scholarly journals Food Spoilage by Bacilli: Combined Effects of pH, aw and Storage Temperature on Spore Germination and Growth in Cultural Broth Added with Solutes and Organic Acids

2020 ◽  
pp. 49-55 ◽  
Author(s):  
Barbara Franceschini ◽  
Maria Paola Previdi ◽  
Irene Schianchi
Keyword(s):  
Acetic Acid ◽  
Sodium Chloride ◽  
Spore Germination ◽  
Storage Temperature ◽  
Organoleptic Characteristics ◽  
Effects Of Ph ◽  
Different Temperatures ◽  
Combined Action ◽  
Bacillus Spores ◽  
Favorable Conditions

Aims: The control of Bacillus spores plays an important role in quality assurance and safety of processed foods. Their growth can be avoided by either sterilization or pasteurization in combination with a lowering of pH (≤ 4.6) or water activity (aw < 0.90) or with the combined action of both parameters (spore germination inhibition). In some food products, the reduction of pH to values ​​lower than 4.6 or a thermal treatment of sterilization can lead to nutritional and organoleptic changes, that are not always satisfactory for the consumer. The aim of this work was to produce data for a range of spoilage bacilli at a variety of pH and aw values and to monitor the potential outgrowth of these spores when stored at different temperatures. This study focused on the influence of the type of acid or solute used.   Place and Duration of Study: Quality, Safety and Pre-Industrialization Area, Stazione Sperimentale per l’Industria delle Conserve Alimentari-SSICA, Parma, Italy between March 2018 and November 2019. Methodology: B. sublitilis, B. licheniformis, B. cereus spore’s growth was studied in broth under the following conditions: aw (0.90 to 0.93), temperature (6, 12 and 30°C) and pH (4.9 to 5.5). Selected water activities were reached by the addition of appropriate amount of sodium chloride, sucrose or glycerol; pH was adjusted to various values with lactic acid, acetic acid or citric acid. Results: A combination of aw 0.92, with glycerol or sodium chloride and pH 5.1 inhibits the germination of all strains spores. B. subtilis was the species able to grow in the less favorable conditions. Acetic acid proved the strongest antimicrobial action; sodium chloride resulted more effective in inhibiting growth when used in combination with acids tested. Conclusion: The results achieved can be useful for the food industry, identifying the conditions that could preserve the product by means of a less drastic heat treatment preserving as much as possible the natural organoleptic characteristics.

Changes in technological quality of frost damaged sugar beet during storage

2017 ◽  
pp. 471-475
Author(s):  
Aneta Antczak-Chrobot ◽  
Paulina Bak ◽  
Maciej Wojtczak
Keyword(s):  
Acetic Acid ◽  
Sugar Beet ◽  
High Performance ◽  
Storage Temperature ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Initial Stage ◽  
Different Temperatures ◽  
Technological Quality

Both healthy and frost-damaged sugar beet were stored at different temperatures: 4, 12 and 20°C. Samples of sugar beet not damaged by frost were taken from storage after 20, 40, 48, 70 and 100 days, while samples of frost-damaged sugar beet were taken for further analysis after 8, 20, 28 and 36 days of storage. The content of dextran, mannitol and organic acids (lactic and acetic) were determined in the collected samples. The content of dextran was determined by ICUMSA Method GS8-19 (2007); the mannitol content by ICUMSA Method GS8-26 (2011); and the acids content by high performance anion exchange chromatography (HPACE) with a conductivity detector. The results show that in healthy sugar beet regardless of the storage temperature dextran was not found and the content of mannitol, lactic and acetic acid only slightly increased to an amount that would not harm processing of these beets. On the contrary, in frost-damaged sugar beet, which thawed during the initial stage of storage, the amount of undesirable compounds increased rapidly to an unacceptable level for processing depending on the storage temperature. Only storage at the low temperature of 4°C was able to postpone the formation of dextran in frost-damaged beets for about 10 days.

Effect of Potassium Sorbate on the Microbiological Quality of Butter

1979 ◽  
Vol 42 (8) ◽  
pp. 656-657 ◽  
Author(s):  
AJAY KAUL ◽  
JASJIT SINGH ◽  
R. K. KUILA
Keyword(s):  
Sodium Chloride ◽  
Storage Temperature ◽  
Microbiological Quality ◽  
Inhibitory Effect ◽  
Potassium Sorbate ◽  
Mold Growth ◽  
Coliform Count ◽  
Different Temperatures

Butter samples treated with potassium sorbate and sodium chloride were analyzed weekly for bacteriological qualities after storage at different temperatures. Addition of 0.1% potassium sorbate and incorporation of 2% sodium chloride plus 0.1 percent potassium sorbate resulted in inhibition of mold growth in all the samples at the end of 4 weeks at 18 C and 5 C. However the effect of potassium sorbate alone was less pronounced, irrespective of storage temperature. As regards coliform count in control butter, it increased rapidly at 22 C, but decreased when butter was stored at 5 C or – 18 C. Addition of potassium sorbate to butter samples stored at 18 C reduced the coliform count to zero after 4 weeks. while butter with added potassium sorbate and sodium chloride showed a zero count after 1 week, indicating a cumulative inhibitory effect.

Revisiting Glycerol Esterification with Acetic Acid over Amberlyst-35 via Statistically Designed Experiments: Overcoming Transport Limitations

2019 ◽  
Author(s):  
Víctor Gabriel Baldovino Medrano ◽  
Karen V. Caballero ◽  
Hernando Guerrero-Amaya
Keyword(s):  
Acetic Acid ◽  
Active Sites ◽  
Batch Reactor ◽  
Catalyst Particle ◽  
Experimental Designs ◽  
Particle Sizes ◽  
Turnover Rates ◽  
Designed Experiments ◽  
Different Temperatures ◽  
Glycerol Esterification

Turnover rates for glycerol esterification with acetic acid over Amberlyst-35 were measured under different temperatures, reactants and active sites concentrations, and catalyst particle sizes. Data were collected in a batch reactor. Experiments were done following a sequence of factorial experimental designs.

scholarly journals Changes of Physicochemical Properties of Starch Syrups Recommended for Winter Feeding of Honeybees during Storage

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Teresa Szczęsna ◽  
Ewa Waś ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Katarzyna Jaśkiewicz ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physicochemical Properties ◽  
Physicochemical Parameters ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Different Temperatures ◽  
And Storage ◽  
Bee Colonies ◽  
Temperature Time ◽  
Winter Feeding

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.

scholarly journals Kinetics and Mechanism of the Change of the 4-Nitrobenzylthio-System into 4,4′-Diformylazoxybenzene in Alkaline Dioxane-Water Media

1985 ◽  
Vol 40 (11) ◽  
pp. 1128-1132
Author(s):  
Y. Riad ◽  
Adel N. Asaad ◽  
G.-A. S. Gohar ◽  
A. A. Abdallah
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Rate Constants ◽  
Main Product ◽  
Reaction Medium ◽  
Aqueous Dioxane ◽  
Proton Abstraction ◽  
First Order ◽  
Water Media ◽  
Different Temperatures

Sodium hydroxide reacts with α -(4-nitrobenzylthio)-acetic acid in aqueous-dioxane media to give 4,4'-diformylazoxybenzene as the main product besides 4,4'-dicarboxyazoxybenzene and a nitrone acid. This reaction was kinetically studied in presence of excess of alkali in different dioxane-water media at different temperatures. It started by a fast reversible a-proton abstraction step followed by two consecutive irreversible first-order steps forming two intermediates (α -hydroxy, 4-nitrosobenzylthio)-acetic acid and 4-nitrosobenzaldehyde. The latter underwent a Cannizzaro's reaction, the products of which changed in the reaction medium into 4,4'-diformylazoxybenzene and 4,4'-dicarboxyazoxybenzene. The rate constants and the thermodynamic parameters of the two consecutive steps were calculated and discussed. A mechanism was put forward for the formation of the nitrone acid.Other six 4-nitrobenzyl, aryl sulphides were qualitatively studied and they gave mainly 4,4'-diformylazoxybenzene beside 4,4'-dicarboxyazoxybenzene or its corresponding azo acid.

α-DEUTERIUM KINETIC ISOTOPE EFFECTS IN SOLVOLYSES OF endo-NORBORNYL p-BROMOBENZENESULFONATE

1965 ◽  
Vol 43 (8) ◽  
pp. 2254-2258 ◽  
Author(s):  
C. C. Lee ◽  
Edward W. C. Wong
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Aqueous Dioxane ◽  
Kinetic Isotope ◽  
Different Temperatures

endo-Norbornyl-2-d p-bromobenzenesulfonate was synthesized and the isotope effects, as measured by kH/kD, were determined over a range of temperatures for solvolyses in 30% water – 70% dioxane, acetic acid, and formic acid. Values of kH/kD are of the order of 1.20. The data appear to indicate slightly higher isotope effects as the solvents are changed from aqueous dioxane to acetic acid to formic acid, as well as somewhat higher isotope effects at lower temperatures. Possible mechanistic implications of these results are presented. Relative titrimetric acetolysis rates, kexo/kendo, at different temperatures, and enthalpies and entropies of activation for these acetolyses are evaluated and discussed.

Accelerated ripening of Dhakki dates by artificial means: ripening by acetic acid and sodium chloride

2005 ◽  
Vol 70 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Shahzada A. Saleem ◽  
Ahmad K. Baloch ◽  
Musa Kaleem Baloch ◽  
Waqar A. Baloch ◽  
Abdul Ghaffoor
Keyword(s):  
Acetic Acid ◽  
Sodium Chloride ◽  
Accelerated Ripening

PRODUCTION OF GRANULATED INSTANT KISSEL BASED ON WHEY AND VEGETABLE RAW MATERIALS

2020 ◽  
Author(s):  
А.Л. Майтаков ◽  
Л.Н. Берязева ◽  
Н.Т. Ветрова ◽  
К.Б. Плотников
Keyword(s):  
Storage Temperature ◽  
Raw Materials ◽  
Storage Period ◽  
Technical Documentation ◽  
Plant Raw Materials ◽  
Temperature Conditions ◽  
Aronia Melanocarpa ◽  
Organoleptic Characteristics ◽  
Local Plant ◽  
The Stability

Разработан новый быстрорастворимый продукт (кисель) с определенным фазовым составом и строением на основе молочной сыворотки и местного растительного сырья – черноплодной рябины (Aronia melanocarpa). Разработана модель технологии производства быстрорастворимого гранулированного продукта (кисель) на основе молочной сыворотки и черноплодной рябины. Исследована сохраняемость киселя в трех температурных режимах: 1-й (21 ± 1)°С; 2-й с низкой плюсовой температурой (5 ± 1)°С; 3-й с повышенной (39 ± 1)°С при влажности окружающей среды 80%. По окончании годичного исследования сохраняемости при температурных режимах (21 ± 1)°С и (5 ± 1)°С изменений в органолептических показателях продукта не наблюдали. Скорость растворения продукта при температурных условиях хранения (21 ± 1)°С и (5 ± 1)°С не изменялась на протяжении 9 мес. Установлено, что при хранении в условиях пониженных положительных температур 4–6°С и в режиме комнатной температуры (21 ± 1)°С исследуемый пищеконцентрат по окончании 6 мес. хранения не изменил свойств по показателям качества. Сроки испытания продукта превышали по длительности в 2 раза заданный срок хранения (коэффициент запаса). Результаты испытаний явились основанием для разработки технической документации на производство быстрорастворимых гранулированных плодово-ягодных киселей. A new fast – soluble product (kissel) with a certain phase composition and structure based on whey and local plant raw materials Aronia melanocarpa. A model of technology for the production of a rapidly soluble granular product (kissel) based on whey and Aronia melanocarpa has been developed. The stability of kissel in three temperature modes was studied: 1st (21 ± 1)°C; 2nd with a low plus temperature (5 ± 1)°C; the 3rd with the increased (39 ± 1)°C at 80% ambient humidity. At the end of a year-long study at temperature conditions (21 ± 1)°С and (5 ± 1)°С, no changes in the organoleptic characteristics of the product were observed. Dissolution rate of the product under storage temperature conditions (21 ± 1)°C and (5 ± 1)°C did not change for 9 months. It is established that when stored at low positive temperatures 4–6°C. With and at room temperature (21 ± 1)°C. At the end of 6 months of storage, the food concentrate under study did not change its properties in terms of quality. The product testing period was 2 times longer than the specified storage period. The test results were the basis for the development of technical documentation for the production of instant granulated fruit and berry kissel.

STORAGE TEMPERATURE AS A FACTOR OF FAT MIGRATION IN GLAZED SUGARY CONFECTIONERY PRODUCTS

1970 ◽  
pp. 78-80
Author(s):  
N. B. Kondratyev ◽  
Е. V. Kazantsev ◽  
O. S. Rudenko ◽  
N. А. Petrova ◽  
I. А. Belova
Keyword(s):  
Fatty Acids ◽  
Migration Rate ◽  
Unsaturated Fatty Acids ◽  
Storage Temperature ◽  
Polymorphic Form ◽  
Specific Rate ◽  
Confectionery Products ◽  
Different Temperatures ◽  
Physical And Chemical Quality ◽  
Physical And Chemical

The fat migration processes by changing the fatty acid composition of individual parts of glazed sweets with praline-type bodies (based on peanuts) during storage at different temperatures was studied. The main mechanism of mass transfer is considered to be the fat migration through the volume of products through the capillaries. The maximum migration rate of the liquid fat phase is at a storage temperature of 23-25 ° C in samples without transisomers of unsaturated fatty acids. Its reduction is possible with the introduction of 20-30% lauric acid into the fat fraction of products. The crystalline structure of the confectionery fats included in the candy fillings has a significant effect on the migration rate of the liquid fat phase into the glaze. The smallest one corresponded to fats in the β-polymorphic form with an admixture of no more than 3% crystals in the β'-polymorphic form. The specific rate of fat migration has been calculated taking into account the size of a glazed sweets model samples. When in storage temperature increases from 18 to 27 ˚С, it increased 1.7 times. The results of studies of changes in the composition of fatty acids of model samples individual parts of glazed sweets during storage at temperatures of 18 and 27 °C are presented. The proposed approach makes it possible to predict the fat migration processes rate. The comprehensive assessment methodology, which includes the determination of physical and chemical quality indicators during storage, the regularities of fat migration and microbiological changes, will justify the requirements for the technology parameters and the recipe composition of glazed sugary confectionery products with a given expiration date.

Sign in / Sign up

Export Citation Format

Share Document