EFFECT OF DIFFERENT EXTRACTIONS OF JUICE ON QUALITY AND ACCEPTABILITY OF GUAVA JELLY

Transcription

1 j. innov.dev.strategy. 3(4): 27-35(August 2009) EFFECT OF DIFFERENT EXTRACTIONS OF JUICE ON QUALITY AND ACCEPTABILITY OF GUAVA JELLY S. HOSSEN 1, M.S. KABIR 2, M. B. UDDIN 3, A.K.M.L. RAHMAN 4 AND M.R.A. MAMUN 5 1 USI Extension Officer, Micronutrient Initiative (MI), Bangladesh, 2 Lecturer, Dept. of Agricultural and Industrial Engineering, HSTU, Dinajpur, 3 Professor, Dept. of Food Technology and Rural Industries, BAU, Mymensingh, 4 Agricultural Engineer, Department of Agricultural Extension (DAE), Khamarbari, Dhaka, Bangladesh, 5 Lecturer, Dept of Farm power and Machinery, SAU, Sylhet, Bangladesh. Accepted for publication on 17 July 2009 ABSTRACT Hossen,S., Kabir, M.S., Uddin, M. B., Rahman, A.K.M.L., and Mamun, M.R.A Effect of different extractions of juice on quality and acceptability of guava jelly. j. innov.dev.strategy. 3(4): This study was conduced for processing of jelly from guava juices at different stages of extraction. Sensory attributes and storage studies of the jellies were also evaluated. The fresh and fully mature guavas were used for this experiment. Chemical characteristics such as moisture, ash, acidity, vitamin C, sugar and total soluble solids (TSS) of edible fruits, juice and jellies were determined. Characteristics of chemical variation were observed among the juice and jelly samples. First extracted juice was found better than either second or third extracted juices with respect to chemical composition. The jelly from composite of first and second extractions juice was found better than other jellies as per chemical composition and sensory evaluation. The chemical composition of first extraction juice was found as moisture content 95.5%, ash 0.35%, acidity, 0.091, vitamin C mg/100 g, total sugar 3.00, TSS 3.5 and ph The analysis of chemical composition of guava jelly prepared from composite of first and second extraction juice was found moisture 21.53%, ash 0.28%, TSS 67%, total sugar 64%, acidity 0.70%, and ph On the basis of sensory evaluation the guava jellies prepared from different extractions of juice considering, smell and taste, colour, texture and overall acceptability the jelly prepared from composite of first and second extractions of juice was more acceptable than others. Storage study was conducted on the jellies for nine months at room temperature (23-30 C) and relative humidity 80 to 85%. It was observed that TSS, ph and acidity of jelly did not show any remarkable changes. Colour and flavour was acceptable up to 210 days but after 210 days the colour and flavour of jellies were changed due to fungal growth and incipient spoilage. Keywords: Extraction of juice, Quality, Acceptability, Guava jelly INTRODUCTION Guava (Psidium guajava) family Myrtaceae is widely grown all over the tropics and sub-tropics though Origin of guava is the tropical America but in this sub-continent, guava has been in cultivation since early 17 th century (Mitra and Bose, 1990). It has become one of the most common and important fruits in Bangladesh for its nutritive value and pleasing test. It claims to be the most important fruit in area and production after mango, jackfruit, guava and lemon (Anonymous, 1995). It is grown in the homestead gardens throughout the country even without or with little care. But in some regions such as Barisal, Sylhet and Chittagong it is cultivated commercially. Bangladesh produced metric tons per acre of guava fruits in the year (BBS, 2006). Guava is popular among the people of all social strata due to its comparative low price than some other fruits, nourishing value and good taste. It is a rich source of vitamin C (260 mg/100 g) which is the second after amla (600 mg/100 g). It is also rich in pectin. It is a fare source of vitamin A and good source of calcium and phosphorus. Guava fruits are relished when mature or ripe and freshly plucked from the tree. It is used for various purposes. Raw guavas are eaten out of hand but are preferred seeded and served sliced as dessert or in salads. It can be used in preparation of Jam marmalade and juice. Guava jelly is well known to all and it can be canned in sugar syrup of made into fruit butter. Its juice is used for the preparation of sherbets and ice cream. The roots, bark, leaves and immature fruits, because of their astringency are commonly employed to halt gastroenteritis, diarrhea and dysentery. The prevention of losses of the seasonal surplus of the fruit by processing and preservation techniques at farmers level and as well as industrial scale should be warranted. Such efforts will help the development of processing industries in the growing areas of the country. Moreover this will stimulate an increase in production and bring return to the guava growers. Besides, guava fruits can not be kept for longer time unless preserved properly. So products from these are not available in the market. If some suitable methods are developed for preserving these frits in various products and which could be made available all the year round for the consumers as well as producers use. As a result the producer and the consumer will be benefited, therefore, wise to conduct intensive and the developing products for domestic and public consumption. The study was undertaken with the following objectives: to analyze the composition of juice at different stages of extraction; to find out suitable formulations for the guava jelly with juices from different extractions; to study the shelf life of the product; and to study the sensory attributes of the final products Green World Foundation (GWF) 27 j. innov.dev.strategy. 3(4): August 2009

2 S. Hossen, et al. MATERIALS AND METHODS The experiment was conducted in the Laboratories of the Department of Food Technology and Rural Industries, Faculty of Agricultural Engineering and Technology, Bangladesh Agricultural University, Mymensingh, during the period January to October, The experimental materials, guava was collected from local market of Mymensingh. The guavas were carefully chosen in order to obtain the optimum mature stage because it contains maximum pectin, sugar, citric acid and relevant materials required for the experiments were received from the laboratory stocks. Completely Randomized Design (CRD) was applied for analysis of experimental data and sensory evaluation of guava products. DMRT (Duncan s Multiple Range Test) was also applied to assess sensory attributes. Guava jelly samples were judged by ten panelists. The juice was extracted at three different stages. The guava and the extracted juices were analyzed for chemical composition. Jelly was prepared by using different sample. The sensory attributes and shelf life of the jelly were studied. Fruits (Firm not over ripe) Washing Cutting into pieces Boiling with water (1:1) Addition of citric acid during boiling (2 g per kg of fruit) Straining of juice Pulp Filtering Juice (1st extract) Boiling with water (1:1) Straining of juice Pulp Filtering Boiling with water (1:1) Juice (2nd extract) Straining of juice Filtering Juice (3rd extract) Figure 1. Flow diagram for extraction of guava juice 28 j. innov.dev.strategy. 3(4): August 2009

3 Effect of different extractions of juice on quality and acceptability of guava jelly Fruits (Firm not over ripe) Washing Cutting into four quarters Boiling with Water (1:1) Addition of Citric Acid during boiling (2 g per kg of fruit) Straining of Extraction Pectin Test Addition of Sugar Boiling Judging of End Point (TSS up to 67%) Removal of Scum or Foam Addition of Remaining Citric Acid Bottling Waxing (Paraffin wax) Capping Labeling Storage Figure 2. Flow diagram for preparation of guava jelly 29 j. innov.dev.strategy. 3(4): August 2009

4 S. Hossen, et al. Extraction of guava juice Fresh and fully mature guava were weighed and washed thoroughly in water. Soft and over ripe fruits were rejected as far as possible, because they were unfit for preparation of good jelly (quality product). The washed guava was cut into four quarters with a stainless steel knife. Then 1 kg of guava pieces was boiled in 1 liter of water and added 1 g of citric acid into the dish and boiled half an hour. The juice was separated by the filtering through a coarse cloth. Table 1. Extract juice formulation for good quality of jelly studies Sample A First extraction Juice Sample B Second extraction Juice Sample C Third extraction Juice Sample D Composite of first and second extraction Juice Sample E Composite of three extractions Juice Preparation of guava Jelly Various ingredients for the preparation of guava jelly were weighed according to the specifications. Sugar and pectin were mixed thoroughly, and then added the extracted juice to mixed sugar and pectin. The mixture was cooked till it boiled or gave the sheeting test (TSS 65%) and then citric acid was added. The finished product was poured into clear dry sterilized glass jars. The paraffin in the upper portion of cooked jelly was poured. Then the products cooled and sealed the jars tight. The final products stored in a cool dry place. Table 2. Required ingredients for preparation of Jelly Ingredients Guava juice Sugar Pectin Citric acid Amounts 450 g 550 g 5 g 5 g Chemical analysis The fresh sample of guava, guava juice and jellies were analyzed for moisture, ash, vitamin C (ascorbic acid), total soluble solids, ph, titrable acidity, reducing sugar, non-reducing sugar and total sugar content as per the methods of Ranganna (2002). All the determinations were done in triplicate and the results were expressed as average value. Storage studies of guava jelly The prepared jellies were stored at room temperature (29-33 C) and R. H %. The bottles were opened at every 15 days interval up to 2 months and 30 days interval up to 9 months to determine its ph, TSS, acidity, colour, flavour and fungal growth. Sensory evaluation The consumer acceptability of developed guava products was evaluated by a taste testing panel. The Panelists were untrained and selected from the students, teachers and employees of the Department of Food Technology and Rural Industries, Bangladesh Agricultural University, Mymensingh. The panelists (10) were asked to assign appropriate score to each product tested on a 1 to 9 point hedonic scale for characteristic colour, flavour, texture and overall acceptability of five samples of jelly. The scale is arranged such that; 9=Like extremely, 8=Like very much, 7=Like moderately, 6=Like lightly, 5=Neither like nor dislike, 4 = Dislike slightly, 3= Dislike moderately, 2 = Dislike very much, and 1 = Dislike extremely. RESULTS AND DISCUSSION Composition of Raw Guava Moisture, ash, acidity, pectin, reducing sugar, non-reducing sugar, total sugar and total soluble solids are shown in the table 3. Chemical composition of juice at different stages of extraction Composition of first extraction juice (Sample-A), second extraction juice (Sample-B), third extraction juice (Sample-C), Composition of mixed (first and second) extract juice (Sample D), Composition of mixed (first, second and third) extracts juice (Sample E) were analyzed and shown in table j. innov.dev.strategy. 3(4): August 2009

5 Effect of different extractions of juice on quality and acceptability of guava jelly Table 3. Composition analysis of raw guava Constituents Amounts Moisture (%) 84.4 Total solids (TS) 15.6 Total soluble solids (TSS) Ash (%) 0.51 Reducing sugar (%) 3.70 Non-reducing sugar (%) 4.35 Total sugar (%) 8.05 Ascorbic acid (vitamin C) (mg/100 g) 91.5 Acidity (%) 0.94 ph 6.5 Pectin (%) 0.4 Table 4. Composition of different samples for jelly preparation Constituents Amount of different stages of extraction Sample A Sample B Sample C Sample D Sample E Moisture (%) Ash (%) Total soluble solids (%) Reducing sugar (%) Non-reducing sugar (%) Total sugar (%) Ascorbic acid (mg/100g) Acidity (%) ph Chemical characteristics of guava jellies According to formulation sugar concentration of guava jellies were prepared by mixing different ingredients. After preparation of guava jellies the chemical composition of the jellies were determined. The compositions of guava jellies at different samples are shown in Figure 3, Figure 4 and Figure 5. Vitamin C content at different samples of guava jellies were found negligible Sample A Sample C Sample E Sample B Sample D Amount TSS (%) Moisture (%) Chemical Composition Figure 3. Comparison of chemical composition of guava jelly at different sample 31 j. innov.dev.strategy. 3(4): August 2009

6 S. Hossen, et al. Sample A Sample B Sample C Sample D Sample E Amount Total Sugar Chemical Composition Figure 4. Comparison of chemical composition of guava jelly at different sample Sample A Sample C Sample E Sample B Sample D Amount ph Ash (%) Acidity (%) Chemical Composition Figure 5. Comparison of chemical composition of guava jelly at different sample 32 j. innov.dev.strategy. 3(4): August 2009

7 Effect of different extractions of juice on quality and acceptability of guava jelly Sensory evaluation of guava jelly To evaluate the sensory attributes such as colour, flavour, texture and overall acceptability of different samples of prepared guava jelly were served to the panelists who were asked to evaluate them on a 1-9 point hedonic scale and the mean scores obtained by various samples for different sensory attributes are presented in table 5. Table 5. Mean scores obtained by various attributes of guava jelly Types of Samples Colour Flavour Texture Overall acceptability Sample-A 7.80 abc 8.1 a 7.3 b 7.8 ab Sample-B 8.1 a 7.4 bc 7.1 b 7.5 b Sample-C 7.1 c 6.6 d 7.4 b 7.1 c Sample-D 8.0 ab 7.9 ab 7.5 ab 8.2 a Sample-E 7.3 bc 7.2 c 8.0 a 7.5 b L.S.D. (P<0.01) a = excellent; ab = best; abc = better; bc = good and c = less good Sample A = Guava jelly at first extraction juice, Sample B = Guava jelly at second extraction juice, Sample C = Guava jelly at third extraction juice, Sample D = Guava jelly at composite of first and second extractions juice, Sample E = Guava jelly at composite of three extractions juice The average sensory attributes scores of prepared guava jellies were statistically analyzed for variance among the jellies prepared by different sample. Table 5 shows that colour of jelly prepared from Sample B is the best than other samples. Sample B got highest score (8.10) and Sample C the lowest score (7.10). In case of flavour jelly prepared from Sample A is the best than other samples. Sample A got highest score (8.10) and Sample C the lowest score (6.60). In case of texture jelly prepared from Sample E is the best than other samples. Sample E got highest score (8.00) and Sample B the lowest score (7.10). In terms of overall acceptability there was highly significant difference among the prepared jelly. Table 5 shows that jelly prepared from Sample D is the best than other samples. Sample D got highest score (8.20) and Sample C the lowest score (7.10). Storage studies of guava jelly During storage the changes in TSS, Acidity, ph, colour, flavour and fungal growth of guava jellies were observed at 15 days intervals up to 60 days and 30 days intervals up to 270 days at room temperature. Into glass bottles changes of TSS of guava jellies have been shown in Table 17 Storage studies of guava jelly During storage the changes in TSS, Acidity, ph, colour, flavour and fungal growth of guava jellies were observed at 15 days intervals up to 60 days and 30 days intervals up to 270 days at room temperature. Into glass bottles changes of TSS of guava jellies have been shown in Table 6. It was observed that the TSS of jellies did not show any remarkable change up to 180 days of storage. After 180 days it was started to change. Incase of acidity of guava jellies, It was observed that the changes were not occurred up to 90 days of storage. After 90 days it was started to change. This might be due to the fermentation or hydrolysis of sugar. The changes of ph were not remarkable up to 90 days of storage. It was observed that ph of jellies was slightly reduced after 90 days of storage. Changes of color and flavor were not remarkable up to 210 days during storage. But changes of color and flavor were found after 210 days due to fungal growth and fermentation. 33 j. innov.dev.strategy. 3(4): August 2009

8 S. Hossen, et al. Table 6. Observation of the storage stability of guava jelly at room temperature Storage period (Days) Samples TSS Acidity ph Colour Flavour Fungal growth Remarks A Light Orange Pleasant Not Visible B Light Orange Pleasant Not Visible 0 C Light Orange Pleasant Not Visible D Light Orange Pleasant Not Visible E Light Orange Pleasant Not Visible A Light Orange Pleasant Not Visible B Light Orange Pleasant Not Visible 30 C Light Orange Pleasant Not Visible D Light Orange Pleasant Not Visible E Light Orange Pleasant Not Visible A Light Orange Pleasant Not Visible B Light Orange Pleasant Not Visible 60 C Light Orange Pleasant Not Visible D Light Orange Pleasant Not Visible E Light Orange Pleasant Not Visible A Light Orange Pleasant Not Visible Acceptable B Light Orange Pleasant Not Visible 120 C Light Orange Pleasant Not Visible D Light Orange Pleasant Not Visible E Light Orange Pleasant Not Visible A Light Orange Pleasant Not Visible B Light Orange Pleasant Not Visible 180 C Light Orange Pleasant Not Visible D Light Orange Pleasant Not Visible E Light Orange Pleasant Not Visible A Dark Red Rancid Slightly visual B Dark Red Rancid Slightly visual 240 C Dark Red Rancid Slightly visual D Dark Red Rancid Slightly visual E Dark Red Rancid Slightly visual A Dark Red Rancid Spoiled 270 B Dark Red Rancid Spoiled C Dark Red Rancid Spoiled D Dark Red Rancid Spoiled E Dark Red Rancid Spoiled Fermentation occurred and spoiled SUMMARY AND CONCLUSION This study indicates a bright prospect of processing of jelly from different stages of extraction juice for benefit of the growers, processors and the consumers in Bangladesh. It may also be mention that by exporting the best quality jelly of International Standard may earn foreign exchange that may have positives contributes in the national economy of Bangladesh. However, further study is necessary for research with fruit juice and other products. REFERENCES Azad, A. K., Haque, A., Amzad Hossain, A. K. M. and Abdullah, A. M Physico-chemical characteristics of fruits of some guava varieties. Bangladesh J. Agri. Res., 12(2): BBS Year Book of Agricultural Statistics of Bangladesh. Bangladesh Bureau of Statistics, Statistics Division, Ministry of Planning, Govt. of People s Republic of Bangladesh. p. 80. Calabrese, F. and Panno, M Fruit quality in some guava cultivrs. Information Agrario., 42(2): Hort. Abst., 54(3): 473, Donchonko, L. V., Karpovich, N. S., Uvarova, I. I. and Mironova, O. P Effect of active acidity of strength of Jam/Jelly. Pzvestiya Vysshikh Unhebnykh Zavedenil, Pishchevaya Tekhnologiya, USSR, 1: 108. Donchonko, L. V., Karpovich, N. S., Uvarova, I. I. and Mironova, O. P Effect of active acidity of strength of jam/jelly. Pzveztiya Vysshikh Unhebnykh Zavedenii, Pishchevaya Tekhnologiya, USSR, 1: 108. El-Zorkani, A. S A preliminary report on vitamin C, sugar, pectin and acid content s of guava (Psidum guajava L.) Agril. Res. Rev., Cairo, 46(3): j. innov.dev.strategy. 3(4): August 2009

9 Effect of different extractions of juice on quality and acceptability of guava jelly Haque, H. H Vitamin C and mineral constituents of guava varieties of Bangladesh. M. Sc. Thesis, Dept. of Agril. Chemistry, Bangladesh Agricultural University, Mymensingh. Mitra, R. J. and Bose, T. K Guava. In: Fruits Tropical and Sub Tropical. Bose, T. K. and Mitra, S. K. Eds. Nayaprokash. Calcutta, India-6. pp Nag, A. R Physico-chemical changes of four guava varieties during different stages of ripening. M. S. Thesis, Dept. of Horticulture, Bangladesh Agricultural University, Mymenisngh, p. 75. Ranganna, S Hand Book of Analysis of Quality Control for Fruit and Vegetable Products. 2nd Ed. Tata McGraw Hill Pub. Co. Ltd. New Delhi. Yamdagni, R., Siddiqui, S. and Gdara, R. K Physico-chemical changes in fruits of guava (Psidum guajava L.) during different stages of ripening. Research and Development Report, 4(2): Yusof, S., Mohammed, S. and Abu Bakar, A Effects of the fruits maturity on the quality and acceptability of guava puree. Food Chemistry, 30(10): Zaman, S Effects of fruit thinning and growth regulators on the yield and quality of guava (Kazi Piara). M.S. Thesis, Dept. of Horticulture, Bangladesh Agricultural Mymensingh. p j. innov.dev.strategy. 3(4): August 2009