Baker's Yeast Quality Evaluation for Repacking and Storage under ...

More documents

Recommendations

Info

Journal of Applied and Industrial Sciences, 2013, 1 (2): 6-15, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE)leavening ability after storage. The suggestion in this work isto consider the values of specific loaf volumes expected fromgood quality yeast are ranging between 3.5 and 4.8cc/gr.13Fluted pumpkin seed flour, when substituted up to 20% levelin bread making give acceptable loaf volume quality 1.75-2.80cm [41]Table (9). Specific Volume of the Loaves Containing Baker's Yeast Samples A, B, C, A-1, B-1 and C-1 stored for 14 weekStorageduration(week)Samples (cc/g)A A-1 B B-1 C C-11 4.71 4.75 4.61 4.64 4.81 4.832 4.52 4.62 4.50 4.49 4.57 4.683 4.36 4.47 4.29 4.31 4.42 4.524 4.14 4.23 4.01 4.13 4.19 4.385 3.83 4.12 3.81 4.05 3.92 4.286 3.68 4.04 3.61 3.93 3.74 4.157 3.44 3.98 3.35 3.82 3.48 4.078 3.21 3.90 3.17 3.72 3.35 3.979 3.19 3.81 3.10 3.61 3.29 3.6510 3.04 3.67 2.98 3.44 3.11 3.6111 2.82 3.36 2.71 3.21 2.87 3.4712 2.71 3.17 2.62 2.95 2.78 3.2813 2.48 3.01 2.41 2.82 2.54 3.1214 2.26 2.80 1.15 2.69 2.36 2.97Where: A, B, C.: yeast samples stored at room temperature (30-35°C) and A-1, B-1 And C-1: yeast samples stored inrefrigerator (7-10°C)During dough fermentation gluten maturation occurs,promoting extensibility and gas retention. These characteristicsprovide volume, texture, aroma, taste and colour to the doughand bread [8]. Therefore, dough quality is fundamental toobtain high quality bread. Patents on baker’s yeast withimproved characteristics such as aromatic or nutritiveproperties confirms recent interest for a very wide range oftailored –made yeast-based ingredients for bakery application[5]. At zero time of the storage, both external and internalcharacteristics of the bread, made with the yeast samples, wereevaluated. The results presented in Table (10), show highlyacceptable organoleptic quality of bread. In various storagetimes, the bread sensory evaluation results showed that, thecolor of the crumb was found stable as light yellow colour,whereas crust color, texture, taste and aroma were significantly(at P< 0.05 level) decreased with the time. It can be concludedthat bread with improved sensory characteristics can beobtained by using yeast with good leavening and flavourformation abilities. Salt-stressed Backer’s yeast made thebread softener and significantly improved sensory propertiesfor aroma, taste and overall acceptability [42].Questionnaire results were presented in Table (11).Hundred percent of all groceries are not selling compressedyeast or any Sudanese made yeast, while 100% and 20% ofsmall and large groceries, respectively sell the baker’s yeast inrepacked polyethylene plastic bags. More than 80% of theshopkeepers in large and small groceries had no idea about thebaker’s yeast, whether it is a living microorganism or not.They deal with baker’s yeast as a type of baking power. It wasnoticed that there is no information on the labels of the factorypacked yeast telling the sellers how to handle or store theyeast. In addition, there is no restriction given to them to avoidselling part of the factory-sealed packages
Journal of Applied and Industrial Sciences, 2013, 1 (2): 6-15, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE)Table (10) Organoleptic Assay of Bread Containing the Yeast Samples14Parameter Sample Crust Colour Crumb Colour Texture Taste AROMA OverallAcceptanceSample A B.S 4.7 a 4.4 a 4.3 a 4.7 a 4.2 a 4.3 aSample B B.S 4.2 a 4.6 a 4.3 a 4.6 a 4.4 a 4.7 aSample C B.S 4.5 a 4.5 a 4.7 a 4.7 a 4.4 a 4.7 aSample A I.S 1.8 b 4.2 a 1.2 c 1.8 b 1.2 c 1.1 cSample B I.S 2.1 b 4.3 a 1.3 c 1.5 c 1.5 b 1.1 cSample C I.S 1.6 c 4.1 a 1.2 c 1.7 c 1.9 b 1.3 cSample A-1/ I.S. 2.4 b 4.5 a 1.9 b 1.4 c 2.0 b 1.3 cSample B-1/ I.S. 3.1 b 4.2 a 2.0 b 1.6 c 2.1 b 1.2 cSample C-1/ I.S. 2.5 b 4.4 a 1.8 b 1.5 c 2.1 b 1.5 cMeans scores with the superscript letters are not significantly different at P>0.05 level.Score obtained indicated the following: 5 = Excellent. 4 = Very good. 3 =good. 2 = fair. 1 = Not accepted.Where: B.S: Sample of bread containing yeasts before storage and I.S: Samples of bread containing yeasts during storage.Table (11) Results of Questionnaire Made About Baker's Yeast Selling in Khartoum North AreaDescription Small Groceries (%) Large Groceries (%)Selling dry instant yeast 90 00Selling compressed yeast 00 00Selling locally made yeast 00 00Selling saf- instant yeast strain 90 100Selling mauripan yeast strain 20 70Selling fermipan yeast strain 10 20Selling other strains 10 40Repacking yeast in small bags 100 20Idea about Sudanese factory 20 10Idea about yeast is a livingmicroorganism (correct)2010IV. CONCLUSIONSThe Following conclusions were drawn from this study:1. All baker ’ s yeast samples tested were originally ofgood quality.2. The practice of repackaging of yeasts in smallamounts caused a depression in bread volumes,specific loaf volumes and sensory evaluation scoresof the bread.3. Storing repacked packages at room temperature wasfound to affect the quality of the yeasts samplesnegatively. This effect was also noticed in thesamples stored in the refrigerator but quite slowly.4. The practice of repacking in plastic bags and badstorage of the yeasts contribute to bad quality breadproduction.5. The bad quality of bread found in the markets may bedue to using baker's yeast stored in inept conditions.V. REFERENCES[1] Ministry of commerce.(1993) Sudanese Yeast and FermentationFactory, Al-Hassahesa; Personal communication.[2]. Hamad, S. H. (1989). Screening of Yeast Associated with Foodfrom the Sudan and their possible Application for Single Cell Proteinand Ethanol Production. Ph. Dissertation, Sudan, Berlin.[3] Lodder, J.; Sloaff, W. C. H. and Kreger. Van, R. I. (1956). Theclassification of yeast. In ''The chemistry and Biology of yeast''. (A.H. Cook edit.). 1-57. Academic Press Inc.Publishers, New York.[4] Rose, A. H. and Harrison, J. S. (1969). “The Yeast.” AcademicPress Inc. London.[5] Gèlinas, P (2009). Inventions on baker’s yeast strains andspecially ingradients. Recent Pat. Food Nutr. Agric., Vol (1), pp,104-132.[6] Yerushaml. L. and volesky, B. (1981). ExperimentalBioenergetics of Saccharomyces cerevisiae in Respiration andFermentation. Biotech and Bioeng., XXIII : 2373-2390''.[7] Jay, J. M. (1992). Modern food Microbiology. Fourth edition.Published by Van Vostrant Reinhold, New York.[8] Calvel, R.; Wurtz, R. L.; and MacGuine, J. J. (2001). “The Tasteof Bread.” Aspen, MD (2001).[9] Pejin, D. J; Grujic, O. S; Pejin, J. D and Kocic-Tanackov, S. D(2009). Effect of yeast storage temperature and flour composition onfermentative activities of backer’s yeast. Zbornik Matice srpske zaprirodne nauke (116) 305-313.[10] Loveday, S. M; Huang, V. T; Reid, D. S and Winger, R. G(2012). Water dynamics in fresh and frozen yeasted dough. Crit. Rev.Food Sci. Nutr, Vol 52 (5), pp 390-409.
Page 3 and 4: GenusShapeSporeformingMotilitytestO
Page 5 and 6: Journal of Applied and Industrial S
Page 7: Deterioration(%)Journal of Applied

Baker's Yeast Quality Evaluation for Repacking and Storage under ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?