Sorghum Malt Research Articles

Elucidating energy requirements for size reduction of malted maize, soybean and sorghum milling using attrition mill

• High energy efficiency was achieved using attrition mill for grinding malted maize, sorghum and soybean. • Size reduction of malted maize, sorghum, and soybean depend on germination duration and feed rate. • Malted sorghum consumed lowest energy for size reduction while soybean was the highest. • Feed rate of 0.4 kg/h and germination duration of 72 h were most appropriate for malted maize, sorghum, and soybean milling using attrition mill. Malting involves controlled crop steeping, germination and kilning. Energy consumption patterns of milling malted maize, soybean and sorghum grains using attrition mill were investigated. The crops were conditioned to sprout for 24, 48, 72 and 96 h and dried at 60 °C for 18 h. Malted products were fed separately into attrition mill at 0.2, 0.4, 0.6, 0.8 and 1.0 kg/min. Inlet temperature of feed and machine parts, outlet temperature of flour produced and quantity of fuel consumed were recorded in each case. Standard equations were used to quantify energy input, intensity, output and efficiency, exergy loss and destruction. Energy input for milling malted crops germinated for 24, 48, 72 and 96 h respectively ranged from 0.283 to 0.881 MJ, 0.228–0.567 MJ, 0.193–0.578 MJ and 0.186–0.555 MJ for maize; 0.194–0.45 MJ, 0.254–0.379 MJ, 0.153–0.342 MJ and 0.184–0.36 MJ for sorghum, and 0.176–0.661 MJ, 0.373–0.562 MJ, 0.169–0.683 MJ and 0.189–0.617 MJ for soybean. Energy outputs increase with increase in feed rate. Energy utilization efficiencies of the operation ranged from 70.13 to 88.23% for maize, 71.90 to 91.94% for sorghum and 68.88 to 84.99% for soybean. Exergy loss and destruction of the malted crops were significantly different at p < 0.05. This study revealed that energy requirements for size reduction of malted maize, sorghum, and soybean depend on germination duration and feed rate. Attrition mill was appropriate for grinding malted maize, sorghum and soybean, and feed rate of 0.4 kg/h was recommended.

Effect of Malting on the Nutritional Composition, Anti-nutrition Factors and Mineral Composition on Sorghum (Sorghum bicolor)

Background: Sorghum (Sorghum bicolor) is commonly named as Jowar, belongs to family Framineae. The presence of anti-nutrients affect the nutritional values by limiting protein and starch digestibility, hinder mineral bioavailability. This can be reduced by malting procedures. Hence, the study was undertaken to study the effect of malting on nutritional composition, anti nutritional factors and mineral composition. Methods: Processing methods include soaking for 24 hr and germination for different time periods and drying in hot air oven for 2-3 hr. at 50oC. The yield of malted sorghum flour is 95g/100g. Result: Nutrient composition include moisture, protein, fat, ash, crude fibre, carbohydrate and energy showed that the sorghum germinated for 3 days has the higher value of 6.7%, 11.37g, 3.27g, 1g 2.4g 73.57g 375 /100g respectively. The micronutrients i.e. calcium and iron content of malted flour was significantly increased (p less than 0.05) to 28mg/100g, 5.83mg/100g. Anti-nutrients like Tannin and Phytate decreased subsequently in three day germinated sorghum to 61.2mg/100g, 50.625mg/100g respectively. The result showed that processing increases the nutritional, mineral composition and decreases theanti-nutritional factors in sorghum. Hence, Sorghum has potential in fortification of food productsand its suitability of utilization in formulation of value added food products.

Assessment of Malting Performance of Maize and Sorghum of Similar Total Nitrogen Content in Providing the Hydrolytic Enzymes in the Brewing of Gluten-Free Beers

Malted sorghum is used extensively as source of hydrolytic enzymes in brewing gluten-free beers. Malted barley is often used in combination with un-malted maize adjunct (flakes, grits, flours) to brew non-gluten-free beers. Sorghum and maize are similar in many ways. The potential of using malted maize in brewing gluten-free beers was studied. Sorghum and maize of similar total nitrogen content were malted under comparable conditions. Sorghum and maize grains followed some similar patterns in developing hydrolytic enzymes, measured as diastatic power (DP), when malted. Development of diastatic enzymes in both cereals increased with germination period. When mashed, the hot water extract (HWE) for malted sorghum was similar to malted maize when both had five days of germination. For malted sorghum, the HWE value was already reached after two days of germination. The total soluble nitrogen (TSN) for malted sorghum was, for the five germination times studied, half of the TSN values or less than those found for malted maize. Total soluble nitrogen, indicative of the proteolysis achieved during the malting of cereals, showed good proteolysis for the malted maize. The results suggest that like malted sorghum, malted maize could play a similar role in brewing gluten-free beers.

Formulation, Sensory Attributes and Nutrient Content of a Malted Sorghum-based Porridge: Potential for the Management of Moderate Acute Malnutrition among Infants and Young Children

Introduction: Substituting corn in a fortified corn-soy blend (CSB+) with enzyme-active sorghum malt has the potential to be used as a suitable alternative supplementary porridge in the management of infants and young children (IYC) with moderate acute malnutrition (MAM) in Uganda. Objective: This study aimed to develop acceptable malted sorghum-based supplementary porridge (MSBP) that meets the energy and protein specifications for the management of IYC with MAM, using locally-available ingredients. Methods: MSBP formulations included the use of malted sorghum flour and extruded soy and corn flour. The ratio of the soy to corn ingredients was 3:7 (F617/F593), 1:1 (F892/F940), and 4:1 for CSB+, which is the standard care for the management of IYC with MAM in Uganda. The sorghum malt content for F617/F892 and F593/F940 was 25% and 30%, respectively. F617, F593, F892 and F940 met international specifications for a supplementary porridge. A comparison of the consumer acceptability scores and viscosity levels of these formulations was made, using analysis of variance. Results and Discussion: The scores for flavour, taste, mouth feel, sweetness and overall consumer acceptability differed among the formulations (p&lt;0.05). F617 had a higher mean acceptability score than F593, F892 and F940 (p&lt;0.05), as well as a higher energy and protein content than CSB+ (p&lt;0.01). The energy density, protein density and viscosity of F617 were 1.6kcal/ g, 4g/100 kcal and 2809 cP, respectively, with a flour rate of 25%. Conclusion: Sorghum malt is suitable for the development of an acceptable supplementary porridge (MSBP). It meets the international energy and protein specifications for the management of IYC with MAM, and the F617 formulation meets these specifications.

Physicochemical Properties and Consumer Acceptability of Break Fast Cereal Made from Sorghum (Sorghum bicolor L) Soybean (Glycine max), Bambara Groundnut (Vigna subterranean) and Groundnut (Arachis hypogaea)

The present study was aimed at the assessment of physicochemical and consumer acceptability of breakfast cereals developed from locally-sourced materials (sorghum, soybean, Bambara groundnut and groundnut). Ten samples were formulated by mixing the flours in different ratios while the formulated flours were subjected to various analyses including proximate composition, functional properties, vitamins and microbial evaluation and consumer acceptability. The results revealed the following ranges in the proximate parameters: moisture (6.45 – 10.46%), protein (10.26 –19.64%), fat (3.89–11.42%), ash (1.48 – 2.69%), crude fiber (1.94–3.72%), carbohydrates (56.09 – 72.06%), and energy (363.52 – 405.64 Kcal). The functional properties of the formulated breakfast cereal were bulk density (0.65-1.14 g/cm3), water absorption capacity (70.45-82.45 ml/g), swelling index (7.05-10.95%), solubility (73.55-88.84%), and viscosity (22.96-38.84 cP). Appreciable quantities of vitamins were present in the formulated breakfast cereal including vitamins C, B1, B2, B3, and folic acid. The sensory evaluation on the formulated breakfast cereal revealed that sample F (5% Malted sorghum flour + 65% Unmalted Sorghum flour + 30% Soybean flour) was rated the highest in terms of appearance, taste, and overall acceptability. The comparative advantage of this formulated cereal meal is that the ingredients used (soybean, sorghum, Bambara groundnut and groundnut) are easily grown in the tropical areas with high yield and are locally available.

Maize and Sorghum as Raw Materials for Brewing, a Review

Brewing is among the oldest biotechnological processes, in which barley malt and—to a lesser extent—wheat malt are used as conventional raw materials. Worldwide, 85–90% of beer production is now produced with adjuvants, with wide variations on different continents. This review proposes the use of two other cereals as raw materials in the manufacture of beer, corn and sorghum, highlighting the advantages it recommends in this regard and the disadvantages, so that they are removed in technological practice. The use of these cereals as adjuvants in brewing has been known for a long time. Recently, research has intensified regarding the use of these cereals (including in the malted form) to obtain new assortments of beer from 100% corn malt or 100% sorghum malt. There is also great interest in obtaining gluten-free beer assortments, new nonalcoholic or low-alcohol beer assortments, and beers with an increased shelf life, by complying with current food safety regulations, under which maize and sorghum can be used in manufacturing recipes.

Studies on formulation and quality evaluation of weaning food from sorghum malt

In the present investigation attempts have been made to prepare weaning food having low cost, high nutritional value, low viscosity and better acceptability by using sorghum malt. Three weaning foods combination were prepared by using different proportions of sorghum malt flour, mothbean malt flour, sesame flour and skim milk powder. These formulations were subjected to organoleptic evaluation and among the experimental formulations, formulation F1 containing sorghum malt, mothbean malt, sesame flour and skim milk powder in the proportion of 50:30:10:10 was accepted as best considering the highest sensory score (8.28) awarded to it.

Mineral and fibre intake of West African dwarf sheep fed boiled cocoa seed testa and sorghum malt dust in cassava root meal based diets

The study was carried out to investigate the mineral and fibre intake of Sheep fed Cocoa Seed Testa (CST) and Sorghum Malt Dust (SMD) in cassava root meal based diets. The feeding trial was conducted on the feed intake response of West African Dwarf (WAD) sheep in a completely randomized experimental design using boiled CST and SMD based-diets. A total of twenty-eight sheep were randomly allocated to 11 – 13 months of age of CST at 10, 20 and 30% levels, SMD at 10, 20 and 30% levels and a control. The experiment lasted 90 days. Data generated were computed and subjected to a one-way analysis of variance. In the trial, the Neutral Detergent Fibre (NDF), Acid Detergent Fibre (ADF), Acid Detergent Lignin (4DL), Cellulose and Hemicellulose intake increase as the level of CST increased in the diet except for animals in treatment 3 (30% inclusion of CST). Also, NDF, ADF, ADL, Cellulose and Hemicellulose increased as the level of inclusion of SMD increased in the diet except treatment 6 (30% inclusion of SMD). The NDF intake from forage decreased as the level of SMD in the diets. The mineral intake Phosphorus, Calcium, Potassium, Magnesium, Iron, Zinc and Sulphur also followed the same pattern. The mineral intake increased as the level of inclusion of ČST and SMD increased in the diet except in treatment 3 (30% inclusion of CST) and treatment 6 (30% inclusion of SMD) where the value obtained dropped. It was concluded that minerals available in the diets containing boiled Cocoa Seed Testa and Sorghum Malt Dust were significantly (p&lt;0.05) better in their utilization by sheep that consumed boiled Sorghum Malt Dust based diets.

Utilization of malted sorghum sprout, shrimp waste meal and Tephrosia bracteolate hay by West African dwarf sheep fed soybean stover based diets

In a completely randomized design, sixteen (16) West African Dwarf (WAD) rams aged between 10-15 months with an average pre-trial body weight of 14.5 kg were used to study the influence of a compounded concentrate diet (Diet 1), malted sorghum sprout (MSP) (Diet 2), shrimp waste meal (SWM) (Diet 3) and Tephrosia bracteolata hay (Diet 4) as supplement to soybean stover (SBS) + Panicum maximum hay for 13 weeks. The total DM intake was highest (P&lt;0.05) for rams on Tephrosia bracteolata hay (153.89gd-1W0.75) and lowest for those on SWM (137.51gd-1W0.75). the highest (P&lt;0.05) weight gain was recorded for sheep on Tephrosia (41.97gd-1) and lowest for SWM (13.73gd-1). The nitrogen retention of all the rams ranged between 68.53 and 70.65%. The DM digestibility ranged from 0.639 in SWM to 0.692 in concentrate diet. Organic matter digestibility ranged from 0.650 for SWM to 0.695 in concentrate while CP digestibility was 0.654 for SWM and 0.687 in Tephrosia. NDF digestibility varied between 0.563 in SWM and 0.6545 in MSP. Total serum protein (9.0g/dL), blood urea nitrogen(17.85mmol/L), cholesterol (158mg/dl) and plasma glucose (0.53 mmol/L) were significantly (P&lt;0.05) increased in rams fed the concentrate (5.4g/dL, 11.06mmol/l, 15.6mg/dL, 0.38mmol/L), MSP (5.3g/dL, 10.7mmol/L, 152mg/dL, 0.3mmol/L) and Tephrosia (5.0g/dl, 9.63mmol/L, 143mg/dl, 0.3mm0l/L) in that order. It was concluded that these unconventional supplements could be fed with soybeans stover to improve feed intake, nutrient digestibility and nitrogen utilization leading to a better weight gain with sheep.

Blood chemistry and carcass characteristics of finisher broiler chickens fed Malted Sorghum sprout (MSP) or Wheat-offal based diets supplemented with yeast culture and enzyme

This experiment was conducted to determine the blood chemistry and carcass characteristics of broilers fed malted sorghum sprouts (MSP) or wheat offal (W/O)-based diets supplemented with yeast culture and enzyme. A total of two hundred and forty 28-day old, Marshal Broiler chickens used for the experiment were randomly allotted to 8 dietary treatment groups of 30 birds each. Each treatment group was replicated thrice with 10 birds per replicate. Data on selected blood indices and carcass traits of the birds were collected during the course of the feeding trial that lasted for 4 weeks. The experiment was a 2X4 factorial consisting of two (2) test ingredients (MSP and wheat offal) at 4 inclusion levels of enzyme or yeast (0g kg-1, +0.01gkg-1 yeast and Roxazyme G2(G) enzyme, +0.01gkg-1 yeast ,+ Roxazyme G2(G) enzyme. At the end of the trial, the effect of MSP and wheat offal inclusion showed a significant effect (P&lt;0.05) for uric acid, WBC, Total protein, albumin and globulin. However, uric acid, total protein, Albumin and Globulin were highest for wheat offal diet. Furthermore, the results show that values obtained for white blood cell, uric acid, total protein, albumin, globulin, creatinine, ALT&amp; AST were significantly (P&lt;0.05) affected by the enzyme, yeast and their combination. The carcass results show that none of the parameters measured differed significantly. In conclusion, supplementation with yeast + enzyme improves total protein, albumin and globulin. Meanwhile, it reduced concentrations of uric acid, ALT and AST by broiler chickens. Therefore MSP diet should be supplemented with yeast+ enzyme or enzyme singly to improve Livestock ration for better utilisation.

Development of beer from malted sorghum (Sorghum bicolor)

Sorghum (Sorghum bicolor) is a gluten free, whole grain rich in complex carbohydrates and minerals. Its consumption is limited due to lack of adoption in diversified food products and easy availability of other chief cereals. So study was undertaken to produce Beer using sorghum grain by malting technique. Beer, the complex brewed beverage made from malt (germinated grains), hops, water, and yeast, which provides hydrolytic enzymes (especially amylases) to ferment sugars into ethanol and carbon dioxide. Grain sorghum samples were procured and processed by malting at different periods, then ground into flour and analyzed for Starch, reducing sugar and amylase activity, It ranged from 56.33 to 37.44 percent, 25 to 53.25mg/g, 20.44 to 34.50 µmol/min/ml, respectively. The Highest Amylase activity and Reducing sugar was obtained in 72hr germinated sorghum, So Beer was developed using 72hr malted sorghum at different proportion (40%, 60%, and 100%). 100% barley Beer was taken as control.. And Chemical parameters such as PH, TSS, alcohol, color, and brightness were analyzed, PH ranged from 3.17-4.1, TSS Ranged from 15 to 7 brix, alcohol content ranged from 6.25 to 6.5 per cent. The Highest Alcohol Content Obtained in 60% Incorporated beer. Mean sensory scores revealed that incorporation of malted sorghum flour at 60 per cent is highly accepted viz. appearance, color, aroma, bouquet, flavor, astringency, general quality and overall acceptability. Therefore sorghum is best substitute for barley to develop Shelf Stable beverage to provide commercially viable products that will increase the utilization of sorghum in industrial purposes.

Screening of Ghanaian sorghum varieties for lager style brewing

Although sorghum is widely cultivated in Africa, its utilisation for the production of lager type beer by breweries is relatively limited. Sorghum is used unmalted as a brewing adjunct, in limited quantities, with barley and commercial exogenous enzymes for lager type beer production. The use of sorghum malt as the sole raw material in brewing lager type beers is generally limited because of its low diastatic power and high tannin content among other factors. The objective of this study is to identify sorghum varieties that could be malted and used as the sole (100%) brewing material for lager beer production. Twenty-six sorghum varieties cultivated in Ghana were screened for malting and brewing potential based on germinative energy, green malt hydration, gelatinisation temperature, extract yield, limit attenuation, free amino nitrogen and diastatic power. Five of the varieties; Kadaga, Nakpaji, Kazea Nanga, Global 2000 and Kyere, of the twenty-six evaluated were found to have desirable characteristics for producing quality malt for lager beer production without the need for supplementary enzymes. Pilot scale malting and brewing trials are recommended to validate these findings.

Nitrogen utilization by male WAD sheep fed graded levels of boiled CST and SMD based diets

The study was carried out to investigate the nitrogen utilization by male West African Dwarf (WAD) sheep fed boiled Cocoa Seed Testa (CST) and Sorghum Malt Dust (SMD)-based diets. Twenty-eight male animals were divided into seven groups with similar average initial live weight in a completely randomized design. Each group contained four animals. The trial consisted of seven dietary treatments which comprised CST at 10, 20 and 30% levels, SMD at 10, 20 and 30% levels and a control. The trial lasted for 90 days. Data generated were subjected to a one-way analysis of variance. Apparent nitrogen intake (19.41g/d) and retention (9.67g/d) were significantly (P&lt;0.05) higher in the treatment with 20% SMD. Generally, dietary inclusion of CST and SMD improved the nitrogen intake by male WAD sheep with the best result from sheep fed 20% sorghum malt dust based diets.

Processing methods of malted sorghum sprout impacts on the nutritive values

The separated roots and shoots left after malt extraction from the young sorghum seedlings are collectively called Sorghum sprout and being regarded a waste. The study was designed to investigate the effect of different processing methods on the nutritive value of malted sorghum sprout (MSP). TheMSP was divided into three parts: raw (RMSP), alkaline (wood ash) treated (AMSP) and fermented (FMSP). The proximate composition, fibre fraction and the mineral contents were determined and all data obtained were subjected to one way analysis of variance. Results revealed that the proximate and fibre fraction values of MSP were significantly (p&lt;0.05) influenced by the processing methods. The highest dry matter (82.34%), ether extract (1.76%), ash (15.52%), neutral detergent fibre (63.00%) and hemicellulose (39.00%) values were recorded in FMSP. Fermentation and alkaline treatments reduced the crude protein while it increased the ether extract and nitrogen free extract of theMSP.Ash had the highest percentage value in fermentedmalted sorghum sprout (FMSP) and the lowest in raw malted sorghum sprout (RMSP). The concentration (g/kg) of calcium (14.45), phosphorus (67.92) and potassium (6.59) were significantly (p&lt;0.05) highest in FMSP. The concentration (mg/kg) of iron (947.50) and copper (21.50) observed in AMSP were significantly (p&lt;0.05) higher than the values obtained in FMSP followed by RMSP. It was observed that fermentation and alkaline treatment employed reduced zinc concentration values of the MSP. It can be concluded that fermentation processing method used in this study presented the best results in terms of the chemical andmineral composition values.

Performance and blood indices of West African dwarf goats fed graded levels of malted sorghum sprout with enzyme supplementation

Malted sorghum sprout (MSP) is an agro-industrial by-products rich in organic nitrogen and amino acids which can be used to enhance ruminant nutrition. A study was conducted to assess the nutritive value of MSP as supplementary on the performance characteristics and blood profile of West African dwarf (WAD) goats. MSP was collected, air-dried and then incorporated at different inclusion levels of 0, 10, 20 and 30% to formulate four dietary treatments T , T , T and T , respectively, with T - T being supplemented with Roxazyme G2 1 2 3 4 2 4 enzyme at 0.5g/kg. Twelve WAD bucks with an average weight of 7±0.5kg were assigned into four dietary treatments with three bucks per treatment in a completely randomized design over a period of 84 days. Data were obtained on performance characteristics, haematological and serum biochemical indices. Performance characteristics showed that average concentrate consumed (229.04g/day) and average daily weight gain (44.44 g/day) of WAD goats were significantly (P?0.05) higher in goats fed 20% MSP with enzyme supplementation. Dietary MSP with enzyme supplementation significantly (P?0.05) influenced the total protein (TP), aspartate amino transferase (AST), alanine amino transferase (ALT), white blood cells (WBC) and red blood cells (RBC) across the treatments. 3 3 TP (7.05g/dL) and WBC (7.88 x 10 /mm ) were significantly (P?0.05) higher in goats fed 20% MSP while globulin values increased significantly (P?0.05) across the dietary treatments (3.94 – 5.05g/dL) and is within the normal levels expected of healthy goats. It is concluded that dietary MSP with enzyme supplementation at 20% improved the performance, hematological and serum biochemical indicess of WAD goats without any adverse effects.

Intake, digestibility and nitrogen utilization of West African dwarf goats fed diets containing graded levels of alkaline treated malted sorghum sprout

A twelve-week trial was conducted to determine the nutrients intake, digestibility and nitrogen utilization of West African dwarf (WAD) goats fed diets containing graded levels of alkaline treated malted sorghum sprout (AMSP) using Panicum maximum as the basal diet. A total number of sixteen (16) WAD goats with an average live weight; 5.8 ± 0.6 kg were allotted on weight equalization into four (4) dietary treatments consisting of four goats per treatments in a completely randomized design. Four (4) diets were formulated to contain 0, 20, 40 and 60% AMSP. Data was collected on nutrients intake, digestibility and Nitrogen utilization parameters. Significant difference (P&lt;0.05) were observed in all the nutrient intake parameters observed except for dry matter intake. Goats fed 40% AMSP recorded the highest total ash intake (27.01%), total acid detergent fibre (11.46%) and total cellulose intake (83.13%) compared with other dietary treatments. There was no significant difference (P&gt;0.05) in all the nutrient digestibility parameters except the ether extract, ash, cellulose and hemicellulose. The highest Ash (66.16%), cellulose (82.47%) and hemicellulose (82.26%) contents were obtained in goats fed 40% AMSP. There were no significant differences (p&gt;0.05) among the Nitrogen metabolism variables observed except total nitrogen intake and nitrogen balance. Goats fed 40% AMSP based diet recorded the highest Nitrogen retention (62.18%). It can therefore be concluded that 40% AMSP can be used as potential sources of supplements in ruminants feed most especially during dry season as it enhanced nutrient intake, digestibility and nitrogen balance.

Sorghum Malt Extract as a Growth Medium for Lactic Acid Bacteria Cultures: A Case of Lactobacillus plantarum MNC 21.

Cultivation of lactic acid bacteria cultures is vital for research and commercial production of fermented foods. However, the conventional growth media used are generally costly. Malt extracts from four sorghum varieties (SESO 1, SESO 3, Epuripur, and Eyera) were evaluated as alternative low-cost growth media for Lactobacillus plantarum MNC 21. Saccharified sorghum malt extracts were inoculated with 4 log cfu/mL MNC 21 and incubated at 30°C for 24 h. MRS broth was the reference medium. Microbial counts, pH, titratable acidity (TA), free amino nitrogen (FAN), and total sugars were measured. Maximum microbial counts in the extracts and MRS broth were 9 and 10 log cfu/mL, respectively. Maximum growth rate in the extracts was 0.7–0.9 log cfu/mL/h and 0.8 log cfu/mL/h in MRS broth. The final pH of the extracts was 3.5–3.6, with an overall increase in TA of 1.2% in Epuripur and 0.2% in other varieties. Final pH and TA of MRS broth were 4.1 and 1.3%, respectively. Total sugars dropped by 95.2% and FAN by 2.1% in MRS broth. In contrast, total sugars and FAN dropped by 5.6–9.1% and 24.9–32.7% respectively, in the extracts. Sorghum malt extracts can be adopted as alternative low-cost growth media for lactic acid bacteria cultures.

APPLICATION OF REFRIGERATED AND FROZEN SORGHUM MALT SLURRIES IN THE PRESERVATION OF STARTER CULTURES FOR OBUSHERA FROM UGANDA

Industrial production of traditional fermented beverages is limited by lack of quality commercial starter cultures. Saccharomyces cerevisiae MNC21Y and Lactobacillus plantarum MNC21 can be used to ferment cereal beverages such as Obushera . These cultures are unavailable as commercial starters due to lack of appropriate propagating and distributing procedures. The purpose of this study was to evaluate the use of refrigerated and frozen sorghum slurries as carrier media for the starters. Starters were propagated in sorghum slurries (30°C for 24 h) and stored at 5°C and -18°C for 90 days. Viability of Saccharomyces cerevisiae and Lactobacillus plantarum was determined by cell counts after surface plating and pour plating, respectively. Fermentation ability was determined by inoculating sorghum slurries with starters and monitoring pH, acidity and flavor development . Viability was higher for starters stored at 5°C (S. cerevisiae : 6 log cfu.g -1 and Lb. plantarum : 7-9 log cfu.g -1 during 90 days) than those at -18°C (S. cerevisiae : 2 cfu.g -1 and Lb. plantarum : 4 log cfu.g -1 after 30 days). Refrigerated starters acidified Obushera (pH £ 4.5) faster (10-20 h) than frozen ones (18-24 h). Refrigerated or frozen S. cerevisiae + Lb. plantarum starters in sorghum malt slurries can remain viable for at least one or three months, respectively and produce Obushera with characteristic flavors.

Detection of mycotoxins in opaque beer production

In Zimbabwe opaque beer is one of the most common alcoholic beverages. This study was aimed at detecting aflatoxins and Ochratoxin A (OTA) in commercial opaque beer brewing. Aflatoxins and OTA are mycotoxins produced by fungi. Maize, sorghum malt and opaque beer samples were used for microbiological plating and multi mycotoxin extraction. Aflatoxins, OTA, Aspergillus spp, total viable count, coliforms, Lactobacillus spp, Salmonella, Shigella, Staphylococcus aureus were assessed. Mycotoxins were separated using an High Performance Liquid Chromatography (HPLC). Aflatoxins were not detected in all the samples. OTA concentration for malt was 18 μg/kg, 5.2 μg/kg in beer and absent in maize. Fungi identified in maize were Aspergillus flavus, Aspergillus niger, Aspergillus carbonarius, and Aspergillus fumigatus. Malt contained Aspergillus flavus and Aspergillus carbonarius. Fungi observed in beer were Aspergillus flavus and Aspergillus niger. The beer may need heat treatment methods in order to remove the microorganisms identified and prolong shelf life of the product.

Use of Aspergillus oryzae during sorghum malting to enhance yield and quality of gluten-free lager beers

Sorghum has been used for brewing European beers but its malt generally lower beer yields and alcohol contents. The aim of this research was to produce lager beers using worts from sorghum malted with and without Aspergillus oryzae inoculation. Worts adjusted to 15° Plato from the sorghum malt inoculated with 1% A. oryzae yielded 21.5% and 5% more volume compared to sorghum malt and barley malt worts, respectively. The main fermentable carbohydrate in all worts was maltose. Glucose was present in higher amounts in both sorghum worts compared to barley malt worts. Sorghum–A. oryzae beer had similar specific gravity and alcohol compared to the barley malt beer. Sorghum–A. oryzae beer contained lower amounts of hydrogen sulfide, methanethiol, butanedione, and pentanedione compared to barley malt beer. Sorghum–A. oryzae lager beer had similar yield and alcohol content compared to the barley malt beer but differed in color, key volatiles and aromatic compounds.