scholarly journals Changes of Quality of Minimally-Processed Pineapple (Ananas comosus, var. ‘Queen Victoria’) during Cold Storage: Fungi in the Leading Role

2020 ◽  
Vol 8 (2) ◽  
pp. 185 ◽  
Author(s):  
Charlène Leneveu-Jenvrin ◽  
Baptiste Quentin ◽  
Sophie Assemat ◽  
Mathilde Hoarau ◽  
Jean-Christophe Meile ◽  
...  
Keyword(s):  
Cold Storage ◽  
Microbiological Quality ◽  
Fungal Species ◽  
Ananas Comosus ◽  
Minimally Processed ◽  
Leading Role ◽  
Queen Victoria ◽  
Processing Step ◽  
Yeasts And Molds

Minimally-processed pineapple stored under refrigerated conditions is highly perishable. We aimed to characterize the evolution of physicochemical, sensory and microbiological quality during cold storage. Pineapple batches were sampled from several locations in Reunion Island and then minimally processed. In the processing step, the variability of firmness and counts of yeasts and molds were observed. Moreover, correlations between the sampling season and pH and b* color component, as well as between fungal population and b* parameter were observed. During storage, the visual aspect of pineapple cuts changed to brown and shiny, whereas olfactive descriptors shifted from fruity descriptors and fresh to fermented, alcoholic and milky. The values for pH, TA and TSS did not significantly vary according to storage time. A decrease in firmness and C* color parameter was observed. Yeast and mold counts were significantly higher after 7 days of storage. The diversity in yeasts and molds was mainly dependent on the considered batches observed from PCR-DGGE profiles. Fungal species were isolated from spoiled pineapple cuts. The implication of Penicilllium citrtrinum, Talaromyces amestolkiae, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, and Meyerozyma caribbica in the spoilage of minimally-processed pineapple cuts was further demonstrated.

scholarly journals Effect of cutting shapes and thicknesses on the quality of minimally processed pineapple (Ananas comosus) cv. 'Queen Victoria'

2011 ◽  
Vol 11 (48) ◽  
pp. 5525-5538
Author(s):  
M. S Danyen ◽  
◽  
N Boodia ◽  
A Ruggoo
Keyword(s):  
Interaction Effect ◽  
Significant Interaction ◽  
Ananas Comosus ◽  
Physical Factors ◽  
Minimally Processed ◽  
Significant Interaction Effect ◽  
Queen Victoria ◽  
Main Effect ◽  
Keeping Quality

Cutting shape and size are physical factors that influence the keeping quality of minimally processed fruits and vegetables. Since these factors have not been studied as determinants of the keeping quality of minimally processed pineapples (MPP) cv. ‘Queen Victoria’, this study was conducted. A 2 x 2 factorial treatment structure laid on a randomized block design (RBD) was used. The treatments, which were blocked by days, were combinations of two cutting shapes (slices and chunks) and two thicknesses (5 mm and 10 mm). Pineapples of 25 - 50% ripeness were minimally processed to give rise to the treatments, which were then vacuum-packed at 47.5 kPa in laminated Low Density Polyethylene (LDPE) vacuum bags and stored at 4 ± 10 C for 12 days. Quality changes were evaluated at three-day intervals over a storage period of 12 days. Translucency score was evaluated by comparison method against standard colour charts. Electrical conductivity of leachate (ECL), firmness and pH were measured instrumentally. Ascorbic acid (AA) content was determined by titration with dichlorophenolindophenol (DCPIP) dye. Yeasts and moulds counts (YMC) were also enumerated using the classical standard method. Data were analysed using analysis of variance (ANOVA), and sum of squares due to treatment were split into main effect cutting shape, main effect thickness and interaction effect. All the keeping quality attributes of the MPP were significantly affected by storage time (p<0.001). Cutting shape also significantly affected translucency score (p<0.01), firmness (p<0.01) and YMC (p<0.01). Slices were firmer and had the lowest translucency score and minimized fungal growth as opposed to chunks. No significant interaction effect (p>0.05) was observed between cutting shapes and thicknesses on translucency score, firmness and YMC of the MPP. However, a significant interaction effect was noted between these two variables on ECL (p<0.05) and AA content (p<0.001). A thickness of 10 mm exhibited lower translucency score, higher ECL, reduced firmness and lower AA losses. pH was not significantly affected (p>0.05) by cutting shapes and thicknesses. Ten-mm slices maintained all the above-stated quality parameters, except ECL and pH, when stored at 4 ± 10 C for 12 days.

Microbiological Quality of Commercial Tofu

1984 ◽  
Vol 47 (3) ◽  
pp. 177-181 ◽  
Author(s):  
T. G. REHBERGER ◽  
L. A. WILSON ◽  
B. A. GLATZ
Keyword(s):  
Microbiological Quality ◽  
Plate Count ◽  
Microbial Counts ◽  
Colony Forming Units ◽  
Low Levels ◽  
Microbial Groups ◽  
Yeasts And Molds ◽  
Processing Techniques

A study was done to investigate the microbiological quality of commercial tofu available in local retail outlets. A sampling method was first developed to obtain accurate and representative microbial counts of individual pieces of tofu. Plate count determination of total aerobic organisms, psychrotrophs, coliforms, sporeformers, yeasts and molds, and staphylococci were made on 60 tofu samples (representing three lots each of four different brands) obtained within 24 h after delivery to the retail store. In addition, for two brands that provided manufacturer's pull dates, the same microbial counts were obtained for samples stored in the laboratory at 10°C until the pull date. Of the tofu sampled immediately after purchase, 83% of the lots tested had total counts greater than 106 colony-forming units (CFU)/g and psychrotrophic counts greater than 104 CFU/g. In addition, 67% of the lots tested had confirmed coliform counts greater than 103 CFU/g. Very low levels (less than 10 CFU/g) of all other microbial groups tested for were found in the majority of lots. Samples held until the manufacturer's pull date contained higher total and psychrotrophic counts but lower or stable counts of other organisms compared with samples tested immediately after purchase. To improve the microbiological quality of tofu, processors need to reduce initial loads by improving sanitation and processing techniques, and retailers should provide more consistent and colder refrigerated storage.

Chemical and Microbiological Quality of Raw Milk Produced by Smallholder Farmers in Zimbabwe

1996 ◽  
Vol 59 (9) ◽  
pp. 984-987 ◽  
Author(s):  
A. N. MUTUKUMIRA ◽  
S. B. FERESU ◽  
J. A. NARVHUS ◽  
R. K. ABRAHAMSEN
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Smallholder Farmers ◽  
Microbiological Quality ◽  
Titratable Acidity ◽  
Raw Milk ◽  
Chemical Characteristics ◽  
Yeasts And Molds ◽  
Microbiological Analyses

Chemical and microbiological analyses were carried out on 10 samples of raw milk collected over 6 months from the Nharira/Lancashire Milk Collection Center. The milk center is run by smallholder farmers. The purpose of the study was to evaluate the quality of the raw milk delivered to the milk collection center. The average chemical characteristics of the milk were (%): titratable acidity expressed as lactic acid, 0.21; total protein, 3.19; fat, 3.52; total solids, 11.76; and solids not fat, 8.25; the pH varied from 6.15 to 6.65. There were large variations in the microbiological composition of the raw milk with total aerobic counts ranging from 6.2 × 103 to 7.8 × 107 CFU/ml, coli forms from 3.2 × 102 to 2.3 × 105, and lactic acid bacteria from less than 1 × 103 to 2.9 × 106 CFU/ml. Yeasts and molds were less than 100 CFU/ml in 7 of the 10 samples analyzed.

Microbiological Quality of Frozen Cream-Type Pies Sold in Canada

1983 ◽  
Vol 46 (1) ◽  
pp. 34-40 ◽  
Author(s):  
E. C. D. TODD ◽  
G. A. JARVIS ◽  
K. F. WEISS ◽  
G. W. RIEDEL ◽  
S. CHARBONNEAU
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Microbiological Quality ◽  
The United States ◽  
National Guidelines ◽  
E Coli ◽  
Yeasts And Molds

Ten types of frozen cream-type pies, manufactured in Canada and imported from the United States, were analyzed for aerobic colony counts, yeasts and molds, coliforms, Escherichia coli, Staphylococcus aureus and Salmonella. The variations in counts depended more on the manufacturer than on the type of pie and the ingredients used. Five of the 465 examined pies had an excess of 105 aerobic colony counts/g, whereas the median value for all the pies examined was between 102 and 103 CFU/g. E. coli and S. aureus were present in few pies, mainly made by one manufacturer, but there was no correlation between high aerobic colony counts and these organisms. Salmonella was not found in any of the pies. Percentage distributions of the estimated ‘population’ of pies available nationally at the time of the survey were statistically determined. These were then compared with suggested national guidelines in the form of a three-class acceptance plan based on United States surveys and desirable manufacturing practices. These indicate that pies should contain aerobic colony counts of &lt;50,000/g, yeast and mold counts of &lt;500/g, S. aureus counts of &lt;100/g, coliform counts of &lt;50/g, E. coli counts of &lt;10/g, and no Salmonella. Three of the six manufacturers would have had an estimated 5.4 to 32.6% of lots in excess of the guidelines at the time of the survey.

Minimally Processed Vegetable Salads: Microbial Quality Evaluation

2007 ◽  
Vol 70 (5) ◽  
pp. 1277-1280 ◽  
Author(s):  
HANS FRÖDER ◽  
CECÍLIA GERALDES MARTINS ◽  
KATIA LEANI OLIVEIRA de SOUZA ◽  
MARIZA LANDGRAF ◽  
BERNADETTE D. G. M. FRANCO ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Microbiological Quality ◽  
Positive Sample ◽  
Fecal Coliforms ◽  
Microbial Quality ◽  
Biochemical Tests ◽  
Minimally Processed ◽  
Increasing Demand ◽  
Minimally Processed Vegetables

The increasing demand for fresh fruits and vegetables and for convenience foods is causing an expansion of the market share for minimally processed vegetables. Among the more common pathogenic microorganisms that can be transmitted to humans by these products are Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella. The aim of this study was to evaluate the microbial quality of a selection of minimally processed vegetables. A total of 181 samples of minimally processed leafy salads were collected from retailers in the city of Sao Paulo, Brazil. Counts of total coliforms, fecal coliforms, Enterobacteriaceae, psychrotrophic microorganisms, and Salmonella were conducted for 133 samples. L. monocytogenes was assessed in 181 samples using the BAX System and by plating the enrichment broth onto Palcam and Oxford agars. Suspected Listeria colonies were submitted to classical biochemical tests. Populations of psychrotrophic microorganisms &gt;106 CFU/g were found in 51% of the 133 samples, and Enterobacteriaceae populations between 105 and 106 CFU/g were found in 42% of the samples. Fecal coliform concentrations higher than 102 CFU/g (Brazilian standard) were found in 97 (73%) of the samples, and Salmonella was detected in 4 (3%) of the samples. Two of the Salmonella-positive samples had &lt;102 CFU/g concentrations of fecal coliforms. L. monocytogenes was detected in only 1 (0.6%) of the 181 samples examined. This positive sample was simultaneously detected by both methods. The other Listeria species identified by plating were L. welshimeri (one sample of curly lettuce) and L. innocua (2 samples of watercress). The results indicate that minimally processed vegetables had poor microbiological quality, and these products could be a vehicle for pathogens such as Salmonella and L. monocytogenes.

scholarly journals Microbiological quality of minimally processed vegetables sold in Porto Alegre, Brazil

2007 ◽  
Vol 38 (4) ◽  
pp. 594-598 ◽  
Author(s):  
Silvia R. Pavan da Silva ◽  
Sylvia E. Frizzo Verdin ◽  
Dariane C. Pereira ◽  
Aline M. Schatkoski ◽  
Marilise B. Rott ◽  
...  
Keyword(s):  
Microbiological Quality ◽  
Porto Alegre ◽  
Minimally Processed ◽  
Minimally Processed Vegetables
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