scholarly journals Effects of Acidification and Preservatives on Microbial Growth during Storage of Orange Fleshed Sweet Potato Puree

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Joyce Ndunge Musyoka ◽  
George Ooko Abong' ◽  
Daniel Mahuga Mbogo ◽  
Richard Fuchs ◽  
Jan Low ◽  
...  
Keyword(s):  
Citric Acid ◽  
Sweet Potato ◽  
Sodium Benzoate ◽  
Microbial Growth ◽  
Challenge Test ◽  
Potassium Sorbate ◽  
Food Ingredient ◽  
Chemical Preservatives ◽  
Yeasts And Molds ◽  
Orange Fleshed Sweet Potato

Orange Fleshed Sweet Potato (OFSP) puree, a versatile food ingredient, is highly perishable limiting its use in resource constrained environments. It is therefore important to develop shelf-stable puree. A challenge test study was carried out to determine the effect of combinations of chemical preservatives and acidification on microbial growth in stored puree. Puree was prepared and treated as follows: control (A); 0.05% potassium sorbate+0.05% sodium benzoate+1% citric acid (B); 0.1% potassium sorbate+0.1% sodium benzoate+1% citric acid (C); 0.2% potassium sorbate+0.2% sodium benzoate+1% citric acid (D); 1% citric acid (E). Samples were inoculated with Escherichia coli and Staphylococcus aureus at levels of 5.2 x 109 cfu/100g and 1.5 x 109 cfu/100g, respectively, before being evaluated during storage for 10 weeks at prevailing ambient temperature (15-25°C) and refrigeration temperature (4°C). Total aerobic counts, yeasts, and molds were also evaluated. E. coli and S. aureus counts declined significantly (p<0.05) by 4 log cycles in all puree treatments except for control and puree with only citric acid. Total viable count, yeasts, and molds were completely inhibited except for puree with only citric acid. Combination of chemical preservatives and acidification is effective in inhibiting pathogens and spoilage microorganisms in sweet potato puree.

Microbial Growth and the Effects of Mild Acidification and Preservatives in Refrigerated Sweet Potato Puree†,‡

2008 ◽  
Vol 71 (3) ◽  
pp. 639-642 ◽  
Author(s):  
ILENYS M. PÉREZ-DÍAZ ◽  
VAN-DEN TRUONG ◽  
ASHLEE WEBBER ◽  
ROGER F. MCFEETERS
Keyword(s):  
Citric Acid ◽  
Sweet Potato ◽  
Microbial Growth ◽  
Microbial Contamination ◽  
Sorbic Acid ◽  
Potassium Sorbate ◽  
Bacterial Cells ◽  
Refrigerated Storage ◽  
Sweet Potatoes ◽  
Naturally Occurring

Refrigerated sweet potato puree is a convenient form of sweet potato that can be used as an ingredient in formulated foods. The microbiology of refrigerated sweet potato puree during storage for up to 5 weeks was evaluated. Because the puree was made by comminuting steam-cooked sweet potatoes before refrigeration, no naturally occurring vegetative bacterial cells were detected during a 4-week period of refrigerated storage at 4°C. However, if postprocessing microbial contamination of the puree were to occur, contaminating microorganisms such as Listeria monocytogenes could grow during refrigerated storage. The effects of acidification or the addition of potassium sorbate and sodium benzoate on a population of L. monocytogenes inoculated into refrigerated (4°C) sweet potato puree were determined. Inoculation of the refrigerated puree with L. monocytogenes at 106 CFU/ml resulted in a 3-log increase after 3 weeks storage of nonsupplemented puree. Supplementation of the sweet potato puree with 0.06% (wt/vol) sorbic acid or benzoic acid plus mild acidification of the sweet potato puree with citric acid to pH 4.2 prevented growth of L. monocytogenes during storage at 4°C.

scholarly journals Effect of Addition of Citric Acid and Sodium Benzoate on pH and Microbial Profile of Soymilk

2020 ◽  
pp. 21-31 ◽  
Author(s):  
Johnpaul I. Agbaka ◽  
Charles N. Ishiwu ◽  
Ajibola N. Ibrahim
Keyword(s):  
Citric Acid ◽  
Sodium Benzoate ◽  
Food Systems ◽  
Tap Water ◽  
Control Sample ◽  
Storage Period ◽  
Ambient Conditions ◽  
Alternative Source ◽  
Microbial Profile ◽  
Chemical Preservatives

Aim: To study the synergistic effect of chemical preservatives on the keeping quality of soymilk. Study Design: Ten soymilk samples were prepared and treated with different concentrations of citric acid and sodium benzoate and stored at ambient conditions. Place and duration of Study: The present study was conducted at the Department of Food Science and Technology, Nnamdi Azikiwe University, Awka between March 2015 and June 2016 Methodology: Ten (10) soymilk samples were prepared. Soybean seeds (2 kg) that are free of dirt and stones were weighed and steeped in 4 L of tap water, a 12 h steeping regime was adopted. Each soymilk sample was formulated by adding different concentrations of sodium benzoate and citric acid, while the control sample had no treatment. All soymilk samples were then boiled at 75oC for 15 minutes and stored in storage bottles. Standard microbiological techniques were employed in the isolation and enumeration of potential spoilage organisms in soymilk samples. pH analysis was conducted throughout the storage period. Results: There was a decrease in pH of all soymilk samples with increasing storage time. pH at day 0 ranged between 6.2 to 7.2. Isolated bacteria in 10 soymilk samples included Streptococcus sp., Pseudomonas sp., Proteus sp., Bacillus spp., Staphylococcus aureus, Klebsiella sp., Escherichia coli, and Enterobacter species. However, results obtained showed that soymilk could keep up to 7 days at ambient temperature, encouraging the use of citric acid and sodium benzoate as chemical preservatives. Conclusion: In the present study, preservation of soymilk samples from a combination of citric acid and sodium benzoate which are chemical preservatives was found to be more effective than several organic preservatives. Hence, they represent an alternative source of chemical antimicrobial substances for use in food systems to prevent the growth of food borne microorganisms and extend the shelf-life of processed food.

Effect of Quinic Acid on the Growth of Some Wild Yeasts and Molds

1985 ◽  
Vol 48 (4) ◽  
pp. 327-329 ◽  
Author(s):  
HEIKKI KALLIO ◽  
SEIJA AHTONEN ◽  
SEPPO S. SARIMO
Keyword(s):  
Sodium Benzoate ◽  
Quinic Acid ◽  
Inhibitory Effect ◽  
Potassium Sorbate ◽  
Lag Phase ◽  
Antifungal Effect ◽  
Hansenula Anomala ◽  
Wild Yeasts ◽  
Yeasts And Molds ◽  
Byssochlamys Fulva

The effect of quinic acid on growth of wild yeasts (Hansenula anomala, Saccharomyces cerevisiae and Schizosaccharomyces pombe) and molds (Aspergillus amstelodami, Botrytis cinerea and Byssochlamys fulva) was investigated. Quinic acid alone had no antifungal effect on the microbes tested. Generation time of the yeasts remained unaltered in the presence of up to 1% quinic acid, whereas growth of the molds was accelerated. No synergistic effect of quinic acid together with potassium sorbate or sodium benzoate was observed. Quinic acid was antagonistic to the antifungal effects of both potassium sorbate and sodium benzoate on molds. In co-use with sorbate and benzoate, quinic acid shortened the lag phase of the growth of molds. The inhibitory effect of 0.01 to 0.02% sodium benzoate was almost completely eliminated by adding 1% quinic acid.

Effect of Selected Generally Recognized as Safe Preservative Sprays on Growth of Listeria monocytogenes on Chicken Luncheon Meat

2002 ◽  
Vol 65 (5) ◽  
pp. 794-798 ◽  
Author(s):  
MAHBUB ISLAM ◽  
JINRU CHEN ◽  
MICHAEL P. DOYLE ◽  
MANJEET CHINNAN
Keyword(s):  
Listeria Monocytogenes ◽  
Sodium Benzoate ◽  
Untreated Control ◽  
Potassium Sorbate ◽  
Sodium Propionate ◽  
Luncheon Meat ◽  
Chemical Preservatives ◽  
Sodium Diacetate

The ability of selected generally recognized as safe (GRAS) chemical preservatives to reduce populations or inhibit growth of Listeria monocytogenes on chicken luncheon meat was evaluated. Slices of luncheon meat were treated by evenly spraying onto their surfaces 0.2 ml of a solution of one of four preservatives (sodium benzoate, sodium propionate, potassium sorbate, and sodium diacetate) at one of three different concentrations (15, 20, or 25% [wt/vol]). Each slice was then surface inoculated with a five-strain mixture of 105 CFU of L. monocytogenes per ml, held at 4, 13, or 22°C, and assayed for L. monocytogenes immediately after inoculation and at 3, 7, 10, and 14 days of storage. Initial reductions of L. monocytogenes populations ranged from 0.78 to 1.32 log10 CFU g−1 at day 0 for sodium benzoate– or sodium diacetate–treated meat, whereas reductions for the sodium propionate or potassium sorbate treatments were only 0.14 to 0.36 log10 CFU g−1. After 14 days of storage at 4°C, L. monocytogenes populations on all treated slices were 1.5 to 3 log10 CFU g−1 less than on the untreated slices. At 13°C and after 14 days of storage, L. monocytogenes populations were 3.5 and 5.2 log10 CFU g−1 less on luncheon meat slices treated with 25% sodium benzoate or 25% sodium diacetate, respectively, and ca. 2 log10 CFU g−1 less when treated with 25% sodium propionate or 25% potassium sorbate than on untreated control slices. Only sodium diacetate was highly inhibitory to L. monocytogenes on meat slices held at 22°C for 7 days or longer. Untreated luncheon meat held at 22°C was visibly spoiled within 10 days, whereas there was no evidence of visible spoilage on any treated luncheon meat at 14 days of storage.

Chemical Preservatives Action on Microbial Growth in a Model System of Refrigerated Prepeeled Potatoes

1993 ◽  
Vol 56 (9) ◽  
pp. 801-807 ◽  
Author(s):  
L. GIANNUZZI ◽  
N. E. ZARITZKY
Keyword(s):  
Ascorbic Acid ◽  
Citric Acid ◽  
Storage Time ◽  
Microbial Growth ◽  
Total Concentration ◽  
Inhibitory Effect ◽  
Model System ◽  
Sodium Bisulfite ◽  
Chemical Preservatives ◽  
Aerobic And Anaerobic

The effect of different concentrations of citric acid and ascorbic acid (applied individually or in mixture's) on microbial growth in potato homogenate was analyzed and compared to the sodium bisulfite action during storage at 4°C in low gaseous permeability films. These experiments allowed one to simulate the behavior of prepeeled potatoes but with a known amount of added preservative to evaluate additive or synergic effects. Total viable microorganisms, Enterobacteriaceae, Pseudomonas sp., Lactobacillus sp., molds, yeasts, Clostridium sulfite reducers, psychrotropic microorganisms, and aerobic and anaerobic viable spores were analyzed during storage time. Inhibition indexes produced by the tested preservatives were calculated for the different microorganisms. Sodium bisulfite solutions (100 ppm) had no inhibitory effect. Concentrations of 3,500 ppm citric acid and 10,000 ppm ascorbic acid showed antimicrobial action as well as mixtures of citric acid/ascorbic acid of the following compositions (in terms of total acids concentration): 2,700/2,000, 3,500/2,000, and 2,700/3,000 ppm. A higher effect on Enterobacteriaceae was observed in comparison with other microorganisms. The apparent synergic effect of these acids when they were applied together was demonstrated to be actually an additive effect when concentrations of undissociated acid in the mixtures were considered instead of total concentration.

scholarly journals Sensory Attributes of Composite Breads from Shelf Storable Orange-Fleshed Sweetpotato Puree

2018 ◽  
Vol 3 (1) ◽  
pp. 459-465 ◽  
Author(s):  
Tawanda Muzhingi ◽  
Joshua Ombaka Owade ◽  
George Ooko Abong ◽  
Michael Wandayi Okoth ◽  
Simon Heck ◽  
...  
Keyword(s):  
Citric Acid ◽  
Sodium Benzoate ◽  
Beta Carotene ◽  
Sensory Profile ◽  
Cold Chain ◽  
Potassium Sorbate ◽  
White Bread ◽  
Technological Advances ◽  
Composite Flours ◽  
Sensory Qualities

Abstract Technological advances in baking have enabled the use of bread as a food vehicle for various nutrients through use of composite flours. Orange-fleshed sweetpotato (OFSP) puree subjected to cold chain storage has been used to enrich bread with beta-carotene. However, this has proven expensive and inconsistent in supply of puree. This study sought to develop shelf-storable OFSP puree bread with similar sensory qualities to fresh OFSP puree bread. Bread in which two treatments of shelf-storable OFSP puree (treatments 1 and 2 with 0.5% potassium sorbate+0.5% sodium benzoate+1% citric acid and 0.2% potassium sorbate+0.2% sodium benzoate+1%citric acid respectively) were incorporated at 30% and 40% and were subjected to descriptive sensory analysis with white and fresh puree breads as controls. The results indicate that both the 40% and 30% wheat substitution with either treatment 1 or 2 OFSP puree bread are acceptable to the consumers, p<0.05. The saltiness, smoothness and crumb color scores for shelfstorable OFSP puree bread were similar to those of fresh puree bread but were significantly (p<0.05) higher than that of white bread. Shelf-storable OFSP puree bread had similar sensory profile to fresh OFSP puree bread thus can be exploited as an alternative to fresh puree bread.

scholarly journals A Study on Watermelon (Citrullus Lanatus) Juice Preserved with Chemical Preservatives at Refrigeration Temperature

2013 ◽  
Vol 5 (2) ◽  
pp. 23-28 ◽  
Author(s):  
MK Alam ◽  
MM Hoque ◽  
S Morshed ◽  
SMS Shahriar ◽  
A Begum
Keyword(s):  
Ascorbic Acid ◽  
Natural Resources ◽  
Sodium Benzoate ◽  
Nutritional Quality ◽  
Citrullus Lanatus ◽  
Ascorbic Acid Content ◽  
Potassium Sorbate ◽  
Watermelon Juice ◽  
Juice Sample ◽  
Chemical Preservatives

This study was done to analyse the effect of chemical preservatives on watermelon juice. The samples were; pasteurized watermelon juice (T1), pasteurized watermelon juice +20% sucrose (T2), pasteurized watermelon juice +0.1% sodium benzoate (T3), pasteurized watermelon juice +20% sucrose +0.1% sodium benzoate (T4), pasteurized watermelon juice +0.1% potassium sorbate (T5), pasteurized watermelon juice +20% sucrose+0.1% potassium sorbate (T6), pasteurized watermelon juice +0.05% sodium benzoate +0.05% potassium sorbate (T7), pasteurized watermelon juice +20% sucrose +0.05% sodium benzoate +0.05% potassium sorbate (T8), pasteurized watermelon juice +0.1% sodium benzoate +0.1% potassium sorbate (T9), pasteurized watermelon juice +20% sucrose +0.1% sodium benzoate +0.1% potassium sorbate (T10). The samples were stored at 4 - 15°C for three months. T1 and T2 were rejected soon due to spoilage. Minimum ascorbic acid content was reduced in T10 (23.85%), while maximum in T4 (44.44%). Minimum acidity was increased in T10 (50.00%), while maximum in T1 (107.69%). Treatments T10, T9 T8 and T6 were found most acceptable in maintaining the sensory characteristics compared to others during storage. Among all the treated juice sample T10 was most effective in maintaining the sensory and nutritional quality during storage.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14597 J. Environ. Sci. & Natural Resources, 5(2): 23-28 2012

scholarly journals Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Derick Nyabera Malavi ◽  
Tawanda Muzhingi ◽  
George Ooko Abong’
Keyword(s):  
Sweet Potato ◽  
Microbial Contamination ◽  
Processing Plant ◽  
Microbial Quality ◽  
Limited Information ◽  
Microbiological Methods ◽  
Good Manufacturing Practices ◽  
The Status ◽  
Yeasts And Molds ◽  
Orange Fleshed Sweet Potato

Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly (P<0.05) reduced microbial load in OFSP cooked roots but the counts significantly (P<0.05) increased in the puree due to postprocessing contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, andE. coliandS. aureuscounts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log10cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree.

scholarly journals Improvement of injera shelf life through the use of chemical preservatives

2012 ◽  
Vol 12 (53) ◽  
pp. 6409-6423
Author(s):  
Z Ashagrie ◽  
◽  
D Abate
Keyword(s):  
Aspergillus Niger ◽  
Benzoic Acid ◽  
Shelf Life ◽  
Sodium Benzoate ◽  
Energy Utilization ◽  
Eragrostis Tef ◽  
Potassium Sorbate ◽  
Significant Implication ◽  
Calcium Propionate ◽  
Chemical Preservatives

Mould spoilage is a serious problem that affect s the shelf life of injera , the staple Ethiopian fermented bread. Injera is made from teff ( Eragrostis tef ) but other cereals may also be used in combination with teff. About two- third of Ethiopian diet consists of injera and it accounts for about two -third s of the daily protein intake of the Ethiopian population. I njera has a high nutritional value, as it is rich in calcium and iron. Unfortunately, injera has a shelf life of only 3-4 days essentially due to mould spoilage. The use of weak organic acid as preservative is allowed in acidic foods, primarily as mould inhibitor s. In this study, the effect of chemical preservatives such as benzoic acid, sodium benzoate, potassium sorbate and calcium propionate were investigated to prolong shelf life of injera . The preservatives were added immediately before baking at the concentration of 0.1% of benzoic acid, 0.1% sodium benzoate, 0.2% of potassium sorbate, 0.3% of calcium propionate and 0.2% blend of the four as recommended by Food and Drug Administration of USA. Three fungal species: Aspergillus niger , Penicillium sp and Rhizopus sp were found to be responsible for injera spoilage. Penicillium and Rhizopus were more dominant at storage temperature of between 16- 20 0 C, while Aspergillus niger was found to be more dominant at higher temperature of 25 -32 0 C. Injera samples had a pH and moisture content between 3.38- 3.45 and 62- 65%, respectively. Anti -fungal activities of the preservatives investigated significantly prolonged the shelf life of injera for up to12 days. It was found out that the effectiveness of preservation was ranked as sodium benzoate>benzoic acid>potassium sorbate>blend>calcium propionate showing that benzoate and benzoic acid are the most effective. The outcome of the research has a significant implication in food security, energy utilization and a significant reduction in the amount of time used by women to produce injera

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