Development of the Consumer Refrigerator Safety Questionnaire (CRSQ): A Measure of Consumer Perceptions and Practices

Food preparation and storage behaviors in the home deviating from the ‘best practice’ food safety recommendations may result in food borne illnesses. Currently, there are limited tools available to fully evaluate the consumer knowledge, perceptions and behavior in the area of refrigerator safety. The current study aimed to develop a valid and reliable tool in the form of a questionnaire (CFSQCRSQ) for assessing systematically all these aspects. Items relating to refrigerator safety knowledge (n=17), perceptions (n=46), reported behavior (n=30) were developed and pilot tested by an expert reference group and various consumer groups to assess face and content validity (n=20), item difficulty and item consistency (n=55) and construct validity (n=23). The findings showed that the CFSQCRSQ has acceptable face and content validity with acceptable levels of item difficulty. Item consistency was observed for 12 out of 15 refrigerator safety knowledge. Further, all five of the subscales of consumer perceptions of refrigerator safety practices relating to risk of developing foodborne disease food poisoning showed acceptable internal consistency (Cronbach’s α value > 0.8). Construct validity of the CFSQCRSQ was shown to be very good (p=0.022). The CFSQCRSQ exhibited acceptable test-retest reliability at 14 days with majority of knowledge items (93.3%) and reported behavior items (96.4%) having correlation coefficients of greater than 0.70. Overall, the CFSQCRSQ was deemed valid and reliable in assessing refrigerator safety knowledge and behavior and therefore has the potential for future use in identifying groups of individuals at increased risk of deviating from recommended refrigerator safety practices as well as the assessment of refrigerator safety knowledge, behavior for use before and after an intervention

Quantifying Aflatoxin B1 in peanut oil using fabricating fluorescence probes based on upconversion nanoparticles.

Rare earth doped upconversion nanoparticles convert near-infrared excitation light into visible emission light. Compared to organic fluorophores and semiconducting nanoparticles, upconversion nanoparticles (UCNPs) offer high photochemical stability, sharp emission bandwidths, and large anti-Stokes shifts. Along with the significant light penetration depth and the absence of autofluorescence in biological samples under infrared excitation, these UCNPs have attracted more and more attention on toxin detection and biological labelling. Herein, the fluorescence probe based on UCNPs was developed for quantifying Aflatoxin B1 (AFB1) in peanut oil. Based on a specific immunity format, the detection limit for AFB1 under optimal conditions was obtained as low as 0.2 ng·ml- 1, and in the effective detection range 0.2 to 100 ng·ml- 1, good relationship between fluorescence intensity and AFB1 concentration was achieved under the linear ratios up to 0.90. Moreover, to check the feasibility of these probes on AFB1 measurements in peanut oil, recovery tests have been carried out. A good accuracy rating (93.8%) was obtained in this study. Results showed that the nanoparticles can be successfully applied for sensing AFB1 in peanut oil.</p

Continuous statistical modelling for rapid detection of adulteration of extra virgin olive oil using mid infrared and Raman spectroscopic data

The main objective of this work was to develop a novel dimensionality reduction technique as a part of an integrated pattern recognition solution capable of identifying adulterants such as hazelnut oil in extra virgin olive oil at low percentages based on spectroscopic chemical fingerprints. A novel Continuous Locality Preserving Projections (CLPP) technique is proposed which allows the modelling of the continuous nature of the produced in-house admixtures as data series instead of discrete points. The maintenance of the continuous structure of the data manifold enables the better visualisation of this examined classification problem and facilitates the more accurate utilisation of the manifold for detecting the adulterants. The performance of the proposed technique is validated with two different spectroscopic techniques (Raman and Fourier transform infrared, FT-IR). In all cases studied, CLPP accompanied by k-Nearest Neighbors (kNN) algorithm was found to outperform any other state-of-the-art pattern recognition techniques

Impact of long-term storage at ambient temperatures on the total quality and stability of high-pressure processed tomato juice

High-pressure processing (HPP) can produce tomato juice of high quality and safety with a short shelf life under refrigeration temperatures. Long-term higher temperature storage studies are rare and temperature tolerant products are challenging to develop. The effect of high-pressure processing (HPP) on the total quality (colour, microbial counts, phytochemical levels, antioxidant and enzymatic activities) and stability (retention over time) of tomato juice during long-term storage was investigated. Thermal processing (TP) was used as a control treatment, and overall, two different ambient conditions (20 °C and 28 °C) were tested. Immediately after processing, HPP products proved superior to TP ones (enhanced redness, total carotenoids and lycopene, stable total phenols and inactivation of pectin methyl esterase). During initial storage (30 d) most quality attributes of HPP juice remained stable. Prolonged storage, however, led to losses of most quality attributes, although HPP (20 °C) showed lower quality degradation rate constants comparison to TP and HPP (28 °C). Industrial Relevance: There is a demand for ambient stable tomato products, especially in some parts of the world, and current industrial practices (canning, pasteurisation) either compromise in product quality or require refrigeration conditions. High-pressure processing has been investigated as milder technology, with a potential to deliver superior quality. The drawback is that is also requires chill storage. The results of this study show how quality parameters behave in a high-pressured tomato product and pave the way for further development that could optimise this technology. This could be of economic importance for the tomato juice industry to develop new products stable in ambient temperatures and perhaps beneficial for cutting down the refrigeration costs under specific conditions

Isolation of Salmonella from the egg-laying producing plant

Στην παρούσα εργασία διερευνήθηκε η παρουσία σαλμονελλών στο περιβάλλον τριών αυγοπαραγωγικών μονάδων της περιοχής Θεσσαλονίκη;. Εξετάστηκαν συνολικά 2.230 δείγματα αυγών, 588 δείγματα περιβάλλοντος χώρου (επιφάνειες δαπέδου, τοίχου, ιμάντων, σκευών και χώρων συσκευασίας), 168 δείγματα τροφής και 68 δείγματα νερού. Η έρευνα έδειξε ότι τα αυγά ήταν μολυσμένα σε ποσοστό από 0,29 έως 3,29% (μ.ο. 1,65%). Οι επιφάνειες περιβάλλοντος χώρου εκτροφής των ορνίθων και χώρου του συσκευαστηρίου ήταν μολυσμένες σε ποσοστό 6,81% και 7,58% αντίστοιχα. Η τροφή ήταν μολυσμένη σε ποσοστό από 0% έως 6,6% (μ.ό. 4,2%), ενώ όλα τα δείγματα νερού ήταν απαλλαγμένα από σαλμονέλλες. Απομονώθηκαν συνολικά 86 στελέχη σαλμονέλλων που ανήκαν στους ορότυπους S. enteritidis(ποσοστό 76,8%), S. bredeney(20,9%) και S. Heidelberg (2,3%). Η υψηλή παρουσία της S. enteritidis, σε σχέση με τους άλλους ορότυπους, στα αυγά, στο περιβάλλον και στην τροφή των πουλερικών έδειξε ότι πρέπει να λαμβάνονται αυστηρά μέτρα πρόληψης της μόλυνσης για την προστασία της Δημόσιας Υγείας και της διασποράς των σαλμονελλών στο περιβάλλον.In the present paper, the presence of Salmonella spp. in the egg-laying hens producing plants in Thessaloniki area was studied. In total, 2.230 eggshell samples, 588 samples surfaces from floor, walls, conveyor belts, utensils and packaging areas, 168 feed samples and 68 water samples were examined. The survey showed that the rate of contamination in the eggshells was 0.29-3.29% (mean value 1.65%). The contamination rate of the surrounding area of the cages (floor, walls, conveyor belts) and the surfaces in the packaging areas were 6.81% and 7.58% respectively. The feed was contaminated at a rate of 0-6.6% (mean value 4.2%), while all the water samples were free of Salmonella spp. Eighty-six strains of Salmonella were isolated belonging to the S. enteritidis serotype (76.8%), S. bredeney (20.29%) and S. Heidelberg (2,3%). The high prevalence of S. enteritidis, in contrast to the other serotypes, isolated from the eggshells, from the area of the egg producing plants and the feed, showed that strict preventive measures should be applied for the protection of public health and the avoidance of dispersion of Salmonella in the environment

Survival of Escherichia coli 0157:H7 in Feta cheese during storage

Η επιβίωση της Escherichia coli 0157:Η7 σε τυρίφέτα και στην άλμη της μελετήθηκε στη διάρκεια της συντήρησηςστους 4°C και 12°C. Η επιμόλυνση του τυριού έγινε με την προσθήκη5.3 log10CFU/ml της Ε. coli Ol57:Η7 στην άλμη. Η E. Coli0157:Η7 ήταν ανιχνεύσιμη στην άλμη με ενοφθαλμισμό στο υπόστρωμαSMAC μέχρι την 40η και 32η μέρα κατά τη συντήρηση τηςστους 4°C και 12°C αντίστοιχα, ενώ έπειτα απο εμπλουτισμό καιστη συνέχεια σπορά στο υπόστρωμα SMAC μέχρι την 44η και 36ημέρα στους 4°C και 12°C αντίστοιχα. Η E. coli 0157:Η7 στη φέταήταν ανιχνεύσιμη στο υπόστρωμα SMAC μέχρι την 44η και 38η μέρακατά τη συντήρηση στους 4°C και 12°C, ενώ έπειτα απο εμπλουτισμόκαι στη συνέχεια σπορά στο υπόστρωμα SMAC μέχριτην 50η και 42η μέρα στους 4°C και 12°C αντίστοιχα. Τα αποτελέσματαέδειξαν ότι η Ε. coli Ol57:Η7 επέζησε για μεγαλύτερο διάστημαστη φέτα από ότι στην άλμη και για τις δυο θερμοκρασίεςσυντήρησης αν και η διαφορά αυτή ήταν μικρή. Η επιβίωση της Ε.co/i0157:H7 τόσο στη φέτα όσο και στην άλμη ήταν μεγαλύτερηστους 4°C παρά στους 12°C .The survival of E. co/i0157:H7 in Feta cheese and the brine used after 2 months ripening of cheese, was studied during storage at 4°C and 12°C. An inoculum of 5.3 log10CFU/ml of E. coli Ol57:H7 was added in brine, for the contamination with the pathogen of Feta cheese. E. coli Ol 57:H7 was detectable in brine by direct plating on SMAC up to 40th day and 32th day during its storage at 4°C and 12°C respectively, while by enrichment and following plating on SMAC up to 44th day (4°C) and 36th day (12°C). The E. coli 0157:H7 was detectable in Feta by direct plating on SMAC up to 44th day (4°C) and 38th day (12°C), while by enrichment and following plating on SMAC up to 50th day (4°C) and 42th day (12°C). The results showed that E. coli Ol57:H7 survived longer in Feta than in its brine, for both storage temperatures but the difference was very low. The survival of E. coli 0157:H7 in feta and brine was longer during the storage at 4°C than at 12°C