Early Spoilage Research Articles

Validation of Novel Cultured Cane Sugar and Vinegar Powder to Extend Shelf Life in Fresh Turkey Sausage

ObjectivesThe objective of this study was to assess the antimicrobial efficacy of Verdad® Opti. Powder N70 (CSV-P) on inhibition of aerobic plate counts, lactic acid bacteria, and Enterobacteriacae growth kinetics in fresh turkey sausage formulation for 24 d of storage at 40°F. Materials and MethodsFresh turkey sausage formulation containing turkey thigh and skin, water, sea salt, and different levels of natural antimicrobial interventions: (A) Control, (B) 1.55% CSV-P, (C) 2.1% CSV-P, and (D) 2.5% CSV-P. Each treatment was prepared independently, ground, mixed, vacuum stuffed, clipped, and incubated at 40°F. Table 1 outlines the treatment structure, proximate values for the treatments and the different microorganisms outgrowth data. The samples were enumerated for aerobic plate counts (APC), lactic acid bacteria (LAB), Enterobacteriacae (in duplicate), at 6 regular intervals for 24 d of incubation, using Tryptic Soy Agar plate, MRS and VRBG Agar, respectively. Proximate analyses were performed for all the treatments. ResultsTreatments containing CSV-P in general, had lower aw values in comparison to control (Table 1). Water activity is a major factor influencing the outgrowth of lactic acid bacteria strains, thereby preventing early spoilage. The antimicrobial treatments had no major impact on the ionic strength of the formulations as evidenced by similar pH values. The use of CSV-P at 1.55%, 2.10% and 2.50%, showed control of APC outgrowth. CSV-P treatments at all use level also delayed the outgrowth of LAB and Enterobacteriaceae counts compared to the control treatment. The 8 log10 CFU/g limit for APC and LAB bacteria outgrowth was reached in 7 and 6 d, for control treatment, respectively. The 8 log10 CFU/g limit for APC and LAB outgrowth was reached for 1.55% CSV-P in 9 and 7 d, 2.10% CSV-P in 12 and 12 d, and 2.50% CSV-P in 14 and 13 d, respectively. Enterobacteriacae counts did not exceed 1 log10CFU/g increase during 21 d of incubation for any treatments containing CSV-P. ConclusionThe research validates the antimicrobial efficacy of cultured cane sugar and vinegar powder to control the outgrowth of APC, LAB and Enterobacteriacae, thus providing the industry with an effective natural and clean label antimicrobial solution to improve shelf life and food safety in fresh poultry sausage.

Microbiological, chemical and sensory spoilage analysis of raw Atlantic cod (Gadus morhua) stored under modified atmospheres

During fish spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (%v/v CO2/O2/N2) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 °C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7–7.5 log). Monitoring of early spoilage thus calls for sensitivity for low VOC concentrations.

14. Effect of Curry Leaf (Murraya koenigii) Extract to Early Spoilage of Beef

This study aimed to determine early spoilage of beef after addition of curry leaf extract. The sample used is beef Semimembranosus muscle which is divided into 42 parts each weight is 5 grams. This research used experimental method which consists of three treatments with two repetitions. P1 group is without curry leaf extract (control), group P2 with curry leaf extract 25% used and group P3 with curry leaf extract 50%. The entire sample is stored in a refrigerator at 4 ° C. For 7 days early spoilage test is conducted every day at 9am and 4pm. The result showed difference early spoilage time between each treatment. In P1 positive result of early spoilage time is on the 4th day and P2 positive result of early spoilage time is on the 5th day. While in P3 has not obtained positive result of early spoilage time at 7 days storage. Based on the results of this study we concluded that curry leaf extract can slow down the early spoilage time of beef

GaN Based Ethanol Sensor

Ethanol is one of most common aliphatic alcohol, which is used in chemical, biomedical, and food industry including alcoholic beverage. In recent, there are growing demands for the ethanol gas sensor to detect early spoilage of carbohydrate food, and this kind of sensors are to be employed in consumer electronics including refrigerators and mobile devices. Electrochemical, optical, potentiometric, polymer, and semiconductor sensors have been developed for fast and accurate detection of ethanol. Among the various detection methods, semiconductor based sensor can be operated at low power consumption in compact size. So far now, metal oxide semiconductors such as SnO2, Fe2O3, CuO, and ZnO are researched mostly.GaN based material is very suitable for gas sensors, and has many superior material properties to oxide semiconductors. Wide bandgap of GaN enable devices to be operated at high temperature and harsh radiative environment, and mechanical and chemical robustness of GaN ensures reliability and durability of the device. Many types of GaN based gas sensing devices including Schottky diodes, metal oxide semiconductor (MOS) diodes, GaN nanowires and AlGaN/GaN high electron mobility transistors (HEMTs) which employ specific sensing material as a catalytic active layer have been developed for prompt and sensitive detection of target gas. Specially, AlGaN/GaN HEMT structure with 2 dimensional electron gas (2-DEG) channel induced by piezoelectric and spontaneous polarization at the interface between the AlGaN and GaN layers shows highly sensitive current changes to surface charges created by catalytic reaction of target gas on the specific active sensing layer. Typically, field effect transistors with higher drain current exhibit better responsivity of gas detection. With 30 % Al concentration in AlGaN layer, 5~10 times higher channel sheet electron densities are obtained compared to GaAs or InP HEMTs.In this study, AlGaN/GaN HEMT based Schottky diode ethanol sensor using silver as a sensing material was fabricated, and the response of the device to ethanol gas was investigated. The diode showed current reduction in ethanol ambient due to the increase of Shottky barrier height at 250oC, and fast reliable repeatability to cyclic exposures of various concentrations of ethanol gas.

Modeling the Time to Fail of Peach Nectars Formulated by Hurdle Technology

The use of regression with life-data is helpful to observe whether one or more factors affect the failure time (spoilage) of a product, obtaining a model that predicts the time to fail (TTF). TTF models link kinetic (lag time) and probabilistic (growth /no-growth prediction) models for selected formulation/storage conditions. Our objective was to assess the individual and combined effects of pH, aw, and the incorporation of potassium sorbate (KS) or sodium benzoate (BNa) at selected concentrations on the microbial stability of peach nectar during storage at 25°C, in order to model and predict TTF. Peach nectars were formulated with 40% fruit pulp and the necessary sucrose syrup and citric acid to attain aw 0.96, 0.97, or 0.98 and pH 3.0, 3.5, or 4.0; while 0, 500, or 1000ppm of KS or BNa were added. Nectars were stored for 180 days in glass jars at 25°C, and periodically analyzed (standard plate as well as yeast and mould counts). The experimental design and analyses were replicated three times. Storage times that revealed microbial populations higher than 104 CFU/mL and signs of spoilage were registered to model TTF by survival analysis. From the 54 combinations tested, 9 formulations (without antimicrobials) exhibited early spoilage (<5 days). For the combinations formulated with 500ppm of BNa, spoilage was detected after 30 days; much longer spoilage times were observed for nectars with 1000ppm of KS or BNa. In general, KS was more effective than BNa in delaying spoilage when 1000ppm were added. TTF models included individual and interaction effects of the evaluated factors and revealed good agreement among experimental and predicted data (R2>0.90). Survival analysis through TTF models can be used to predict spoilage time under specific factor combinations or to select factor levels for a specific shelf-life of peach nectars.

Microbiological Evaluation of Ultra-High-Temperature (UHT)-Treated Milk Close to Expiry Date and Routine Home Practices for Preservation of Milk.

Background:As milk is an excellent medium for growth of microorganisms, milk gets contaminated very easily leading to its early spoilage and to milk-borne diseases.Objectives:To compare the quality of pasteurized milk with milk cooker-treated milk and to compare the quality of fresh ultra-high-temperature (UHT) milk with that of UHT milk close to expiry date.Materials and Methods:Samples of pasteurized milk, milk heated in milk cooker, fresh UHT milk, and UHT milk nearing expiry date were tested by methylene blue reduction test, coliform test, and colony count test. The results were analyzed statistically using Statistical Package for Social Sciences (SPSS) version 11.5.Results:All milk samples passed the methylene blue test and UHT-treated milk passed the coliform test also. Out of the 30 fresh pasteurized milk samples, seven (23.3%) passed the coliform test; but the same after milk cooker treatment, 16 (53.3%) passed the coliform test (P < 0.05). Fourteen (46.6%) out of 30 fresh pasteurized milk samples failed the colony count test, but the same after milk cooker treatment only eight (26.6%) failed the test (P = 0.583). Only seven out of the 60 UHT milk samples failed the colony count test and out of these six (20%) were close to expiry date (P < 0.05).Conclusions:Milk cooker-treated milk appears to be safer than the fresh pasteurized milk. Fresh UHT-treated milk is safer then UHT milk close to expiry date.

Psychrotrophic lactic acid bacteria associated with production batch recalls and sporadic cases of early spoilage in Belgium between 2010 and 2014

Between 2010 and 2014 several spoilage cases in Belgium occurring in retail foodstuffs prior to the end of shelf-life have been reported to our laboratory. Overall, seven cases involved strictly psychrotrophic lactic acid bacteria (LAB) contamination in packaged and chilled-stored food products. The products derived either from recalls of entire production batches or as specimens of sporadic spoilage manifestations. Some of these samples were returned to the manufacturing companies by consumers who observed the alterations after purchasing the products.The products covered a wide range of foodstuffs (i.e. meat, dairy, vegetable, egg products and composite food) and denoted different spoilage defects. However, the microbiota determined by means of 16S rRNA gene high-throughput sequencing analysis underpin few LAB genera (i.e. Leuconostoc, Lactobacillus, Weissella and Lactococcus), which are frequently encountered nowadays as specific spoilage organisms (SSO) albeit overlooked by mesophilic enumeration methods due to their strictly psychrotrophic character. The present study confirms the spreading of psychrotrophic LAB in Belgian food processing environments leading to unexpected spoilage, corroborating their spoilage dynamics and prevalence in all kinds of packaged and refrigerated foodstuffs in Northern Europe.

Study on bacteriological quality of Kunun aya (Tigernut juice) sold at Umaru Musa Yar’adua University (UMYU) campus, Katsina

The study was aimed at determining the Bacteriological quality of Kunun aya (Tigernut juice) which is one of the most regularly non-alcoholic drinks consumed within Umaru Musa Yar’adua University campus. Samples were collected and analyzed from different places at the University for the Enumeration of bacteria. Serial dilutions were carried out from the collected samples where a dilution factor of 10-5 was obtained for each sample. Total aerobic bacterial counts, total coliform counts and Salmonella-Shigella counts were determined from the samples using Pour Plate Technique. The results obtained shows high bacterial load as the total aerobic bacterial counts had a range of 2.2x104 - 1.4x106 cfu/ml. Total coliform counts had 8.2 x 102 - 6.1 x 104 cfu/ml while Salmonella-Shigella counts had 1.1 x 102 - 8.7 x 104 cfu/ml. The result shows high bacterial contamination of Kunun aya, which may be obtained from the poor hygienic preparation process. This could be the reason for its quick spoilage. Preserving the drink in very low temperature may reduce the chances for its early spoilage. DOI: http://dx.doi.org/10.3126/ije.v3i2.10518 International Journal of the Environment Vol.3(2) 2014: 87-97

Photopyroelectric Detection of Vegetable Oils' Adulteration

Highly accurate photopyroelectric (PPE) investigation, in the thermal-wave-resonator-cavity configuration, was combined with gas chromatography (GC), in order to detect adulteration of flax oil by mixing with sunflower oil. It was found that the value of the thermal diffusivity for the investigated mixtures ranges from 8.07 × 108m2/s (pure sunflower oil) to 10.03 × 108m2/s (pure flax oil) and is directly correlated with the total amount of the polyunsaturated fatty acids from oils composition. The correlation between the PPE signal and the composition of unadulterated and adulterated vegetable oils confirms the data obtained previously on fresh and spoiled vegetable oils and suggests that the thermal diffusivity may be a suitable parameter to detect oils' quality and their early spoilage and adulteration.

자반고등어에서 histamine 분해능을 가진 세균의 분리 동정

Histamine can be produced at early spoilage stage through decarboxylation of histidine in red-flesh fish by Proteus morganii, Hafnia alvei or Klebsiella pneumoniae. Allergic food poisoning is resulted from the histamine produced when the freshness of Mackerel degrades. Conversely it has been reported that there are bacteria which decompose histamine at the later stage. We isolated histamine decomposers from salted mackerel and studied the characteristics to help establish hygienic measure to prevent outbreak of salted mackerel food poisoning. All the samples were purchased through local supermarket. Histamine decomposers were isolated using restriction medium using histamine 10 species were selected. Identification of these isolates were carried out by the comparison of 16S rDNA partial sequence; as a result, we identified Pseudomonas putida strain RA2 and Halomonas marina, Uncultured Arctic sea ice bacterium clone ARKXV1/2-136, Halomonas venusta, Psychrobacter sp. HS5323, Pseudomonas putida KT2440, Rhodococcus erythropolis, Klebsiella terrigena (Raoultella terrigena), Alteromonadaceae bacterium T1, Shewanella massilia with homology of respectively. Turbidometry determination method and enzymic method were employed to determine the ability of histamine decomposition. Among those species Shewanella massilia showed the highest in ability of histamine decomposition. From these results we confirmed various histamine decomposer were present in salted mackerel product in the market.

Sensory, microbiological, and chemical spoilage of cultured common sea bass ( Dicentrarchus labrax) stored in ice: a seasonal differentiation

Common sea bass ( Dicentrarchus labrax) of a Greek cage-culture origin, sampled in December and July, were stored in ice, and their sensory, microbiological and chemical spoilage patterns were studied as well as their seasonal differentiation. The sensory storage life was determined at 15 days of ice storage. The microbial population in the muscle reached levels of 105 at the acceptability limit. The ATP breakdown pattern showed a quick depletion of inosine-monophosphate (IMP) in the first 8–9 days of ice storage and slower depletion thereafter. Inosine (INO) and hypoxanthine (Hx) were formed at significant quantities. TVBN and TBA, as indicators of protein breakdown and lipid oxidation, respectively, showed low and delayed increase. A seasonal effect was observed with summer fish showing higher rates of K-value increase during early spoilage, while winter fish showed higher K-values, microbial populations and TVBN at late spoilage stages.

Association of psychrotrophic Clostridium spp. with deep tissue spoilage of chilled vacuum-packed lamb

Early spoilage of commercial vacuum-packed chilled lamb legs was manifested as an objectionable ‘cheesy’, deep tissue odour that became evident when a cut was made into the stifle joint. Investigation of the probable causative agents led to the isolation of two psychrotrophic strains of clostridia. The isolates could not be identified using traditional identification schemes. One isolate was able to produce strong, objectionable ‘cheesy’ odours in deep tissues of artificially inoculated beef.

Ecology of controlled soyabean acidification for tempe manufacture

During the traditional Indonesian tempe manufacturing process, spontaneous and uncontrolled fermentations of soyabeans take place during the soaking stage prior to fungal fermentation. Often, such fermentations result in an acidification of the beans. A comparison of industrial tempe processes suggested that fermentative acidification during soaking inhibits the multiplication of spoilage causing bacilli. The acidification during soaking could be controlled by recycling part of the soak water from a previous batch as an inoculum, resulting in a soak water pH of 4·1–4·9 depending on soaking temperature and recycling rate. Soaks at 19°C and 25°C were dominated by Lactobacillus plantarum. Isolates of L. plantarum added as an inoculum to freshly started soaks were able to acidify the beans to pH ≤ 4·30 yielding tempe of good quality in which bacilli and Enterobacteriaceae could not be detected. Yeasts, notably Saccharomyces dairensis, present in soaks at 19°C and 25°C, did not contribute to the acidification and could not prevent early spoilage of tempe. Pediococcus spp. dominated soaks at 37°C, and though able to acidify soyabeans, inhibited the growth of Rhizopus oligosporus; hence no tempe could be formed. Our findings indicate that a simple recycling process can result in predictable acidification during soaking of soyabeans, contributing to the shelf-life and safety of tempe.

Grading Fish for Quality. 3. Grading of Recently Cut Fillets

Panels of experienced fish-plant foremen and government fresh-fish inspectors graded cod and haddock in the round or as gutted whole fish, and subsequently graded the same fish as fillets. The results show that in general the two sets of gradings were very similar, and that both showed a close correlation with the trimethylamine (TMA) value of the fish muscle. When the fish was relatively fresh (TMA value 0.1 to 1.5), there was a slight tendency for the panels to be more severe in grading the fillets than the corresponding whole fish. As spoilage progressed, this trend reversed.The results suggest that during the earlier stages of spoilage it is easier for a grader to judge the quality of a fish by examining the changes occurring on the exterior of the whole or gutted fish than by examining the fillet cut from it. This is particularly so where the grader cannot give careful attention to the early spoilage odours developing in the fillet.There are definite exceptions to the usual close correlation between the quality of cod or haddock fillets and their TMA values. Bilgy fish, ungutted fish, and certain types of very soft-textured fish may be of very poor quality and still have a relatively low TMA value. These exceptions are discussed in their relation to a system of grading for cod and haddock based on organoleptic examination and supported by TMA values as objective standards of quality.

魚の死後電気抵抗変化における一考察(予報)

The electric resistance of the muscles of carp, Cyprinus carpio, and crucian carp, Cyprinus carassius, was measured by a KOHLRAUsH bridge type instrument in the course of deterioration at 17°, 20°, 25° and 30°C. The organoleptic observations and the determination of ATP and free SH group were also carried out. It was observed, as shown in Fig. 2, that the curve of electric resistance lowered stepwise and the curve was distinguishable into six parts in total, in which the steep and the flat parts alternated. From the organoleptic observations and the determination of ATP and free SH group, the author assumed that these six parts indicate successively before rigor, full rigor, after rigor, autolysis, early spoilage, and advanced spoilage stages.

Spoilage of Haddock in the Trawlers at Sea: The Measurement of Spoilage and Standards of Quality

During a period of eight months, 850 haddock were taken from a trawler from the Nova Scotian and Grand Banks. Immediately after landing, the fish were filleted and the fillets were examined organoleptically and tested for pH and trimethylamine.The results indicate a rather close correlation between the development of early spoilage odours and the increase of trimethylamine. One marked exception was the development of "bilgy" odours which can become very offensive without an increase in the trimethylamine content of the muscle.Sixty-five per cent of the fillets without perceptible spoilage odours had trimethylamine values of less than 1 mg. per 100 g.; 83 per cent had values of less than 1.5 mg., 92.5 per cent of less than 2 mg.; only 0.5 per cent had trimethylamine values of between 3 and 4 mg. and none above that level. Conversely, only 10.5 per cent of the "smelly" fish had trimethylamine values below 1 mg.; 89.5 per cent had values above 1.0 mg., and 66.5 per cent above the 1.5-mg. level. For the purpose of grading freshly cut haddock fillets, the following standards are suggested: trimethylamine values of 0 to 1 mg. per 100 g.–fresh; 1 to 5 mg.–doubtful or spoiling; above 5 mg.–spoiled.In spite of its usefulness as a measure of spoilage, it seems very unlikely that trimethylamine contributes to the early spoilage odours that develop in haddock muscle before the pH reaches 6.9.The pH of the homogenized muscle is not a good indication of the extent of deterioration that takes place in the earlier stages of spoilage of these fish.

PH 價による魚介類の鮮度測定

Present paper concerns with the accuracy and usefulness of pH determination in terms of freshness of fishes. A special glass electrode (Fig. 1) connected with an amplifier capable of reading exactly 0.50mV intervals was used. The results obtained are shown in Fig. 2-5 and Tab. 1-4, and may be summarized as follows: (1) The pH value of fish meats will be adopted as a criterion of the freshness of fishes to some extent. (2) However, the pH value varies according to the part of a body. And some divergencies are also observed according to the fishing season and species of fishes. (3) The pH value of fish meats at the early spoilage was 6.85 in the fishes of white meat and 6.27 in those of red meat.

Studies of Fish Spoilage: VI. The Breakdown of Carbohydrates, Proteins and Amino Acids During Spoilage of Cod Muscle Press Juice

Autolytic changes in cod muscle press juice are negligible in proportion to the changes resulting from bacteria ordinarily contaminating the press juice during its preparation. During early spoilage, the greater part of the bacterial action on expressate even in intimate contact with air is the result of anaerobic growth. Later, when the press juice is definitely spoiled, aerobic oxidation assumes the major part if air is available. Spoilage in sea fish expressate always occurs in two stages irrespective of the availability of air, first the oxidation of lactic acid and sugar, and second that of amino acids and the hydrolysis of proteins. The second stage represents advanced spoilage. As trimethylamine production occurs mainly during the first stage, it is a good criterion as to the probable production of toxic compounds resulting from protein and amino acid breakdown.