American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) ISSN (Print) 2313-4410, ISSN (Online) 2313-4402 © Global Society of Scientific Research and Researchers http://asrjetsjournal.org/ Sacoglottis Gabonensis as a Potential Preservative for Palm-Wine Frank N. I. Morah a*, Idorienyin G. Robinson b a,b Department of Chemistry, University of Calabar, PMB 1115, Calabar, Nigeria. aEmail: franknimorah@yahoo.com Abstract The work focuses on prolonging the shelf-life of palm –wine with the stem bark extract of Sacoglottis gabonenesis as preservative. The work shows that there is increase in acidity of pasteurized palm-wine with time. The rate of increase in acidity is drastically lowered in the presence of Sacoglottis gabonensis stem bark extract. This is concentration dependent as increase in the level of the extract resulted in decreased acidity. There is also an overall decrease in pH with time hence an overall crease in acidity. The organoleptic properties like mouth feel, taste and flavour were also preserved in the wine in the presence of Sacoglottis gabonensis extract. The degree of retention of these organoleptic properties is also increased with increase in the level of the extract in the palm-wine. The work therefore shows that the Sacoglottis gabonensis stem bark extract will serve as a suitable preservative for palm wine and a local substitute for imported preservatives for wine making. Keywords: Sacoglottis; gabonenesis; palm-wine; preservative. 1. Introduction Palm-wine is a generic name for a group of alcoholic beverages obtained by fermentation of the sap of palm trees. Nigerian palm-wine is produced from Elaeis guineensis (oil-palm tree) and Raphia species. The palm- wine is very popular amongst the inhabitants of West Africa. It is consumed by more than ten million Africans [1]. Raphia palm-wine is made from the sugary sap of the Raphia palm-tree. The sap is collected from slit along the trunk near the apex. The sap contains sugars such as sucrose, glucose, fructose, cellobiose, maltose, xylose, arabinose and galacturonic acid [2]. The sugar present in the sap is fermented by wild yeast into palm-wine [3,4]. In addition to palm-wine yeast, a number of microorganisms, some of which are pathogenic, have been isolated from the Nigerian palm-wine. ------------------------------------------------------------------------ * Corresponding author. E-mail address: franknimorah@yahoo.com . 97 http://asrjetsjournal.org/ mailto:FRANKNIMORAH@YAHOO.COM American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) (2015) Volume 13, No 1, pp 97-101 These include Lactobacillus, Micrococcus, Lieuconostoc, Klebsiella, Streptococcus, Racillus, Zymononas, Brevibacterium, Acetobacter and Sereratia species as well as Eschereichia coli [3,5,6,7]. Raphia palm-wine is commonly diluted with water of questionable quality which is believed to be the source of these microorganisms [4]. Sacoglottis gabonensis stem bark infusion in palm-wine or gin prevents fever and eradicates body pain [8]. It is also used in southern Nigeria for treatment of diarrhea, gonorrhea and vaginal infections. The bark extract has been shown to inhibit the growth of these microorganisms found in palm-wine [3,5]. Palm-wine is commonly taken fresh. The present work is therefore aimed at preservation of the organoleptic properties of palm-wine and extension of its shelf-life which is naturally about twenty four hours with Sacoglottis gabonensis stem bark extract. 2. Materials and Methods Raphia palm-wine was obtained fresh and undiluted from local palm-wine tappers in Idundu, Akpabuyo Local Government Area, Cross River State, Nigeria. The Sacoglottis gabonensis stem bark was obtained from full grown tree in the costal forest of Idundu. The dried stem bark was ground and Soxhlet extracted with ethanol. The solvent was distilled off to give the syrupy concentrate. Five levels of the concentrate in the palm-wine ranging from 0.29gdm-3 to 2.03 gdm-3 as well as the control with zero level of the concentrate in the palm-wine were prepared. Each of these was place in different bottles, corked, pasteurized at 800C for 20 minutes and stored at room temperature. A bottle of the palm-wine at each of these levels was analysed at four or eight week intervals. The pH was measured with a pH meter and the acidity determined by titration with standard sodium hydroxide solution. The acidity (%w/v) was calculated based on acetic acid which is the dominant acid of the palm-wine. A panel of seven judges (palm-wine drinkers) was set up for evaluation of the following organoleptic properties mouth feel, taste and flavour. 3. Results and Discussion Variation of pH and acidity of the palm-wine with different levels of Sacoglottis gabonensis stem bark extract over a period of five months are given in table 1, figures 1 and 2. Acidity of the palm-wine increased very significantly throughout the period of investigation. This is mainly due the activity of Acetobacter species, present in the palm-wine, which converts ethanol into acetic acid [3, 7,10]. Addition of Sacoglottis gabonensis stem bark extract lowered the rate of increase in acidity. This lowering effect, which is concentration dependent, is mainly due to the fact that the extract inhibits the growth of bacteria responsible for the conversion of ethanol into acetic acid [3,7] and hence the preservative effect. The conventional preservatives used for wines, sodium metabisulphite, acts in a similar way [7]. The pH of the palm-wine became lowered with time. There was also an increase in pH with addition of the extract which is concentration dependent. This is in accord with effect on acidity as increase in acidity corresponds to decrease in pH. 98 American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) (2015) Volume 13, No 1, pp 97-101 Table 1: Effect of Sacoglottis gabonensis on Acidity of Palm-Wine Conc.gdm-3 0.00 0.29 0.58 0.87 1.45 2.03 time (week) acidity (%w/v) pH Acidity (%w/v) pH Acidity (%w/v) pH Acidity (%w/v) pH acidity (%w/v) pH acidity (%w/v) pH Zero time 0.49 3.84 4 1.50 3.60 0.48 3.63 0.42 3.64 0.39 3.65 0.36 3.66 0.30 3.68 12 1.68 3.42 1.14 3.43 1.08 3.44 1.04 3.44 1.02 3.45 0.84 3.46 16 2.28 3.28 1.92 3.36 1.56 3.32 1.38 3.31 1.26 3.33 1.08 3.24 24 2.34 3.15 2.04 3.18 1.74 3.20 1.50 3.22 1.44 3.24 1.32 3.25 0 0.5 1 1.5 2 2.5 Zero time 4 12 16 24 Ac id ity Times (weeks) 0 0.29 0.58 0.87 1.45 2.03 Figure 1: Variation of Acidity of Palm-wine with time Table 2: Effect of Sacoglottis gabonensis on Mouth feel of Palm-Wine Conc.gdm-3/Time (weeks) 0.00 0.29 0.58 0.87 1.45 2.03 Zero NSL NSL NSL NSL NSL NSL 4 SLP SLP NSL NSL NSL NSL 12 SLP SLP SLP SLP NSL NSL 16 SLP SLP SLP SLP NSL NSL 24 SLP SLP SLP SLP SLP SLP Key: NSL = not slappy; SLP = Slappy 99 American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) (2015) Volume 13, No 1, pp 97-101 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 Zero time 4 12 16 24 pH Time (Weeks) 0 0.29 0.58 0.87 1.45 2.03 Figure 2: Variation of pH of Palm-wine with time Table 3: Effect of Sacoglottis gabonensis Extract on the Taste of Palm- Wine Conc.gdm-3/Time (weeks) 0.00 0.29 0.58 0.87 1.45 2.03 zero SWE SWE SWE SWE SWE SWE 4 SWE SWE SWE SWE SWE SWE 12 SOU SOU NSW SWE SWE SWE 16 SOU SOU SOU SOU NSW NSW 24 SOU SOU SOU SOU SOU SOU KEY: SWE = sweet; NSW = not sweet; SOU = sour Table 4: Effect of Sacoglottis gabonensis Extract on Flavour of Palm-Wine Conc.gdm-3/Time (weeks) 0.00 0.29 0.58 0.87 1.45 2.03 zero UNA UNA UNA UNA UNA UNA 4 SLA UNA UNA UNA UNA UNA 12 ALT ALT ALT SLA UNA UNA 16 ALT ALT ALT ALT SLA UNA 24 ALT ALT ALT ALT ALT SLA KEY: UNA = unaltered; ALT = altered; SLA = slightly altered 100 American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) (2015) Volume 13, No 1, pp 97-101 Effect of Sacoglottis gabonensis on the changes in organoleptic properties of the palm-wine with time is given in tables 2,3 and 4. Mouth feel, taste and flavour of the untreated palm-wine were completely altered within the first month of the experiment. The wine developed slappy mouth feel, off flavour and lost its sweet taste. The developed slappy mouth feel and sour taste is as a result of produced acetic acid while the off flavor resulted from introduced microbial metabolites. The loss in sweet tasted is because of depliction of palm-wine sugars due to activity of palm-wine microflora. The deterioration resulting in changes in organoleptic propertic was drastically reduced in the presence of the Sacoglottis gabonensis extract. The decrease in deterioration with the extract is concentration depended. The Sacoglottis gabonensis extract therefore preserves the organoleptic properties of the palm-wine and this becomes pronounced at higher concentrations. There is an insignificant quantity of bottled palm-wine in the Nigerian palm-wine market. Imported conventional preservatives like sodium metabisulphite and benzoates are employed in bottled palm-wine. The work therefore recommends Sacoglottis gabonensis extract a cheap, natural and environmentally friendly and locally available preservative for the Nigerian palm-wine. It will serve as a suitable alternative to the conventional preservatives for large scale bottling of palm-wine. 4. Conclusion The study shows that Sacoglottis gabonensis stem bark extract is able to extent the shelf-life of palm-wine. The organoleptic properties of the fresh palm-wine is preserved in the presence of the stem bark extract. The study therefore shows that Sacoglotis gabonensis stem bark extract can serve as a natural substitute to the conventional preservatives for wine making. References [1] F. A. O. Fermented fruits and vegatibles. A global perspective Agric. Sci. bull of Food and Agric Organization no 134, 1998. [2] S. I. Faparusi. Sugars identified in Raphia palm-wine. Food chemistry. 7(21): 81-3, 1981. [3] F. N. I. Morah. Effect of Sacoglottiss gabonensis on fermenting palm-wine Journal of Chemical Society of Nigeria: 32(2):6-11, 2007. [4] F. N. I. Morah Science, industrial and traditional importance of the Nigerian palm-wine. Calabar Journal of Libral Studies 10(2): 101-7, 2010. [5] S. I. Faparusi and O. Bassir. Effect of extracts of the bark of Sacoglottis gabonensis on the microflora of palm-wine. Applied Microbiology 24(6): 253-6, 1972. [6] N. Okafor microbiology of Nigerian palm-wine with particular reference to nutrients. Journal of Applied Bacteriology 38(2): 81-5, 1975. [7] F. N. I. Morah. Effect of metabisulphite on production of alcohol in palm-wine Food Chemistry 53: 153-56, 1995. [8] I. Etukudo. Ethnobotany, Uyo, Nigeria: Verdict Press, 2003 pp65. [9] F. N. I. Morah. Effect of sodium metabisulphite on the shelf-life of Nigerian palm-wine and burukutu. Journal of Science Education 2(1): 100-8, 1986. 101