Detection of Guaiacol Produced by Alicyclobacillus acidoterrestris in Apple Juice by Sensory and Chromatographic Analyses, and Comparison with Spore and Vegetative Cell Populations

2000 ◽  
Vol 63 (11) ◽  
pp. 1517-1522 ◽  
Author(s):  
RACHEL V. ORR ◽  
ROBERT L. SHEWFELT ◽  
C. J. HUANG ◽  
SEBHAT TEFERA ◽  
LARRY R. BEUCHAT
Keyword(s):  
Apple Juice ◽  
Fruit Juice ◽  
Storage Period ◽  
Storage Conditions ◽  
Sensory Panel ◽  
Alicyclobacillus Acidoterrestris ◽  
Concentration Method ◽  
Processing And Storage ◽  
And Storage ◽  
Sampling Times

Spoilage of fruit juice by Alicyclobacillus acidoterrestris is characterized by a distinct medicinal or antiseptic off odor attributed to guaiacol, a metabolic by product of the bacterium. Detection of low populations of A. acidoterrestris that would precede sensory detection of guaiacol would enable juice processors to select appropriate processing and storage conditions that would minimize or eliminate spoilage. The objective of this study was to determine the recognition threshold of guaiacol in apple juice by sensory analysis and the population of A. acidoterrestris and incubation time at 21 and 37°C necessary for chemical detection of guaiacol. Commercially sterilized apple juice (pH 3.54 ± 0.04, 11.3 ± 0.3°Brix) was inoculated with a five-strain mixture of A. acidoterrestris spores (2.98 log10 CFU/ml) and stored at 21 or 37°C for up to 61 days. Using an experienced sensory panel and the forced-choice ascending concentration method of limits, the best estimate threshold (BET) for recognition of guaiacol added to uninoculated apple juice was 2.23 ppb. Numbers of A. acidoterrestris spores and cells in inoculated juice remained constant during the 61-day storage period; however, the panel detected (P ≤ 0.01) guaiacol in juice stored at 37°C within 8 days. At three of four sampling times ranging from 13 to 61 days at which the sensory panel detected (P ≤ 0.001) guaiacol, concentrations of 8.1 to 11.4 ppb were detected by chromatographic analysis. The panel detected (P ≤ 0.1 to P ≤ 0.01) guaiacol in five samples stored at 21 to 37°C for 8 to 61 days in which the compound was not detected by chromatographic analyses. It appears that guaiacol content in apple juice inoculated with A. acidoterrestris is not always correlated with numbers of cells, and the limit of sensitivity of chromatographic quantitation of the compound is higher than the BET.

scholarly journals FATTY ACID PROFILE OF NON-CONFORMING POOLED HUMAN MILK AS AFFECTED BY THE PROCESSING AND STORAGE CONDITIONS

2021 ◽  
Vol 9 (2) ◽  
pp. 46-54
Author(s):  
Otávio A. S. Ribeiro ◽  
Kely P. Correa ◽  
Mauricio O. Leite ◽  
Marcio A. Martins ◽  
Jane S. R. Coimbra
Keyword(s):  
Fatty Acid ◽  
Human Milk ◽  
Fatty Acid Profile ◽  
Storage Period ◽  
Storage Conditions ◽  
Milk Lipid ◽  
Fatty Acid Profiles ◽  
Operational Conditions ◽  
Processing And Storage ◽  
And Storage

The fatty acid's contents of non-conform pooled human milk can be affected by different processing and storage operational conditions. Besides, the knowledge of changes in the human milk fatty acid profile can help indicate its use in a given storage period, according to each newborn's specific need. Thus, in the present work, changes in the fatty acid profiles of three types of human milk (raw; pasteurized at 62.5 °C for 30 min; homogenized at 40 oC for 30 s followed by pasteurization) were studied during storage for six months in a freezer at -18 oC. Large variations were observed in the concentrations of polyunsaturated fatty acids, particularly of docosahexaenoic acid, with a reduction of almost 50% of its total. Palmitic and stearic acid contents also changed according to the conditions of processing and storage. Correlations between the decrease of long fatty acid chains and the increase of medium and short chains were verified.  Thus, we observe that operational conditions of processing and storing change human milk lipid profile, with some nutritional losses.

scholarly journals Volatile Changes during Storage of Shelf Stable Apple Juice: Integrating GC-MS Fingerprinting and Chemometrics

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 165 ◽  
Author(s):  
Biniam Kebede ◽  
Vivien Ting ◽  
Graham Eyres ◽  
Indrawati Oey
Keyword(s):  
Shelf Life ◽  
Solid Phase Microextraction ◽  
Apple Juice ◽  
Solid Phase ◽  
Storage Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Dimethyl Sulphide ◽  
Processing And Storage ◽  
Shelf Stable ◽  
And Storage

This is the first study to reveal potential markers for volatile changes during ambient and accelerated shelf life of pasteurized apple juice. The volatile changes were monitored at 20, 30 and 40 °C using a headspace solid-phase microextraction-gas chromatography-mass spectrometry fingerprinting method. Using modern chemometrics and feature selection, hexanal, trans-2-hexenal, dimethyl sulphide, furfural, ethyl acetate and 1-pentanol were chosen as potential shelf life markers. Volatiles associated with the green, grassy and fresh apple aroma, such as hexanal and trans-2-hexenal, decreased during storage, whereas thermal load and browning associated compounds, like dimethyl sulphide and furfural, increased during storage. Hexanal and trans-2-hexenal can be markers to monitor the change in green-apple like character. Furfural and dimethyl sulphide can be markers of temperature abuse during juice processing and storage. Furfural can also be an indicator for juice browning. The present work effectively identified potential markers to monitor and predict volatile aroma changes of shelf stable apple juice in different storage conditions. Sensory analysis can be conducted in the future to confirm the aroma relevance of selected markers.

scholarly journals Influence of Different Filling, Cooling, and Storage Conditions on the Growth of Alicyclobacillus acidoterrestris CRA7152 in Orange Juice

2009 ◽  
Vol 75 (23) ◽  
pp. 7409-7416 ◽  
Author(s):  
Ana Cláudia N. F. Spinelli ◽  
Anderson S. Sant'Ana ◽  
Salatir Rodrigues-Junior ◽  
Pilar R. Massaguer
Keyword(s):  
Orange Juice ◽  
Storage Temperature ◽  
Growth Parameters ◽  
Storage Conditions ◽  
Inoculum Level ◽  
Alicyclobacillus Acidoterrestris ◽  
Time Required ◽  
Cold Point ◽  
And Storage ◽  
A Current

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.

scholarly journals Determination of the Chemical Composition of Tea by Chromatographic Methods: A Review

2015 ◽  
Vol 4 (3) ◽  
pp. 56 ◽  
Author(s):  
Alexandr Ya Yashin ◽  
Boris V. Nemzer ◽  
Emilie Combet ◽  
Yakov I. Yashin
Keyword(s):  
Chemical Composition ◽  
Volatile Compounds ◽  
Black Tea ◽  
Storage Conditions ◽  
Organoleptic Evaluation ◽  
Chromatographic Methods ◽  
Tea Quality ◽  
Processing And Storage ◽  
And Storage

<p>Despite the fact that mankind has been drinking tea for more than 5000 years, its chemical composition has been studied only in recent decades. These studies are primarily carried out using chromatographic methods. This review summarizes the latest information regarding the chemical composition of different tea grades by different chromatographic methods, which has not previously been reviewed in the same scope. Over the last 40 years, the qualitative and quantitative analyses of high volatile compounds were determined by GC and GC/MS. The main components responsible for aroma of green and black tea were revealed, and the low volatile compounds basically were determined by HPLC and LC/MS methods. Most studies focusing on the determination of catechins and caffeine in various teas (green, oolong, black and pu-erh) involved HPLC analysis.</p> <p>Knowledge of tea chemical composition helps in assessing its quality on the one hand, and helps to monitor and manage its growing, processing, and storage conditions on the other. In particular, this knowledge has enabled to establish the relationships between the chemical composition of tea and its properties by identifying the tea constituents which determine its aroma and taste. Therefore, assessment of tea quality does not only rely on subjective organoleptic evaluation, but also on objective physical and chemical methods, with extra determination of tea components most beneficial to human health. With this knowledge, the nutritional value of tea may be increased, and tea quality improved by providing via optimization of the growing, processing, and storage conditions.</p>

scholarly journals Influence of drying methods on preservation of biologically active substances of garden strawberries being raw material for food enrichment

2021 ◽  
Vol 845 (1) ◽  
pp. 012094
Author(s):  
I M Novikova ◽  
O M Blinnikova ◽  
L G Eliseeva ◽  
D A Blinnikova
Keyword(s):  
Shelf Life ◽  
Storage Period ◽  
Storage Conditions ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Raw Material ◽  
Drying Methods ◽  
Urgent Problem ◽  
And Storage ◽  
Active Substances

Abstract At present, the preservation of the consumer properties of berry products is an urgent problem. Use of fresh garden strawberries is limited by a short storage period and seasonality. Under optimal storage conditions in a normal atmosphere, the average shelf life of strawberries is from 2 to 9 days depending on the variety. To meet the needs of the population in garden strawberries and meet the physiological needs in a unique complex of biologically active substances, strawberries are subjected to different processing methods. Drying being a type of fruit and berry products processing has the following advantages: a significant increase in the shelf life of products, a decrease in the mass and storage volumes of dried berries, preservation of minerals, carbohydrates, dietary fiber, antioxidants, bioflavonoids and many biologically active compounds in berries. Modern drying technologies allow preserving the content of essential vitamins to its full extent. Comparison of two technologies for drying garden strawberries has established that vitamins and other biologically active substances are well preserved in berries. Berries dried by convective vacuum-impulse method (CVI) are recommended to be used for food enrichment.

scholarly journals Growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions

2021 ◽  
Vol 51 (11) ◽  
Author(s):  
Joelson Sousa Lima ◽  
Ana Paula Presley Oliveira Sampaio ◽  
Mylla Christy da Silva Dufossé ◽  
Paula Fernanda Morais de Sousa ◽  
Josyane Brasil da Silva ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Growth Kinetics ◽  
Storage Conditions ◽  
Buffalo Milk ◽  
Production Chain ◽  
Pasteurized Milk ◽  
Processing And Storage ◽  
And Storage ◽  
Kinetics Of

ABSTRACT: Buffalo milk is rich in nutrients and can serve as a substrate for the proliferation of microorganisms. Thus, the objective of the present study was to evaluate the growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions. Samples of raw and pasteurized milk were inoculated with 1 CFU of each bacterium, separately and together, per 25 mL. After contamination, samples were stored at 8 °C or 37 °C, and bacterial counts were performed at 24, 48, and 168 h. In addition, the accompanying microbiota growth, pH, and the effect of these variables on the growth kinetics of microorganisms were monitored. The pathogens tested were able to proliferate under most conditions tested, reaching high titers throughout the experimental period. At 37 °C, there was a decrease in pH and an increase in the accompanying microbiota that interfered with the microbial growth curve. It was also observed that pasteurized milk subjected to 8 °C provided better conditions for the multiplication of bacteria. Therefore, it was concluded that care throughout the production chain, storage, and commercialization of milk must be adopted to guarantee the microbiological safety of this food.

scholarly journals An Investigation of Moroccan Vinegars: Their Physicochemical Properties and Antioxidant and Antibacterial Activities

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Driss Ousaaid ◽  
Hamada Imtara ◽  
Hassan Laaroussi ◽  
Badiaa Lyoussi ◽  
Ilham Elarabi
Keyword(s):  
Physicochemical Properties ◽  
Bioactive Compounds ◽  
Antibacterial Activities ◽  
Storage Conditions ◽  
Production Methods ◽  
Maximum Value ◽  
Processing And Storage ◽  
And Storage ◽  
Excellent Source

Vinegar is a natural product rich in bioactive compounds such as phenols, flavonoids, and organic acids. Several factors affect the quality of vinegars such as apple origin, environmental conditions, production methods, processing, and storage conditions. We investigated the quality of apple vinegars as well as their physicochemical properties and the antioxidant and antibacterial activities of vinegars collected from different areas in Morocco. For physicochemical properties, the outcomes showed the following values: pH (3.18–3.83), electrical conductivity (2.11–2.90), acidity (0.24–5.6), Brix (3.25–6), and density (1.0123–1.0233). The polyphenols content of samples was 68.91 mg AG/100 mL in sample S6 as the minimum value and 147.54 mg AG/100 mL in sample S2 as the maximum value. The best ability to scavenge the DPPH radical was observed in sample S3 (IC50 = 0.45 ± 0.013 µL/mL). Sample S2 showed moderate antibacterial effect against microorganisms tested with MICs ranging from 0.78 µL/mL to 1.125 µL/mL and with a diameter of inhibition ranging from 15.65 mm to 27.65 mm. In addition, a strong correlation was observed between the antibacterial activity of vinegars and physicochemical parameters (pH and total acidity). These outcomes have shown that our vinegar samples are an excellent source of bioactive compounds with potent antioxidant and antibacterial potentials.

Survey of Cyclohexylamine Content of Food Products Containing Cyclamates

1970 ◽  
Vol 53 (6) ◽  
pp. 1120-1128
Author(s):  
T Fazio ◽  
J W Howard ◽  
E O Haenni
Keyword(s):  
Weight Control ◽  
Food Product ◽  
Storage Conditions ◽  
Major Type ◽  
Processing And Storage ◽  
Relationship Of ◽  
The Relationship ◽  
And Storage ◽  
Hydrolysis Of ◽  
Content Range

Abstract A national survey was conducted to ascertain the relationship of the cyclohexylamine content of cyclamate-containing products to their composition, processing, and storage conditions. Cyclohexylamine was found in 174 of the 232 samples examined. The cyclohexylamine content range for each major type of food product was as follows: 0.0–8.2 ppm for carbonated beverages; 0.0–5.8 ppm for dry beverage bases; 0.0–1.5 ppm for fruit juices; 0.0–0.8 ppm for weight control foods; and 0.3–66 ppm for food sweetener preparations (liquid and dry base). No correlation between the cyclamate content of products and the cyclohexylamine present was evident. However, the findings indicate that significant hydrolysis of cyclamate can occur.

Sign in / Sign up

Export Citation Format

Share Document