scholarly journals Influence of Storage Temperature and Packaging on Bacteria and Yeast Viability in a Plant-Based Fermented Food

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 302 ◽  
Author(s):  
Miriam Cabello-Olmo ◽  
María Oneca ◽  
Paloma Torre ◽  
Jesús Díaz ◽  
Ignacio Encio ◽  
...  

Optimization of food storage has become a central issue for food science and biotechnology, especially in the field of functional foods. The aim of this work was to investigate the influence of different storage strategies in a fermented food product (FFP) and further determine whether the regular storage (room temperature (RT) and standard packaging (SP)) could be refined. Eight experimental conditions (four different temperatures × two packaging) were simulated and changes in FFP’s microbial ecology (total bacteria, lactic acid bacteria (LAB), and yeasts) and physicochemical characteristics (pH and moisture content (MC)) were determined following 1, 3, 6, and 12 months. All conditions tested showed a decline in microbial content due to the effect of the temperature, 37 °C being the most detrimental condition, while −20 and 4 °C seemed to be better than RT in some parameters. Vacuum packaging (VP) only had a major effect on MC and we found that VP preserved greater MC values than SP at 3, 6, and 12 months. The correlation analysis revealed that total bacteria, LAB, and yeasts were positively associated, and also both pH and MC showed a correlation. According to our results and with the purpose to maintain the load of viable microorganisms, we observed that the best storage conditions should contemplate SP and freezing or cooling temperature during a period no longer than 3 months.

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1057
Author(s):  
Emília Alves ◽  
Epole N. Ntungwe ◽  
João Gregório ◽  
Luis M. Rodrigues ◽  
Catarina Pereira-Leite ◽  
...  

Kefir, a traditional fermented food, has numerous health benefits due to its unique chemical composition, which is reflected in its excellent nutritional value. Physicochemical and microbial composition of kefir obtained from fermented milk are influenced by the type of the milk, grain to milk ratio, time and temperature of fermentation, and storage conditions. It is crucial that kefir characteristics are maintained during storage since continuous metabolic activities of residual kefir microbiota may occur. This study aimed to examine the nutritional profile of kefir produced in traditional in use conditions by fermentation of ultra-high temperature pasteurized (UHT) semi-skimmed cow milk using argentinean kefir grains and compare the stability and nutritional compliance of freshly made and refrigerated kefir. Results indicate that kefir produced under home use conditions maintains the expected characteristics with respect to the physicochemical parameters and composition, both after fermentation and after refrigerated storage. This work further contributes to the characterization of this food product that is so widely consumed around the world by focusing on kefir that was produced in a typical household setting.


2016 ◽  
Vol 118 (3) ◽  
pp. 749-760 ◽  
Author(s):  
Rossella Di Monaco ◽  
Nicoletta Antonella Miele ◽  
Stefania Volpe ◽  
Paolo Masi ◽  
Silvana Cavella

Purpose – Temporal dominance of sensation (TDS) is a sensory method developed by Pineau et al. (2003) which studies the sequence of dominant sensations of a product during its consumption. TDS is believed to be more appropriate to explain consumer responses than static descriptive analysis due to its temporal element. The purpose of this paper is to define the temporal sensory profile of a new product: polenta stick. In particular, TDS method was used to measure the dominance of sensory attributes in polenta stick samples and dynamic consumer tests were performed in order to verify if the acceptability changed over time during sample consumption. Design/methodology/approach – Eight polenta sticks, different in terms of storage conditions, cooking procedures and serving temperatures, were analysed by means of TDS with 13 assessors. During two preliminary sessions, the attributes list, constituted by the nine most cited sensations, was generated. Five replications were carried out. In dynamic consumer tests, 50 subjects were asked to give their liking on a seven-category scale for the frozen samples, in different five moments during the evaluation. Findings – TDS results showed a significant effect of the experimental conditions on dominant attribute perception of polenta sticks. For the oven-cooked samples, more flavour attributes were perceived as dominant, whereas for the fried samples, the attributes crispness and oiliness overcame with a high panel dominance rate and for a long time. For the chilled samples, crispness had the highest panel dominance rate; whereas for the frozen samples, creaminess was the most dominant attribute. Consumer liking scores did not significantly change over time during consumption for all the samples. The fried samples received the highest liking scores, at both serving temperatures. Practical implications – The chosen sensory methods gave the authors important information about the real perception of the products during consumption. A lot of foodstuffs show several sensory properties that appear in different times during evaluation and/or consumption. These properties could affect overall liking so they should be taken into account. Originality/value – New dynamic sensory methods were used to characterize a new food product, i.e. polenta-based sticks. The procedure used to evaluate the liking by consumers was completely innovative, whereas the sensory method used to characterize the samples was recently developed. The new food product was developed as an aim of an Italian research project funded by MiSE (Ministero dello Sviluppo Economico) for the valorization of maize flour (MAISFOOD, Industria 2015).


2014 ◽  
Vol 3 (5) ◽  
pp. 8 ◽  
Author(s):  
Maria Lorena Luna-Guevara ◽  
Oscar Jimenez-Gonzalez ◽  
Juan Jose Luna-Guevara ◽  
Paola Hernandez-Carranza ◽  
Carlos Enrique Ochoa-Velasco

<p>Tomato is one of the most important crops at worldwide; however, much of the production is lost during the postharvest due to the inadequate storage conditions. The aim of this study was to evaluate the effects of different postharvest conditions on some quality and bioactive parameters of tomatoes. Tomatoes Roma VF variety were stored at three temperature (7, 22, and 37 °C) to evaluate some physicochemical characteristics (pH, total soluble solids, titratable acidity, color, and firmness) and bioactive compounds (vitamin C, lycopene, carotenoids, and antioxidant activity) during five days; time in which tomato change from physiological to edible maturity. The <em>a</em> color parameter increased significantly (p &lt; 0.05) at the storage temperature of 22 and 37 °C. The firmness was higher in tomato stored at 7 °C after 5 days, while at 37 °C the firmness decrease in 8%. Tomatoes stored at 22 °C showed a decrease of chlorophyll <em>a</em> and <em>b</em>, reaching the maximum lycopene (31.7 ± 1.5 mg/kg fresh weight) and carotenoids contents (118.7 ± 0.1 ?g/100 g fresh weight), while at 7 and 37 °C the chlorophyll <em>a</em> did not change during the storage. However, the vitamin C was higher in tomatoes stored at 7 and 37 °C. The antioxidant activity remains constant during the time of storage, regardless the temperature. The storage temperature of 22 °C not affected significantly (p &lt; 0.05) the color and firmness of tomatoes, at the same temperature, the bioactive compounds (carotenoid, vitamin C, and antioxidant activity) presented highly correlated with the developments of the red color.</p>


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Teresa Szczęsna ◽  
Ewa Waś ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Katarzyna Jaśkiewicz ◽  
...  

The aim of this study was to determine the influence of storage temperature and time on physicochemical parameters of starch syrups recommended for the winter feeding of bee colonies. The studies included commercially available three starch syrups and an inverted saccharose syrup that were stored at different temperatures: ca. 20 °C, 10–14 °C, and ca. 4 °C. Physicochemical parameters of fresh syrups (immediately after purchase) and syrups after 3, 6, 9, 12, 15, 18, 21, and 24 months of storage at the abovementioned temperatures were measured. It was observed that the rate of unfavorable changes in chemical composition of starch syrups and the inverted saccharose syrup, mainly the changes in the 5-hydroxymethylfurfural (HMF) content, depended on the type of a syrup and storage conditions (temperature, time). Properties of tested starch syrups intended for winter feeding of bees stored at ca. 20 °C maintained unchanged for up to 6 months, whereas the same syrups stored at lower temperatures (10–14 °C) maintained unchanged physicochemical parameters for about 12 months. In higher temperatures, the HMF content increased. To date, the influence of this compound on bees has not been thoroughly investigated.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Michael J. Allison ◽  
Jessica M. Round ◽  
Lauren C. Bergman ◽  
Ali Mirabzadeh ◽  
Heather Allen ◽  
...  

Abstract Objective Silica gel beads have promise as a non-toxic, cost-effective, portable method for storing environmental DNA (eDNA) immobilized on filter membranes. Consequently, many ecological surveys are turning to silica bead filter desiccation rather than ethanol preservation. However, no systematic evaluation of silica bead storage conditions or duration past 1 week has been published. The present study evaluates the quality of filter-immobilized eDNA desiccated with silica gel under different storage conditions for over a year using targeted quantitative real-time polymerase chain reaction (qPCR)-based assays. Results While the detection of relatively abundant eDNA target was stable over 15 months from either ethanol- or silica gel-preserved filters at − 20 and 4 °C, silica gel out-performed ethanol preservation at 23 °C by preventing a progressive decrease in eDNA sample quality. Silica gel filter desiccation preserved low abundance eDNA equally well up to 1 month regardless of storage temperature (18, 4, or − 20 °C). However only storage at − 20 °C prevented a noticeable decrease in detectability at 5 and 12 months. The results indicate that brief storage of eDNA filters with silica gel beads up to 1 month can be successfully accomplished at a range of temperatures. However, longer-term storage should be at − 20 °C to maximize sample integrity.


2014 ◽  
Vol 83 (10) ◽  
pp. S3-S8 ◽  
Author(s):  
Lenka Necidová ◽  
Šárka Bursová ◽  
Alena Skočková ◽  
Bohdana Janštová ◽  
Pavla Prachařová ◽  
...  

The aim of this study was to compare Bacillus cereus growth rates and diarrhoeal enterotoxin production in raw and pasteurized goat, sheep, and cow milk in terms of storage conditions. Milk samples were inoculated with B. cereus (CCM 2010), which produces diarrhoeal enterotoxins. Enterotoxin production was tested by ELISA (Enzyme-Linked Immunosorbent Assay), and the count of B. cereus was determined by the plate method. With raw cow milk, B. cereus growth and enterotoxin production can be completely suppressed; in raw goat and sheep milk, enterotoxin was produced at 22 °C. In pasteurized cow, goat, and sheep milk, the B. cereus count increased under all storage conditions, with more rapid growth being observed at 15 °C (sheep milk) and 22 °C (cow and goat milk). Enterotoxin presence was detected at 15 °C and 22 °C, and with pasteurized cow milk also at 8 °C. Our model experiments have determined that B. cereus multiplication and subsequent enterotoxin production depend on storage temperature and milk type.


2009 ◽  
Vol 75 (23) ◽  
pp. 7409-7416 ◽  
Author(s):  
Ana Cláudia N. F. Spinelli ◽  
Anderson S. Sant'Ana ◽  
Salatir Rodrigues-Junior ◽  
Pilar R. Massaguer

ABSTRACT The prevention of spoilage by Alicyclobacillus acidoterrestris is a current challenge for fruit juice and beverage industries worldwide due to the bacterium's acidothermophilic growth capability, heat resistance, and spoilage potential. This study examined the effect of storage temperature on A. acidoterrestris growth in hot-filled orange juice. The evolution of the A. acidoterrestris population was monitored under six different storage conditions after pasteurization (at 92°C for 10 s), maintenance at 85°C for 150 s, and cooling with water spray to 35°C in about 30 min and using two inoculum levels: <101 and 101 spores/ml. Final cooling and storage conditions were as follows: treatment 1, 30°C for the bottle cold point and storage at 35°C; treatment 2, 30°C for 48 h and storage at 35°C; treatment 3, 25°C for the bottle cold point and storage at 35°C; treatment 4, 25°C for 48 h and storage at 35°C; treatment 5, storage at 20°C (control); and treatment 6, filling and storage at 25°C. It was found that only in treatment 5 did the population remain inhibited during the 6 months of orange juice shelf life. By examining treatments 1 to 4, it was observed that A. acidoterrestris predicted growth parameters were significantly influenced (P < 0.05) either by inoculum level or cooling and storage conditions. The time required to reach a 104 CFU/ml population of A. acidoterrestris was considered to be an adequate parameter to indicate orange juice spoilage by A. acidoterrestris. Therefore, hot-filled orange juice should be stored at or below 20°C to avoid spoilage by this microorganism. This procedure can be considered a safe and inexpensive alternative to other treatments proposed earlier.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 355
Author(s):  
Arícia Possas ◽  
Olga María Bonilla-Luque ◽  
Antonio Valero

Cheeses are traditional products widely consumed throughout the world that have been frequently implicated in foodborne outbreaks. Predictive microbiology models are relevant tools to estimate microbial behavior in these products. The objective of this study was to conduct a review on the available modeling approaches developed in cheeses, and to identify the main microbial targets of concern and the factors affecting microbial behavior in these products. Listeria monocytogenes has been identified as the main hazard evaluated in modelling studies. The pH, aw, lactic acid concentration and temperature have been the main factors contemplated as independent variables in models. Other aspects such as the use of raw or pasteurized milk, starter cultures, and factors inherent to the contaminating pathogen have also been evaluated. In general, depending on the production process, storage conditions, and physicochemical characteristics, microorganisms can grow or die-off in cheeses. The classical two-step modeling has been the most common approach performed to develop predictive models. Other modeling approaches, including microbial interaction, growth boundary, response surface methodology, and neural networks, have also been performed. Validated models have been integrated into user-friendly software tools to be used to obtain estimates of microbial behavior in a quick and easy manner. Future studies should investigate the fate of other target bacterial pathogens, such as spore-forming bacteria, and the dynamic character of the production process of cheeses, among other aspects. The information compiled in this study helps to deepen the knowledge on the predictive microbiology field in the context of cheese production and storage.


1995 ◽  
Vol 50 (9) ◽  
pp. 864-870 ◽  
Author(s):  
P. Krajnik ◽  
R. M. Quint ◽  
S. Solar ◽  
N. Getoff ◽  
G. Sontag

AbstractThe formation of tyrosine isomers by γ-radiolysis of neutral aqueous phenylalanine solutions was found to be strongly dependent on oxygen concentration and temperature. Changing the dose rate did not influence the degradation process. In the presence of 0.25 x 10-3 mol dm-3 oxygen at room temperature the yields of o-tyrosine as well as of m- and p-tyrosine drop from G(o-Tyr) = 0.5 and G(m-Tyr) = G(p-Tyr) = 0.4 at a dose of 0.3 kGy to 0.18 and 0.16 at 2.5 kGy, respectively. In solutions containing 1.25 x 10-3 mol dm-3 oxygen the initial yields remain unchanged but decrease at 2.5 kGy only to G(o-Tyr) = 0.3 and G(m-Tyr) = G(p-Tyr) = 0.20. Under the latter reaction conditions also 3,4-dihydroxyphenylalanine was found.Samples irradiated in frozen state did not show remarkable radiolysis of phenylalanine and tyrosine formation. In the range between 5 and 20°C no essential influence of temperature on the phenylalanine radiolysis and tyrosine yields was observable. The obtained results are important for methods using the tyrosine yields as markers for the detection of irradiated food. Storage conditions and irradiation temperature play an essential role on radiation induced changes of food.


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