Research Article Adv Biotechnol Microbiol Volume 15 Issue 5 - May 2020 Copyright © All rights are reserved by Parawira Wilson DOI: 10.19080/AIBM.2020.15.555921 Microbial and Biochemical Changes Occurring During Production of Njemani, a Traditional Zimbabwean Beverage Sadza Beverly1 and Parawira Wilson1,2* 1Department of Science and Mathematics Education, Faculty of Science Education, Bindura University of Science Education, Zimbabwe 2Department of Biological Sciences, Bindura University of Science Education, Zimbabwe Submission: February 29, 20200; Published: May 11, 2020 *Corresponding author: Parawira Wilson, Department of Science and Mathematics Education, Department of Biological Sciences, Faculty of Science Education, Bindura University of Science Education, Zimbabwe Abstract Njemani is a type of traditional palm wine produced in the Shangaan tribe of Zimbabwe and plays an important role in many traditional was to identify, analyze the biochemical and microbial changes that occur during production and documenting the whole procedure of Njemani productionfunctions and in ceremonies.an attempt to The upgrade wine is the consumed traditional in a processing variety of flavors to a commercial from sweet scale. to sweet-sour During fermentation and vinegary. microbial The main population aim of the increased research work with fermentation time. The most dominant Lactic acid bacteria were Bacillus, Lactobacillus spp. and Leuconostic species that were responsible for production of inorganic acids and lactic acid during lactic fermentation. Glucobacter and Acetobacter were the dominant Acetic acid bacteria cerevisiae, Saccharomyces pombe, Saccharomyces uvarum and Candida spp, however the most dominant was Saccharomyces cerevisiae and wereidentified responsible and were for responsiblethe conversion for ofacetic sweet acid palm fermentation sap to an alcoholic using alcohol beverage. as Thea substrate. biochemical The parametersyeast species varied identified as fermentation were Saccharomyces progressed Ethanol 0.8%-16.3%, acetic acid 2.8%-7.1%, lactic acid 3.8%-6.9% resulting in Total Titratable Acidity ranging from 0.05% to 0.8% and pH from 6.36 to 3.09. The initial sugar content was 15.7% and dropped to 0.7% after fermentation. If biotechnological techniques are applied to due to the presence mainly of yeasts and lactic acid bacteria. Further research will be needed to isolate and identify all the microbial isolates in Njemani.the production of Njemani a number of benefits will be harnessed. The palm sap fermentation involves alcoholic-lactic-acetic acid fermentation, Keywords: Njemani; Biochemical changes; Microbial changes; Palm wine; Lactic acid; Alcoholic fermentation; Yeasts Introduction muratina (Kenya), Basi (Philippines), pulque (Mexico), ulanzi Palm wine is an alcoholic drink obtained by the natural (Nigeria) have also been studied and documented. Palm wine in fermentation of the sap of various types of palm trees; this Zimbabwe is made from murara tree (Hyphaene petersiana Mart). beverage is produced and consumed in several tropical regions It is also known as Llala in Ndebele, muzira /murara in Shona. of the world, [1]. It plays an important role in traditional practices Other English variations are palm, Real palm and vegetable ivory as an alcoholic beverage, so it is important to determine the physicochemical characteristics and microbiological aspects of its plains. The plant is single stemmed, very tall and stands erect. palm. The plant is a native tree found along the Limpopo flood The leaves are usually crowded on top of the stem. They are fan stage in Zimbabwe, a number of researches have been documented fermentation. Though research in this field is still at its infancy so far both locally and abroad. The following are examples of traditional foods which have been studied, documented and some shaped in short spikes. The female flowers form large sprays The species is very similar and closely related to H. coriacea. Palm commercialized sour milk, Amarula wine, maheu, masvusvu, which develop at the end of the branch next to the male flowers. wine has been produced and consumed in tropical regions of mangisi, ngome doro/hwahwa in Zimbabwe; gari, dawa- dawa, the world for centuries. Palm wine has a pivotal role in the diet, ogi, urwagwa beer among others in East and West Africa. In income and traditional practices of these regions [1, 2, 3]. addition, fermented plant sap juices such as shoto sake (Japan), Adv Biotechnol Microbiol 15(5): AIBM.MS.ID.555921 (2020) 00104 Advances in Biotechnology & Microbiology Palm wine in Zimbabwe is consumed for its nutritional and as containers for tapping/collection of the palm sap. The sap oozed slowly into the container. About 2ml of sap was tapped per was consumed for its nutritional effect because of its probiotic medicinal benefits. Earlier studies by [4] reported that palm wine contents. also reported in their study that palm wine is a good leaves were put in the collecting containers. This was done to slow minute giving a total of 1,440 ml per day. Cut pieces of palm tree source of single cell protein and various vitamins since the micro the rate of fermentation during tapping and collection. biota responsible for fermentation were taken in together with Plant Sap collection and transport from the plantation the wine. That is the reason why pregnant women and breast- feeding women were consuming the palm wine, it’s nutritious The sap was left to collect during the day and during the night. for the foetus and promotes milk production respectively. Fresh Collection was done early mornings at 5:00 am and evenings at palm wine is also consumed as an energy drink. At this stage palm wine is very sweet because of high sugar content, [5]. This the summer season since the temperatures will be high enough 6:00 pm. Collection is more efficient during the day and during to promote tapping and collection process. In the rainy season and beverages and biotechnology in the sense that it focused research contribute to this field of research of fermented foods on the unreported microbial and biochemical changes during winter season, on average 1-2 liters were collected per tree. The sap collected ranges from 2-4 liters per adult tree. In the dry the production of Njemani, a traditional beverage in Zimbabwe. collected sap from each tree was poured in 2-liter plastic gourds. Further research needs to be done on this beverage so as to The samples of the palm wine were taken to the laboratory and were carried in a medical cooler bag with temperatures of 15 °C beyond. to reduce the rate of fermentation before reaching the laboratory. increase the potential benefits economically, medically and Materials and Methods Fermentation The study was carried out in the Eastern part of Masvingo collected palm sap was left to ferment in the gourds with a capacity One thousand and five hundred milliliters (1500 ml) of strip, Malipati-Gezani area, Mwenezi and Chilonga. The data volume of 2 liters in triplicates. The gourds used were borrowed Province specifically in the Shangaan lands of Mahere, Gonarezhou was collected using interviews, participative and experimental from the palm wine brewers. The palm sap was left to ferment for methods. Interviews were done to obtain information on tapping °C - 35 °C). of palm sap and on the procedures in Njemani production from the 48Sample hours analysesin the laboratory at room temperature (32 tappers and Njemani brewers. Interview questions or interview schedules used were similar to those used by researchers in Samples (10 ml) for analyses were collected during tapping and collection of the sap and subsequently after every 6 hours method was ideal since some of the tappers and brewers could not similar studies and were modified to suit this study. The interview parameters were determined: pH, total titratable acid, sugar during fermentation for 48 hours. The following physicochemical The interview augmented the observation method giving valid content, volume of alcohol and the microbiological changes. read and write. This allowed room for probing and clarification. and reliable information. The researcher had the opportunity Biochemical assays to participate and see exactly how the beverage was made. The researcher observed and participated in the process from tapping, All assays where done in triplicate. Titratable acidity was measured immediately. The supernatant (5ml) collected during obtained. Furthermore, the researcher had the opportunity to collection of sap and fermentation until the finished product was twice with distilled water. This solution was titrated against 0.1M note physical characteristics such as the colour of collected sap, fermentation was transferred into a conical flask and diluted the taste and odor etc. The researcher also took note of the time NaOH using phenolphthalein as the indicator. The amount of acid frames in the Njemani production procedures. The data was produced was calculated as percent lactic acid according to the collected when the process was actual happening. This method formula [6]. ml of 0:1 M NaOH normality of NaOH mol weight of acid % lactic acid = ml of sample1 0 interviews. The observation method together with the interview helped the researcher to fill in the information gaps left during method made the data collected very valid and reliable. A Hanna Acidity Titrator (MT682) was also used to verify the results, this is a machine that takes 30 seconds to give accurate TA Tapping reading. The Hanna Acidity Titrator is used by many commercial The palm sap was extracted at an incision made between the wine makers and it is suitable for large batches of samples. The pH kernels. A sharp machete or a knife known as gwese was used to was measured using a pH meter (Hanna, USA). make an incision between the kernels. A lot of effort was needed Measurement of Sugar Content during Njemani to make the incision since the kernels are closely packed forming a Production thick protective layer on the palm stem.