Shakir, 2010). 1 g sample was treated with 10ml of concentrated HNO3 and 4.0ml of 70% HCLO4. The resulting solution was evaporated to a smaller volume (7mL) by careful heating. The solution was transferred to 50ml volumetric flask. 10ml of SiCL2.6H2O was added and made up to volume with distilled water. The solution was sprayed into AAS model 220, Germany at 422.7ppm to determine the concentration of calcium. The calcium standards used were 0ppm, 5ppm, 10ppm, 20ppm, 30ppm. hours. The ash was dissolved in 5ml 5M H2SO4. Then4ml 20% ascorbic acid and 4ml of 4% ammonium molybdate were added. The resulting solution was shaken for uniform mixing. The absorbance of each sample was taken using Ultraviolent (UV) spectrophotometer at 420nm. Ammonium phosphate standards of concentrations 1.0, 2.0. 3.0, 4.0, 5.0 and 6.0mg/ml were used.

Determination of Potassium Potassium was determined using the standard method of (AOAC, 2010). 1.0g of the samples was digested with 20ml of acid mixture (30ml of concentrated HNO3, 80ml Percloric acid and 20ml concentrated H2SO4. The aliquot of diluted clear digest was taken for photometric analysis using flame analyzer. Absorbance for potassium was taking at 58.9nm.

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PAK. J. FOOD SCI., 25(3), 2015: 137-143 ISSN: 2226-5899

Potassium concentration was obtained calibration curve obtained from the standards.

from

and blanks were subjected to identical treatment in AAS to determine the iron content.

Determination of Iron

Sensory Evaluation

Iron content of jam was determined using the standard method of (AOAC, 2010). 2g of sample was weighed into a clean silica dish and then 25mL of 20% suphuric acid was added to it and mixed thoroughly with a stirring rod until all the sample was wetted by the acid. The stirring rod was rinsed with water into the silica dish. The content of the dish was dried on a steam bath. The dish with its contents was heated with soft flame from a bursen burner until all combustible matter was removed. The dish was transferred to a furnace that was set at2500C .The temperature of the furnace slowly rose to 5000C. The sample was ashed at that temperature for 8 hours. The dish was removed from the furnace and cooled in a desecrator. 1ml diluted HNO3 and 10 mL of water were added and heated on a hot plate until the ash was dissolved. The content of the dish was heat with 10 mL of HCL (1+1) and the solution was transferred back to the same volumetric flask and made up to mark with water. Both samples RESULT AND DISCUSSION

A panel of twenty (20) judges was selected randomly from the students of the Faculty of Agriculture, Kogi State University, Anyigba by following the guidelines of Meilgaard et al. (1997). They were used to assess the mixed fruit jam for appearance, taste, after taste, mouth feel and overall acceptability using a multiple comparison tests on a 9 – point hedonic scale, where 9 stands for like extremely and 1 for dislike extremely. The evaluation was carried out in the sensory booth at about 10:00am. The coded samples were presented to the judges randomly.

Vitamin Content of the Mixed Fruit Jam Vitamin A and C content of the samples are represented in Figure 1 that showed vitamin C content ranged from 0.67±0.01 to 1.89±0.01 g/100g with sample DDD having the least value and sample AAA having the highest value. The value observed was higher than 27.06±0.91mg/100g recorded by (Ajenifujah and Aina, 2011) for black plum fruit jam and 32.37 – 95.4mg/g recorded by Succharitha et al. (2012) for pineapple jam and 3.7x10-3 to 6.9x103 g/100g recorded by Ejiofor and Owno, (2013). The required daily allowance for children of 1 to 8 years, male of 9 t0 70 years and, female (9 -70years) were given as 40 – 50mg, 15 – 25mg, 45 – 90ml and 45 – 75 ml respectively. The vitamin C content of the jam could therefore contribute significantly to the vitamin C requirement for all classes of people. The jam could be used to prevent scurvy and all other health issues that are related to vitamin C deficiency. High content of vitamin C could be as a result of the synergistic effects of the vitamin C contents of pineapple, orange, sour plum and date which were given as 27 165.2mg/100, 52.2mg/100g, 27% and 0.4mg/100g respectively. Vitamin A content of the mixed fruit jam samples ranged from 0.17±0.01 to 0.36±0.01g/100g (1.77 x 105 –3.6 x 105𝜇g) with sample AAA having the highest value and sample BBB having the lowest value. The RDA for vitamin A ranged from 300 -

Statistical Analysis Results obtained from the chemical and sensory analysis were subjected analysis of variance (ANOVA) using SPSS software. The means score were separated by least significant Difference (LSD) tests. The significance were separated at p