ABSTRACT
Sliced saveloy samples were inoculated with monocultures of four potential spoilage bacteria and studied during a four week storage period. The objective was to investigate the resulting changes in the composition of Volatile Organic Compounds (VOCs) and the sensory quality of the product. Based on the sensory scores and the VOC composition Brochothrix thermosphacta, Chryseomonas luteola and Carnobacterium maltaromaticum were found to have a high spoilage potential in saveloy samples subjected to consumer simulated storage during the fourth week. Inoculation with Leuconostoc carnosum only resulted in a low level of spoilage. The sensory changes in the saveloy samples were modeled based on the VOC composition using Partial Least Squares Regression. The changes in the six sensory descriptors were closely related to the amount of diacetyl, acetoin, 2- and 3-methylbutanol, 2- and 3-methylbutanal and 2-methylpropanol found in the samples. These compounds are therefore potentially important for the shelf-life of sliced saveloy.
Subject(s)
Bacteria , Food Microbiology , Meat Products/microbiology , Odorants , Volatile Organic Compounds/metabolism , Animals , Food Storage , Humans , Least-Squares AnalysisABSTRACT
The aroma composition, the microbial composition and the sensory profile were measured in sliced saveloy samples packed in modified atmosphere (MA). The main objective was to identify aroma compounds with potential as chemical markers to identify the sensory changes of saveloy. The 60 aroma compounds isolated from the saveloy samples by dynamic headspace extraction and measured by Gas Chromatography Mass Spectrometry (GC-MS) were used to model the sensory attributes sour&old odour and meaty odour using partial least squares regression (PLS). 2- and 3-methylbutanal, 2- and 3-methylbutanol, acetoin and diacetyl were found to have the highest impact on both sour&old odour and meaty odour of the samples. The results show that these four aroma compounds have high potential as chemical markers for the sensory shelf-life of sliced and MA-packed saveloy.
Subject(s)
Food Contamination/analysis , Food Preservation/methods , Meat Products/analysis , Odorants/analysis , Acetoin/analysis , Aldehydes/analysis , Aldehydes/metabolism , Animals , Diacetyl/analysis , Food Microbiology , Food Packaging/methods , Gas Chromatography-Mass Spectrometry , Least-Squares Analysis , Pentanols/analysis , Pentanols/metabolism , Smell , Swine , Taste , Volatile Organic Compounds/analysisABSTRACT
BACKGROUND: Endoscopic screening and surveillance of cirrhotic patients for oesophageal varices is advocated before initiation of prophylactic therapy for prevention of the first variceal haemorrhage. AIMS: To compare the diagnostic yield of oesophageal capsule endoscopy (ECE) with Esophagogastroduodenoscopy (EGD) for detecting and grading oesophageal varices and to determine patient tolerance for each procedure. PATIENTS: Twenty consecutive cirrhotic patients scheduled for EGD were enrolled in the study. METHODS: Patients underwent ECE followed by EGD. Patients completed a visual analogue scale after each procedure, assessing level of anxiety, pain, overall satisfaction, and willingness to repeat each procedure. RESULTS: On EGD, 19/20 patients had oesophageal varices. ECE detected varices in 13/19 (68% sensitivity). ECE identified nine out of ten varices rated grade II or higher on EGD. The post-study analogue scale showed a greater level of anxiety before EGD (avg. 2.75/10) versus ECE (avg. 1.5/10). CONCLUSIONS: ECE may be used in the assessment of EV. It appears to have more discordance with EGD when evaluating smaller varices. The minimal discomfort, lack of sedation, and decreased risk make ECE a possible substitute to EGD in patients unable or unwilling to undergo EGD.
Subject(s)
Capsule Endoscopy/methods , Esophageal and Gastric Varices/diagnosis , Adult , Diagnosis, Differential , Endoscopy, Gastrointestinal/methods , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pain Measurement , Pilot Projects , Prospective Studies , Reproducibility of Results , Severity of Illness Index , Surveys and QuestionnairesABSTRACT
AIMS: To optimize the practical use of the bacteriocin producing Leuconostoc carnosum 4010 in order to inhibit the growth of Listeria monocytogenes in sliced meat products. METHODS AND RESULTS: Four different methods for biopreservation using the partially purified bacteriocin or the living culture of Leuc. carnosum 4010 were evaluated. The methods using the living protective culture added to the sliced gas packed meat product were more effective in preventing growth of L. monocytogenes than the use of the partially purified leucocins 4010 or bacteriocin produced during fermentation before heat treatment of the saveloy. The application method giving the highest reduction in L. monocytogenes used nozzles for sprinkling the protective culture on all surfaces of each slice of the meat product. In the control samples without the protective culture, L. monocytogenes grew to ca. 107 CFU g(-1), whereas for the application method using nozzles for distributing the protective culture, counts of L. monocytogenes never exceeded 10 CFU g(-1) during 4 weeks of storage at 10 degrees C. CONCLUSIONS: The live cells of the bacteriocin producing Leuc. carnosum 4010 was the most efficient method as it inhibited the growth of L. monocytogenes in cooked, sliced and gas packed saveloy stored at 5 and 10 degrees C for 4 weeks. SIGNIFICANCE AND IMPACT OF THE STUDY: The results indicate that biopreservation with lactic acid bacteria is a suitable alternative to chemical preservatives. An even distribution of the protective culture was found to be essential for the efficacy of the protective culture in pilot plant trials.
