Odor Defects Research Articles

Low-cost, on-farm intervention to reduce spores in bulk tank raw milk benefits producers, processors, and consumers

Bacterial spores, which are found in raw milk, can survive harsh processing conditions encountered in dairy manufacturing, including pasteurization and drying. Low-spore raw milk is desirable for dairy industry stakeholders, especially those who want to extend the shelf life of their product, expand their distribution channels, or reduce product spoilage. A recent previous study showed that an on-farm intervention that included washing towels with chlorine bleach and drying them completely, as well as training milking parlor employees to focus on teat end cleaning, significantly reduced spore levels in bulk tank raw milk. As a follow up to that previous study, here we calculate the costs associated with that previously described intervention as ranging from $9.49 to $13.35 per cow per year, depending on farm size. A Monte Carlo model was used to predict the shelf life of high temperature, short time fluid milk processed from raw milk before and after this low-cost intervention was applied, based on experimental data collected in a previous study. The model predicted that 18.24% of half-gallon containers of fluid milk processed from raw milk receiving no spore intervention would exceed the pasteurized milk ordinance limit of 20,000 cfu/mL by 17 d after pasteurization, while only 16.99% of containers processed from raw milk receiving the spore intervention would reach this level 17 d after pasteurization (a reduction of 1.25 percentage points and a 6.85% reduction). Finally, a survey of consumer milk use was conducted to determine how many consumers regularly consume fluid milk near or past the date printed on the package (i.e., code date), which revealed that over 50% of fluid milk consumers surveyed continue to consume fluid milk after this date, indicating that a considerable proportion of consumers are exposed to fluid milk that is likely to have high levels spore-forming bacterial growth and possibly associated quality defects (e.g., flavor or odor defects). This further highlights the importance of reducing spore levels in raw milk to extend pasteurized fluid milk shelf life and thereby reducing the risk of adverse consumer experiences. Processors who are interested in extending fluid milk shelf life by controlling the levels of spores in the raw milk supply should consider incentivizing low-spore raw milk through premium payments to producers.

Investigating the Quality and Efficiency of Biosolid Produced in Qatar as a Fertilizer in Tomato Production

This study evaluated biosolid quality over time and the efficiency of using amounts (5 and 7 kg/m2) of municipal class A biosolids in Qatar to fertilize tomato plants (Solanum lycopersicum). Random samples were subjected to physical and chemical analysis, which revealed excellent particle uniformity and stability with minor odor defects. The analysis confirmed the product was nutrient-rich while pollutant levels were below the international standards. The nominated rates were used to fertilize tomato plants in pots grown in a greenhouse for four months with a control treatment of manure and Peat-Moss, before measuring the plant biological characteristics. Plants were examined via chemical analysis of nutrients and pollutants both for the whole plant and for stems, fruits, and leaves. Results indicated that both experimental treatments enhanced plant growth and development as compared to the control treatment. However, the chemical analyses also revealed levels of zinc, copper, and manganese in the plant fruits that were well in excess of the maximum acceptable levels, as defined by international health organizations. This study found that while the application of class A biosolids as organic fertilizer for tomato plants greatly enhanced the overall plant growth, the plant fruits contained toxic levels of trace heavy metals.

From Extra Virgin Olive Oil to Refined Products: Intensity and Balance Shifts of the Volatile Compounds versus Odor.

To explore relationships between the volatile organic compounds (VOCs) of different grades of olive oils (OOs) (extra virgin olive oil (EVOO), refined olive oil (ROO), and pomace olive oil (POO)) and odor quality, VOCs were measured in the headspace of the oils by proton transfer reaction quadrupole ion guide time-of-flight mass spectrometry. The concentrations of most VOCs differed significantly between the grades (EVOO > ROO > POO), whereas the abundance of m/z 47.012 (formic acid), m/z 49.016 (fragments), m/z 49.027 (fragments), and m/z 115.111 (heptanal/heptanone) increased in that order. Although the refined oils had considerably lower VOC abundance, the extent of the decline varied with the VOCs. This results in differences in VOCs proportions. The high VOC abundance in the EVOO headspace in comparison to ROO and POO results in a richer and more complex odor. The identified C5–C6 compounds are expected to contribute mainly to the green odor notes, while the identified C1–C4 and C7–C15 are mainly responsible for odor defects of OOs. Current results reveal that processing strongly affects both the quantitative and relative abundance of the VOCs and, therefore, the odor quality of the various grades of OOs.

Detection of Odor Defects in Boiled Cod and Trout by Gas Chromatography-Olfactometry of Headspace Samples

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetection of Odor Defects in Boiled Cod and Trout by Gas Chromatography-Olfactometry of Headspace SamplesChristian Milo and Werner GroschCite this: J. Agric. Food Chem. 1995, 43, 2, 459–462Publication Date (Print):February 1, 1995Publication History Published online1 May 2002Published inissue 1 February 1995https://doi.org/10.1021/jf00050a038RIGHTS & PERMISSIONSArticle Views362Altmetric-Citations83LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (433 KB) Get e-Alerts Get e-Alerts

Canadian Fish Products — Fish Inspection and Sensory Evaluation

Sensory analysis is a major tool in fish inspection for the evaluation of a wide range of products in many different locations. All fish and fish products produced in Canada for domestic interprovincial and export sales (and all imported products) must be inspected for quality and safety in accordance with the Fish Inspection Act and Regulations. Inspection includes label and product integrity examinations, and chemical, microbiological and sensory testing. Special applications of sensory evaluation in the Inspection Services Directorate of the Department of Fisheries and Oceans include training courses in sensory analysis, the ongoing development of product grade standards and the definition of product defects including reference chemical for flavors and odor defects, the development of sensory procedural manuals and of standards for testing facilities, and the promotion of uniform application of these standards and procedures nationally.

Flavor and Odor Defects of Gamma-Irradiated Skimmilk. II. Identification of Volatile Components by Gas Chromatography and Mass Spectrometry

Flavor and Odor Defects of Gamma-Irradiated Skimmilk. II. Identification of Volatile Components by Gas Chromatography and Mass Spectrometry

Flavor and Odor Defects of Gamma-Irradiated Skimmilk. I. Preliminary Observations and the Role of Volatile Carbonyl Compounds1,2

Summary To gain insight into the radiation-induced flavor and odor problem of skimmilk, the effects of ionizing (gamma) radiations at two dosages, 2×10 6 and 5×10 6 rep, on skimmilk and certain of its fractions were studied. Among the effects noted were fragmentation and aggregation of the proteins, activation of sulfhydryl groups, lowering of pH, and an increase in titratable acidity, browning, and the production of off-flavor and odor compounds. All of these changes were intensified at the 5×10 6 rep level of radiation. Of the volatile carbonyl compounds produced in skimmilk by radiation, acetaldehyde seems to be the only one of flavor significance (malty). The principal radiation-induced off-flavor appears to arise from a group of potent, disagreeable-smelling sulfur compounds. Methyl mercaptan, methyl sulfide, and methyl disulfide are postulated as dominant members of this group. These compounds originate primarily from the milk protein (casein). Radiation of aqueous lactose solutions produced acids which, outside of sourness, had no flavor or odor.

Cryophilic Organisms in Water and Butter

Summary 1.In plating out creamery water samples and butter samples on two differential media, it was found that 20° C. incubation gave, in most cases, the highest counts. However, 8° C. incubation yielded counts that were of considerable magnitude. In no sample did 37° C. incubation produce maximum total counts. 2.Caseolytic and lipolytic cultures capable of vigorous growth at 8° C. were isolated and purified. Of the forty-one cultures studied, twenty-eight belonged to the genus Pseudomonas, five to the genus Flavobacterium, six were species of Alcaligenes, one was classified as an Achromobacter, and one was a non-lactose-fermenting yeast. 3.Incubation studies using sterile cream inoculated with pure cultures showed that a large majority of these cultures were capable of causing extensive deterioration as measured by odor production. The production of odor defects typical of each culture depended on the temperature and the time of incubation. 4.The effect of five pure cultures on cream and skim milk was observed organoleptically and measured by acidity and formol titration. It was found that the intensity of the odor production was not correlated with extensive protein deterioration, as measured by the formol titration. It was also observed that odor production was more intense in cream than in skim milk. Positive qualitative tests for hydrogen sulfide and the presence of mercaptans were obtained during the process of distillation of several of the cultured cream samples.