Microbiological and physico-chemical characteristic of Rwandese traditional beer “Ikigage”

Samples of traditional sorghum beer Ikigage was collected in the southern province of Rwanda and analyzed for microbiological and physico-chemical contents. Ikigage contained total aerobic mesophilic bacteria (33.55 x 106 cfu/ml), yeast (10.15 x 106 cfu/ml), lactic acid bacteria (35.35 x 104cfu/ml), moulds (4.12 x 104 cfu/ml), E. coli (21.90 x 103 cfu/ml), fecal streptococci (22.50 x 103 cfu/ml), Staphylococcus aureus (16.02 x 103 cfu/ml), total coliform (32.30 x 103 cfu/ml), ethanol, soluble protein,reducing sugars, total acidity, pH and Brix were 2.2% (v/v), 9.2 g/l, 2.3, 1.7%, 3.9 and 11.5 bx, respectively. The yeast was identified by API 20 C test and confirmed by PCR-Sequencing of ITS-5.8S region of rDNA. Seventy yeasts isolated in the samples were found to belong to either Saccharomyces cerevisae, Candida inconspicua, Issatchenkia orientalis, Candida magnolia and Candida humilis. Lactic acid bacteria were identified using the API 50 CHL system. Ten different isolates of lactic acid bacteriabelonged exclusively to the genus Lactobacillus: Lactobacillus fermentum, Lactobacillus buchneri, and Lactobacillus sp. The micro-organisms of fecal origin are from the water and the operations postfermentation process. The presence of potential pathogens emphasizes the importance of developing starter cultures with GRAS status for commercialization of ikigage

Hospital acquired infections in pediatrics unit at Butare University Teaching Hospital (CHUB)

Background: Hospital acquired infection (HAI) also called nosocomial infection is an infection acquired in hospital or other healthcare facilities. HAIs are a major public health problem all over the world, but particularly in developing nations and they are among the major causes of death and increased morbidity among hospitalized patients. It was found that HAI in sub-Saharan Africa is the major cause of illness and death in children.Aim: The aim of this study was to provide knowledge on the prevalence of hospital acquired infection in pediatric unit of the University Teaching Hospital of Butare (Rwanda).Methods: Hospital acquired infections surveillance method and definition of infections described by CDC/NHSN were used.Results and conclusion: This study showed that the prevalence of HAI was very high (12.1 %) and the main bacteria causing NIs in pediatric unit were Kleblesiela pneumonia, followed by E. coli and Staphylococcus aureus. Low Respiratory HAIs were the most prevalent.Keywords: Prevalence, Hospital Acquired infection, Pediatric

Antimicrobial activity and phytochemicals analysis of vernonia aemulans, vernonia amygdalina, lantana camara and markhamia lutea leaves as natural beer preservatives

Background: African traditional beers are both considered as food and beverages for African people and hence preserving them using the natural additive is of utmost importance. In the present study, the antimicrobial activity of aqueous and ethanol extracts of Rwandan plants Vernonia aemulans, Vernonia amygdalina, Lantana camara and Markhamia lutea leaves were tested against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium and Sacharomyces cerevisiae. Methodology: The antimicrobial activity was carried out by the disc diffusion method. The phytochemical screening of ethanolic extracts of these Rwandan plants was determined using standard method of analysis. Result: The results showed that the ethanol and aqueous extracts of V. aemulans, V. amygdalina, L. camara and M. lutea leaves have antibacterial activity against food spoilage bacteria and food-borne pathogens with inhibitory zone diameters ranging between 3-26 mm. All extracts analyzed did not possess antimicrobial activity against S. cerevisaie, which plays major role in African beers fermentation. The Gram-negative bacteria tested were found to be resistant only against the extracts of M. lutea leaves. The extracts of V. aemulans, V. amygdalina and L. camara possess antibacterial activities both against the Gram-positive (B. subtilis and S. aureus) and negative (E. coli and S. typhimurium) bacteria with the minimum inhibitory concentration ranging from 2-16 mg mL-1. These inhibitory properties had been attributed to the presence of tannins (9.2-99 mg g-1), flavonoids (62.4-87.4 mg g-1), saponins (39.8-65 mg g-1), phenolic compounds (22.6-42.8 mg g-1) and alkaloids (32-40.7 mg g-1) in these plants. Conclusion: The findings established that V. aemulans, V. amygdalina and L. camara leaves can be used as natural beer preservatives with considerable market opportunities in African brewing industry due to their strong antimicrobial activity imparting extended shelf-life with less harmful effects. © 2017 Francisco Abel Lemos Alves et al

Mashing with unmalted sorghum using a novel low temperature enzyme system: impacts of sorghum grain composition and microstructure

Brewing lager beers from unmalted sorghum traditionally requires the use of high temperature mashing and exogenous enzymes to ensure adequate starch conversion. Here, a novel low-temperature mashing system is compared to a more traditional mash in terms of the wort quality produced (laboratory scale) from five unmalted sorghums (2 brewing and 3 non-brewing varieties). The low temperature mash generated worts of comparable quality to those resulting from a traditional energy intensive mash protocol. Furthermore, its performance was less dependent on sorghum raw material quality, such that it may facilitate the use of what were previously considered non-brewing varieties. Whilst brewing sorghums were of lower protein content, protein per se did not correlate with mashing performance. Rather, it was the way in which protein was structured (particularly the strength of protein starch interactions) which most influenced brewing performance. RVA profile was the easiest way of identifying this characteristic as potentially problematic

Traditional sorghum beer "ikigage"

peer reviewedSamples of traditional sorghum beer Ikigage was collected in the southern province of Rwanda and analyzed for microbiological and physico-chemical contents. Ikigage contained total aerobic mesophilic bacteria (33.55 x 106 cfu/ml), yeast (10.15 x 106 cfu/ml), lactic acid bacteria (35.35 x 104 cfu/ml), moulds (4.12 x 104 cfu/ml), E. coli (21.90 x 103 cfu/ml), fecal streptococci (22.50 x 103 cfu/ml), Staphylococcus aureus (16.02 x 103 cfu/ml), total coliform (32.30 x 103 cfu/ml), ethanol, soluble protein, reducing sugars, total acidity, pH and Brix were 2.2% (v/v), 9.2 g/l, 2.3, 1.7%, 3.9 and 11.5 bx, respectively. The yeast was identified by API 20 C test and confirmed by PCR-Sequencing of ITS-5.8S region of rDNA. Seventy yeasts isolated in the samples were found to belong to either Saccharomyces cerevisae, Candida inconspicua, Issatchenkia orientalis, Candida magnolia and Candida humilis. Lactic acid bacteria were identified using the API 50 CHL system. Ten different isolates of lactic acid bacteria belonged exclusively to the genus Lactobacillus: Lactobacillus fermentum, Lactobacillus buchneri, and Lactobacillus sp. The micro-organisms of fecal origin are from the water and the operations postfermentation process. The presence of potential pathogens emphasizes the importance of developing starter cultures with GRAS status for commercialization of ikigage

Characterisation and improvement of the quality of Rwandese traditional beer « ikigage » made from sorghum

Ikigage is a Rwandese traditional beer made from sorghum malt and local plants, mainly Vernonia amygdalina “umubirizi”. However, this beer remains less attractive than Western beers of pils type because of poor hygienic quality, variations of organoleptic quality and limited shelf life. The aim of this work is to characterize ikigage beer in order to improve its hygienic quality and to reduce the organoleptic variations using the local raw materials. The first part of our study shows that ikigage beer marketed in Rwanda is characterized by the presence of Stapylococcus aureus and many micro-organisms of fecal origin (Escherichia coli and fecal streptococci), by the low ethanol content, high total acidity and an important amounts of proteins. The yeasts (Saccharomyces cerevisiae and Issatckenkia orientalis), followed by the lactic acid bacteria (Lactobacillus fermentum and Lactobacillus buchneri), are the predominant microorganisms involved in fermentation of ikigage beer fermentation. Besides, one of the major problems in sorghum beer brewing is the efficient conversion of the starch extracts into fermentable sugars due to the weak activity of β-amylase in sorghum malt. The use of Eleusine coracana “uburo” (Musama variety) malt (30%), associated with mashing decantation procedure, increases the content of sugar fermentable, maltose particularly, in sorghum wort, and consequently ethanol content in the beer. The second part of our study shows that V. amygdalina, known for its antibacterial properties and its bitterness similar to hops, contributes to the production of methyl salycilate, beta-damascenone and many terpenes compounds (δ-3-carene, β-farnesene, farnesol, β-citronellol and linalool), in the sorghum beer “ikigage”. This work reveals also the presence of 14 polyfunctional thiols in beers brewed with ‘non-Western’ raw materials. Among them, the well-known hop constituent 3-methyl-2-buten-1-thiol emerged as a key flavour in the unhopped beers containing V. amygdalina. V. amygdalina also contributes to the production of 1-butanethiol and 4-sulfanyl-4-methyl-2-pentanone in sorghum beer. However, contrary to hops, V. amygdalina addition during boiling also appears to strongly inhibit the production of 2-sulfanylethyl acetate. The third part of our study shows that the use of S. cerevisiae in combination with I. orientalis and L. fermentum as starter allows producing ikigage beer having the GRAS (generally recognized as safe) statute while preserving the organoleptic characteristics similar to those of local traditional beer “ikigage” produced by peasants

Microbiological and physico-chemical characteristic of Rwandese traditional beer «Ikigage»

peer reviewe

Characteristics of African traditional beers brewed with sorghum malt: a review

Traditional sorghum beers are produced in several countries of Africa, but variations in the manufacturing process may occur depending on the geographic localization. These beers are very rich in calories, B-group vitamins including thiamine, folic acid, riboflavin and nicotinic acid, and essential amino acids such as lysine. However, the traditional sorghum beer is less attractive than Western beers because of its poorer hygienic quality, organoleptic variations and shorter shelf life. Research into the microbiological and biochemical characteristics of traditional sorghum beers as well as their technologies have been performed and documented in several African countries. This review aims to summarize the production processes and compositional characteristics of African traditional sorghum beers (ikigage, merissa, doro, dolo, pito, amgba and tchoukoutou). It also highlights the major differences between these traditional beers and barley malt beer, consumed worldwide, and suggests adaptations that could be made to improve the production process of traditional sorghum beer

Occurrence of polyfunctional thiols in sorghum beer "ikigage" made with Vernonia amygdalina "umubirizi"

Several polyfunctional thiols have been previously identified in beers made from barley and hops. These compounds have not been investigated in beers brewed with non-Western raw materials. Here we have performed a thiol-specific extraction with p-hydroxymercuribenzoic acid on a traditional ikigage sorghum beer from Rwandese peasants (use of Vernonia amygdalina just for yeast propagation), and on two pilot beers with addition (or not) of V. amygdalina in the boiling kettle, instead of hops. Gas chromatography – olfactometry, gas chromatography –mass spectrometry and gas chromatography with pulsed flame photometric detectionanalyses of the extracts enabledustoidentify 14polyfunctional thiols.The well-known ho pconstituent3-methyl-2-buten-1-thiol emerged as a key flavour in the unhopped beers containing V. amygdalina flavour dilution >262 144). The addition of V. amygdalina during boiling also resulted in the presence of 1-butanethiol, but the production of 2-sulfanylethanol and 2-sulfanylethyl acetate was inhibited. Complementary data are required to understand how V. amygdalina leaves are able to impact upon the Ehrlich pathway leading to cysteine and homocysteine-derived thiols