Literatura académica sobre el tema "Fermeted beverages"

Globally, fermented beverage and condiments are made by using different conventional practices, raw materials, and microorganisms. This paper presents the available literature review on the technology and microbiology of traditional Ethiopian beverages and condiment products. Traditional fermented beverage and condiment products have essential vitamins, minerals, enzymes, and antioxidants that are all enhanced through the process of traditional fermentation practices. In Ethiopia, fermented beverage and condiment products have practiced in a long history. During the production of traditional fermented beverage and condiment products, controlled natural fermentation process with the absence of starter cultures are used to initiate it. Moreover, the preparation of many traditionally fermented beverage and condiment products is still practiced in a household art, thereby a wide variety of fermented beverages and condiments are consumed in Ethiopia. In conclusion, the review discusses the nature of the beverage and condiment preparation, poor traditional household processing, and the extent and limitation of scientific work done so far and suggests some recommendations to limit the problem in Ethiopia.

Background Functional fermented beverages are popular worldwide due to their potential to promote health. Starter culture is the main determinant of the final quality and flavor of fermented beverages. The co-cultivation of lactic acid bacteria (LAB) and yeast makes a significant contribution to the safe flavor of fermented beverages. However, the research on the potential of antioxidant, antimicrobial, and anti-biofilm formation of strawberry fermented beverage obtained by combining the LAB and yeast as starter cultures has not been well explored. Methods In this study, LAB and yeast were combined as starter culture to obtain strawberry fermented beverage. Fourier transform infrared (FTIR ) spectroscopy was used for the qualitative analysis of the fresh strawberry juice and fermented beverage. From the changes in antioxidant content, free radical scavenging ability, total superoxide dismutase (T-SOD) activity and total antioxidant capacity (T-AOC) to evaluate the antioxidant capacity of fermented beverage in vitro. The antibacterial ability was tested by the Oxford cup method. The biofilms of Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538 under fermented beverages treatment was observed by Fluorescence microscope. In addition, sensory analysis was conducted in this study. Results In this study, the absorption peaks of Fourier transform infrared between 1,542 cm−1 and 976 cm−1, suggest the existence of organic acids, sugars and ethanol. The total phenols and total flavonoids content decreased by 91.1% and 97.5%, respectively. T-SOD activity increased by 33.33%.The scavenging ability of fermented beverage on superoxide anion free radicals was enhanced, and the scavenging ability on DPPH free radicals, hydroxyl free radicals, and ABTS free radicals was weakened. However, the T-AOC increased from 4.15 ± 0.81 to 8.43 ± 0.27 U/mL. Fermented beverage shows antibacterial activity against four pathogens. The minimum inhibitory concentration (MIC) values of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 6538 were 0.05 mL/mL and 0.025 mL/mL, respectively, and the minimum bactericidal concentration (MBC) were both 0.2 mL/mL. It was observed by fluorescence microscope that the green fluorescence area of the two biofilms is greatly reduced after being treated with fermented beverage. Sensory analysis results show that the average scores of fermented beverage in color, appearance and taste were increased. The overall impression and flavor were decreased. Conclusion These results demonstrated that strawberry fermented beverage has potential benefits such as an antioxidant, antibacterial, and anti-biofilm formation, providing the potential for the fermented beverage to become promising candidates for natural antioxidants, antibacterial agents and anti-biofilm agents.

Ethiopia is one of the countries where a wide variety of traditional fermented beverages are produced and consumed for a long time. Traditional fermented beverages are those which are indigenous to a particular area and have been developed by the people using age-old techniques from locally available raw materials. Some of Ethiopian indigenous traditional fermented beverages products are Cheka, Keribo, Borde, Areki, Tella, Shamita, Booka, and Korefe, in which fermentation is natural and involves mixed cultures of microbes. The most common fermenting microorganisms, lactic acid bacteria and yeast, are used as probiotics, for improvement of organoleptic properties, for provision of nutritional quality and biopreservative. The nature of beverage preparation in Ethiopia, traditional household processing, associated microorganisms with a fermented beverage, and their contribution toward improving the nutritional value and safety, the extent, and its prospect in supporting the livelihood of people in Ethiopia need concern. Therefore, in the future, to improve its quality, it is important to standardize the methods of beverage fermentation processes.

The aim of this paper is to determine nutritive, functional, microbiological and sensory properties of probiotic beverages produced from different volume ratios of cow's milk and soy beverage (25:75, 50:50 and 75:25). Pure cow’s milk and soy beverage served as control samples. Fermentation was performed at 43 °C by a combined culture consisting of the probiotic strain Lactobacillus acidophilus La5 and yoghurt culture. Viable counts of La5 strain in the produced beverages ranged from 7.52 to 8.20 log CFU/mL, which is above the probiotic minimum (106 CFU/mL). Lactic acid was the most prevalent organic acid in all samples (660.1 to 1003.0 mg/100 mL). The fatty acid profiles of fermented beverages were as follows: the mass fraction of saturated fatty acids was 22.2–82.7 %, of unsaturated fatty acids 22.3–77.8 % and of polyunsaturated fatty acids 15.5–65.9 %. The main soy sugars were transformed well (80 % stachyose and 50 % raffinose conversion) into lactic acid during fermentation. Functional probiotic beverages were successfully produced from different volume ratios of cow's milk and soy beverage by L. acidophilus La5 and yoghurt culture. Mixing cow's milk with soy beverage significantly improved the sensory properties of the product, especially its smell, taste and colour. The acceptability test showed good acceptance by potential consumers of all fermented beverage samples except for the sample made from 100 % soy beverage. In the end, the obtained results represent a good basis for optimisation of the ideal volume ratios of cow's milk and soy beverage for production of fermented beverages characterised by good viability of probiotic bacteria as well as by good functional, nutritive and sensory characteristics.

The objective of this study was to develop a fermented dairy beverage flavored with araticum pulp, assess its physicochemical characteristics, microbiological quality, and sensory preference by the consumer. Araticum pulp was prepared using two different methods: with or without bleaching (50 ºC/5 minutes). Formulations of fermented dairy beverages consisting of whey (50%), standardized pasteurized milk (50%), and seven different concentrations of bleached araticum pulp (5.0, 7.5, 10.0, 12.5, 15.0, 17.5, and 20.0% w/v) were prepared. In addition, seven formulations of fermented dairy beverage, without adding araticum pulp, and consisting of varying proportions of whey (40, 50, 60, 70, 80, 90, and 100%) were developed. In all formulations, thickeners/stabilizers were added. All araticum pulp samples (with and without bleach) and fermented dairy beverages (with and without araticum pulp) were analyzed for the relevant physicochemical properties: pH, titratable acidity, acidity of pulp, acidity of fermented beverage, moisture, ash, fat, protein, crude fiber, ascorbic acid, carbohydrates, total solids, and caloric values. Microbiological counts of coliforms at 35 °C and 45 °C in the pulp and beverage, and molds and yeasts and Salmonella sp. in the pulp were obtained. Additionally, sensory analysis regarding preferences of the different fermented dairy beverage formulations was also performed. The araticum pulp samples without bleach, showed higher values of pH, moisture, protein, total fiber, and ascorbic acid, as compared to bleached pulp samples, while bleached araticum pulp showed higher values for other physicochemical parameters. Microbiological results showed that all pulps and fruit-dairy beverages were suitable for consumption. It was found that there was no significant consumer preference between different fermented beverage formulations, according to the different percentages of pulp. However, the formulations consisting of 40, 50, 60, and 70% whey were preferred over the one consisting of 100% whey.

The development of functional fermented beverages enriched with γ-aminobutyric acid (GABA) has been pursued because of the health benefits of GABA; however, few studies have described GABA production by yeast. Therefore, this study aimed to produce fermented apple beverages enriched with GABA produced by Saccharomyces cerevisiae SC125. Golden Delicious apples were fermented by S. cerevisiae SC125 to produce a novel functional beverage; commercial yeast was used as the control. The GABA, organic acid, and volatile compound content during the fermentation process was investigated by high-performance liquid chromatography and headspace solid-phase microextraction/gas chromatography-mass spectrometry. A yield of 898.35 ± 10.10 mg/L GABA was achieved by the efficient bioconversion of L-monosodium glutamate. Notably, the S. cerevisiae SC125-fermented beverage produced several unique volatile compounds, such as esters, alcohols, 6-decenoic acid, and 3-hydroxy−2-butanone, and showed significantly enhanced contents of organic acids, including malic acids, citric acid, and quinic acid. Sensory analysis demonstrated that the S. cerevisiae SC125-fermented apple beverage had improved aroma, flavor, and overall acceptability. In conclusion, a fermented functional apple beverage containing GABA was efficiently produced using S. cerevisiae SC125.

Hylocereus lemairei (Hook.) is a plant popularly known as pitaya-purple, whose fruits are known as dragon fruit. This paper aimed to carry out the physical-chemical and chemical characterization of fermented beverages based on H. lemairei fruits. Fermented beverages were elaborated using two different commercial yeasts of Saccharomyces cerevisiae [Biolievito Bayanus (BB) and Arom Cuvée (AC)] and were characterized by NMR. In addition, the antioxidant capacity (DPPH and ABTS) and Total Phenolic Content (TPC) based on the Folin Ciocalteu method were determined. According to the legislation, the fermented beverages from BB and AC showed alcoholic levels of 12.9 and 12.5% (v/v) and pH of 3.9 and 3.8, respectively. The chemical compounds of both beverages were similar, whose major organic compounds are glycerol, myo-inositol, tyrosol, and citric and succinic acids. According to the DPPH and TPC evaluation, BB beverage (248.3 µM TE and 117.6 mg GAE L-1) presented higher antioxidant capacity when compared to the BC beverage (219.8 µM TE and 108.4 mg GAE L-1). In the ABTS assay, both beverages were not statistically different (p < 0.05). Tyrosol may be responsible for increasing the antioxidant capacity and phenolic compounds content when compared to the control juice used to prepare fermented beverages.

One of the most economical ways of whey processing is the production of beverages, that represents a single process that exploits all the potential of whey as a raw material. Functional and sensory characteristics of whey based beverages are a criterion that is crucial to the marketing of products and win over consumers. The aim of this study was to determine nutritional and functional characteristics of fermented whey beverage with milk and commercial ABY-6 culture. The results showed that the applied starter culture can be used for the production of fermented whey based beverage with satisfactory nutritional properties. Addition of milk was important not only in the nutritional quality of the resulting product, but also improved the taste, the homogeneity and stability. Analysis of the chemical composition of fermented whey based beverage and nutritional information about it indicates that the product is a good source of protein and calcium. Fermented beverage contained 8.07 log (CFU/mL), showed antioxidant activity of at least 38.1% and the titratable acidity of 28.2?SH corresponding to the acidity of the product in this category.

The area of functional beverages made from plant-based or non-dairy milk is one of the fastest-growing sectors in the world. The microalgae Chlorella vulgaris is a source of functional ingredients, with a large spectrum of healthy compounds, such as canthaxanthins, astaxanthins, peptides, and oleic acid. The study aimed to investigate the suitability of C. vulgaris biomass as a substrate for Lactobacillus fermentum and Lactobacillus rhamnosus development and fermentation in vegetal soy beverages and to evaluate the fermented product in terms of bacterial viability, antioxidant capacity, and in vitro bio-accessibility. During fermentation, a bacterial concentration of 8.74 log10 CFU/mL was found in the soy beverage with C. vulgaris and L. rhamnosus, and 8.71 log10 CFU/mL in beverage with C. vulgaris and L. fermentum. Polyphenol content and dietary antioxidant capacity significantly improved after fermentation soy drinks. On the other hand, through the digestibility of the beverages, the bacterial viability significantly decreased. To comprehend the components responsible for the efficient delivery of bacteria across the gastrointestinal tract, further investigation is required on probiotic encapsulation methods.

This work describes a new process for the production of beverages from spent coffee grounds (SCG), as well as the chemical and sensory profiles. The process consisted of the extraction of antioxidant phenolic compounds of SCG, followed by the fermentation of this extract supplemented with sucrose and fermented broth distillation. Thus, two fermented (10.4% and 10.0% of ethanol, by volume) and two distillated (38.1% and 40.2% of ethanol, by volume) beverages were obtained. A total of 45 and 59 volatile compounds (alcohols, esters, aldehydes, terpenes, lactones, pyrazines, norisoprenoids, volatile phenols and acids) identified and quantified by GC-MS characterized the aroma and flavor of the fermented and distilled beverages, respectively. Twenty sensory descriptors define the sensory profile of the two beverages which corroborated the pleasant smell and taste of coffee in the distillate beverage. Therefore, this work demonstrates that the fermented and distilled beverages obtained from spent coffee grounds have acceptable organoleptic qualities that make them suitable for human consumption.

Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2016.
This study focused on alcoholic fermented fruit beverages that were produced from various types of fruit, value addition and thus potentially increasing the diversity of commercially available fruit wines. Non-grape alcoholic fermented fruit beverages is a complex mixture of water, alcohol, and other components, that are either initially present in the fruit, or are formed during the fermentation process. The evaluation of wine and similar fermented products quality is important for manufacturers and consumers. The routine analysis of alcoholic fermented fruit beverages acts as an important tool that is useful for wine classification, quality control and sensory evaluation. Therefore, the aims of this study were (1) to measure methanol, ethanol, titratable acidity, objective colour, total soluble solids and sensory profile as a function of yeast strain and percentage pulp in order to adapt existing technologies toward producing new fermented fruit beverage products using plums, an under-utilized agricultural produce; and (2) to measure methanol, ethanol, titratable acidity, objective colour, total soluble solids and sensory profile as a function of yeast strain, pulp percentage and sugar levels in order to adapt existing technologies toward producing new fermented fruit beverages based on red and white wine styles, while applying the technology developed in the first part of the study using red-fleshed plums, blueberries and blackberries. The independent variables (ID) were yeast strains (1) Saccharomyces cerevisiae VIN13, (2) Saccharomyces cerevisiae NT116, and (3) Saccharomyces bayanus N96, with formulations containing percentage pulp concentrations at (40%, 50% and 60%). The dependent variables (DV) constituted key quality parameters for white and red wine style, namely methanol, ethanol, titratable acidity, objective colour, total soluble solids, pH and sensory profile were measured. The optimal combination of independent variables was ascertained and in terms of the overall consumer response, for the red-fleshed plum beverage sample treatment N 96, 60% pulp showed the highest preference amongst consumers. In terms of the other dependent variables, namely methanol, ethanol, titratable acidity, objective colour, total soluble solids, pH and sensory profiles of alcoholic fermented fruit beverages based on white and red wine styles. The processing conditions developed and applied in this study towards the development of alcoholic fermented beverages utilizing plums and selected berries demonstrated ways of improving the utilization of fruit commodities by developing niche products. Hence, the development of alcoholic fermented beverages utilizing (plums and selected berries) showed potential for micro agro-industries, as well as the impact on its potential role in employment creation and income generation.

Negli ultimi anni le molecole bioattive con attività antimicrobica come tossine killer, batteriocine e agenti antifungini sono state impiegate per ridurre o inibire la crescita e lo sviluppo di funghi, lieviti e batteri indesiderati in alternativa o in combinazione con i composti sintetici antimicrobici negli alimenti e nelle bevande fermentate. La presente ricerca riguarda il ruolo e la caratterizzazione di molecole bioattive prodotte da lieviti appartenenti alle specie Metschnikowia pulcherrima, Tetrapisispora phaffii, Kluyveromyces wickerhamii, Wickerhamomyces anomalus. Dopo la caratterizzazione dei composti bioattivi prodotti da questi lieviti e lo studio dell'interazione tra le molecole antimicrobiche naturali e i lieviti/ le muffe sensibili, abbiamo voluto valutare il loro possibile impiego per combattere microrganismi contaminanti nell’agricoltura biologica e nel settore vinicolo. Nella prima parte della tesi è stata valutata l’azione inibente di sette ceppi di M. pulcherrima nei confronti di lieviti enologici principalmente coinvolti nel processo di vinificazione come Pichia, Candida, Hanseniaspora, Kluyveromyces, Saccharomycodes, Torulaspora, Brettanomyces e Saccharomyces. Un’efficace azione antagonista dei ceppi di M. pulcherrima è stata osservata nei confronti di lieviti indesiderati appartenenti ai generi Pichia, Brettanomyces e Hanseniaspora, mentre tale attività antimicrobica non si evidenziava nei confronti di Saccharomyces cerevisiae. Il secondo argomento trattato ha riguardato l’isolamento del gene che codifica Kpkt, la tossina killer prodotta da Tetrapisispora phaffii che possiede un’ampia attività antimicrobica nei confronti di vari lieviti alterativi del vino. La distruzione del gene ha provocato una perdita completa del fenotipo killer confermando così che TpBgl2p esercita un'attività antimicrobica. Il risultato ottenuto è la base per valutare la possibilità di esplorare la produzione eterologa della proteina che potrebbe essere utilizzata in campo enologico per ridurre le contaminazioni nel vino in sostituzione della SO2. Nella terza parte della tesi, l’attenzione è stata focalizzata sul danno indotto dalle tossine Kwkt and Pikt, prodotte rispettivamente da Kluyveromyces wickerhamii e Wickerhamomyces anomalus, coinvolte nel biocontrollo dei lieviti spoilage Brettanomyces/ Dekkera in vinificazione. L’effetto delle micocine è stato comparato con quello dell’anidride solforosa, generalmente usata come composto sintetico antimicrobico negli alimenti e nelle bevande fermentate. I risultati hanno mostrato diversi meccanismi di controllo della crescita di B. bruxellensis tra le due tossine e tra le tossine killer e il biossido di zolfo, anche se l'attività antimicrobica di quest’ultimo è fortemente influenzata dal fattore pH. Nella quarta parte della tesi è stata valutata l'interazione tra diversi lieviti ad attività antimicrobica e alcuni funghi filamentosi che in genere colonizzano i frutti maturi. Preliminarmente è stato eseguito uno screening in piastra per valutare l’eventuale effetto inibente di 42 lieviti verso 5 muffe, che causano i principali danni in frutta e verdura durante il periodo di post-raccolta. In una seconda fase, dieci ceppi selezionati sono stati testati per la loro attività inibitoria efficace contro le muffe in test in vivo su uva, limoni, arance, fragole e ciliegie. I risultati indicano che, tra i ceppi saggiati la migliore e interessante attività antagonista nei confronti delle muffe testate, è stata mostrata da due ceppi appartenenti a Wickerhamomyces anomalus e Metschnikowia pulcherrima.
In recent years, the bioactive compounds with antimicrobial activity such as yeast killer toxins, bacteriocins and natural antifungal agents are employed to reduce or inhibit the growth and the development of undesired fungi, yeasts or bacteria. Their use was proposed in alternative or in combination to the addition of synthetic antimicrobial agent in food and fermented beverage. The present research focused on the antimicrobial role and the characterization of bioactive molecules produced by yeast strains belonging to Metschnikowia pulcherrima, Tetrapisispora phaffii, Kluyveromyces wickerhamii, Wickerhamomyces anomalus species. Following a characterization of the antimicrobial compounds produced by these yeasts and investigating on the interaction between natural antimicrobial molecules and sensitive yeasts/moulds, the present study focused the attention on their use to combat contaminating microorganisms in “organic” agriculture and in wine industry. In the first part of the present thesis seven different strains of M. pulcherrima were screened to evaluate the growth inhibition of the main oenological yeasts such as Pichia, Candida, Hanseniaspora, Kluyveromyces, Saccharomycodes, Torulaspora, Brettanomyces and Saccharomyces involved in winemaking process. The effective antagonistic actions of M. pulcherrima strains was showed on undesired wild spoilage yeasts, such as the Pichia, Brettanomyces and Hanseniaspora genera, while Saccharomyces cerevisiae was not affected by the antimicrobial action of M. pulcherrima. The objective of the second part of this study was the isolation of the gene encoding Kpkt, a killer toxin produced by Tetrapisispora phaffii. The gene disruption caused a complete loss of the killer phenotype thus confirming that TpBgl2p exerts an effective killer activity and that the gene is effectively involved in the expression of the zymocin. The result obtained gives the basis to explore the heterologous production of the protein that could be used as starter in enological field to reduce wine contamination. In the third part of the thesis, the attention was focused on the damage induced by Kwkt and Pikt killer proteins, produced by Kluyveromyces wickerhamii and Wickerhamomyces anomalus, involved in the biocontrol of Brettanomyces/ Dekkera spoilage yeast in the wine industry. The effect of mycocins was also compared with sulfur dioxide, generally used as antiseptic in food and beverage industries. The results showed different mechanisms of control of B. bruxellensis growth within the two mycocins. Different mechanisms of action were also found between killer toxins and sulfur dioxide that is strongly influenced by pH. In the fourth part of this work it was evaluated the interaction between several yeasts that exhibit antimicrobial activity and some filamentous fungi that generally colonize mature fruits. Preliminarily, a plate screening was performed to assess inhibitory effect of 42 yeasts against 5 moulds, main spoilage microorganisms in vegetables and fruits during postharvest. In a second step, ten selected strains were tested for their effective inhibitory activity against moulds in vivo assay on grapes, lemons, oranges, strawberries and cherries. Results indicated that the best antagonistic activity was exhibited by Wickerhamomyces anomalus and Metschnikowia pulcherrima species that produced a significant reduction of moulds.

Thesis (MTech (Food Technology))--Cape Technikon, 2004
Probiotic foods are intended to supply selected viable microorganisms, for example Lactobacillus acidophilus and Bifidobacterium, to consumers. These organisms, when consumed at the daily intake of 108 , provide benefits beyond basic nutrition. Probiotic (AB) foods generally include fermented dairy products such as yoghurts and cheeses, targeted at the upmarket consumer. However, due to technical problems associated with the foods and the organism, viable Bifidobacterium rarely occur in AB foods. The principle aims of this study were to develop a suitable delivery system for Bifidobacterium to the consumer, and to supply these living organisms in the affordable traditional fermented African beverages, amasi and mahewu. This would provide the benefits of probiotics to the rural African consumer, where malnutrition and gastrointestinal diseases occur. The organism selected for this study was Bifidobacterium lactis DSM 10140, commonly associated with AB starter cultures for yoghurts. The delivery system selected was microencapsulation of B. lactis using a mixture of the generally recognised as safe (GRAS) edible gums, gellan and xanthan. Supply vehicles for the microcapsules to the consumer were amasi and mahewu. Prior to microencapsulation, rheological studies were undertaken to determine whether the gellan-xanthan gum mix would provide a suitable support matrix for microencapsulated B. lactis. This was done using a Paar Physica MGR 300 rotational rheometer with a cone plate 50-2 measuring system. Results indicated that the hydrated gellan-xanthan gum mix behaved as a non-Newtonian material, and the flow curve fitted well to the Herschel-Bulkley model. This demonstrated that the gel was a relatively viscous material with solid properties. The average yield stress of the gel was 1.515 Pa, indicating that the gel was stable, and at lower stresses would behave as a solid. The gel mix would be disrupted by shear stresses associated with mastication and peristalsis. The minimum viscosity of the gel was constant at temperatures between 46°C - 61°C. It was concluded from these data that the gel was suitable for microencapsulation and that microcapsules should only be included in soft foods, which do not require chewing. Temperatures associated with microencapsulation, at minimum gel viscosities, were not lethal to B. lactis. Bifidobacterium lactis cells were incubated under anaerobic conditions (4% H2, 10% CO2, and 86% N2) at 37°C overnight in 250 ml Tryptone-Yeast-Glucose (TYG) broth, and grown to an 00600 0.9 - 1.1. Cells were harvested and washed for microencapsulation using centrifugation. Microencapsulation of the organism was done using a mono-axial extrusion technique together with a superposed airflow, by manually extruding the aqueous gum I cell mix through a 27.5 G bevelled needle, fitted on to a 10 ml syringe. The resultant microdroplets were hardened by free fall into 0.1 M CaCI2 solution. Microcapsules were separated from the CaCI2 solution by filtration through Whatman No.1 filter paper. All procedures were carried out in a laminar flow hood. Results indicated that the method of microencapsulation used in this study was successful. Using a concentrated inoculum of B. lactis, high numbers (lOglO 11-12 etu.g-1 ) of bacteria were incorporated into the microcapsules. Therefore the daily intake would be provided by 0.1 g microcapsules. The diameter and size distribution of microcapsules were determined by laser diffractometry. This showed a maximum microcapsule diameter of 2.22 mm with 50% (w/v) of the microcapsules having a diameter of < 0.637 mm. Although this represents a considerable size variation, this would not adversely affect mouthfeel of the beverages, as only 0.1 g microcapsules would be required to obtain at least 108 B. lactis in any volume of amasi or mahewu. To enumerate immobilised viable B. lactis, two techniques were compared. These involved the use of either a pestle and mortar, or high power ultrasound (HPUS) (20 kHz, 750 W). Results showed that HPUS was superior to the pestle and mortar technique. A short exposure (15 s) to HPUS disrupted the matrix releasing all entrapped etus, whereas when using the pestle and mortar xiii technique, cells remained partially entrapped in the gel. Therefore the pestle and mortar technique yielded lower cfu values than expected. The survival of microencapsulated B. lactis, in 1 M sodium phosphate buffer, was studied as a possible means of supply of microcapsules to industry for incorporation into foods. Microcapsules were stored in the buffer for 21 days at either 4°C or 22°C. Results showed that cell viability was not significantly reduced (p>0.05) at either temperature after 21 days. Hence this form of storage could be used to deliver viable immobilised B. lactis to the food industry. In order to assess the survival of immobilised B. lactis in the GIT, the microcapsules were incubated at 37°C over a period of 240 min in simulated gastric juice (SGJ) (pH 1.5). Viable counts were performed by sampling at regular intervals. A similar study was done in simulated bile and pancreatic juices (BPJ) (pH 6.5). In SGJ, it was demonstrated that there was a significant reduction (3 log cycles) (p<0.05) of free cells after 240 min. However, this trend was not noted for microencapsulated B. lactis. Therefore, the gellanxanthan gel matrix protected B. lactis from the lethal effect of SGJ. In BPJ, no significant difference (p>0.05) was noted for surviving fractions of both immobilised and free B. lactis. Commercial pasteurised amasi (pH 4.4) and mahewu (pH 3.5) were selected as the supply vehicles for the microencapsulated B. lactis. Known numbers of viable microencapsulated and free B. lactis cells were added to both beverages. For most samples, incubation was at either 4°C or 22°C for 21 days in the presence of atmospheric oxygen. In addition, free cells were incubated anaerobically at 22°C. As oxygen is limiting in the microcapsules, these were not incubated under anaerobic conditions. The survival I shelf-life studies of commercial amasi indicated no significant difference (p>0.05) in survival rate between immobilised and free B. lactis cells. The reduction noted for viable counts of immobilised or free B. lactis cells was approximately 1.5 log cycles. Even so, after 21 days viable immobilised B. lactis (1010 0.1 g'l microcapsules) remained in excess of the daily intake 108 , whereas in the free B. lactis cells, the viable count declined to 106 mr1 . Statistical analyses showed that temperature or oxygen presence had little effect on the survival of both immobilised or free B. lactis cells (p>O.05). In mahewu, decline in viability of cells was observed for most samples. However microencapsulation enhanced cell survival at both 4°C and 22°C when compared to free cells. The decrease in viable B. lactis free cells occurred more rapidly (3 log cycles) in mahewu, than in amasi, at both 4°C and 22°C. Throughout the shelf-life studies it was apparent that viable B. lactis cell numbers did not increase. This was advantageous as metabolites associated with B. lactis growth would have adversely altered the taste of both amasi and mahewu. Sensory evaluation of the traditional fermented African beverages, enriched with either viable immobilised or free B. lactis, was done in order to determine consumer response to the product. An analytically trained 12-member taste panel analysed the beverages for colour, texture, and taste. The triangle taste test procedure was used. No differences were detected with regard to texture, and colour of the fermented beverages containing immobilised B. lactis. However, in the fermented beverages containing free cells, a change in viscosity was noted. There was a significant difference (p