Electronic nose for microbial quality classification of grains

The odour of grains is in many countries the primary criterion of fitness for consumption. However, smelling of grain for quality grading should be avoided since inhalation of mould spores or toxins may be hazardous to the health and determinations of the off-odours are subjective. An electronic nose, i.e. a gas sensor array combined with a pattern recognition routine might serve as an alternative. We have used an electronic nose consisting of a sensor array with different types of sensors. The signal pattern from the sensors is collected by a computer and further processed by an artificial neural network (ANN) providing the pattern recognition System. [1]

Influence of high pressure on the color and microbial quality of beef meat

An experimental design was used to study the effect of various pressure values (50–600 MPa) and holding times (20–300 s) on color and microbiological quality of bovine muscle (Biceps femoris). The experiments were conducted at 10°C. The pressure intensity is more significant than holding time for redness, total color difference and metmyoglobin content. Pressure higher than 300 MPa induces modifications of meat color parameters such a decrease of the total color difference (ΔE), a decrease in the total flora and a 1 week delay before microbial growth (520 MPa, 260 s). During the first 3 days of storage (4°C), the increase in redness is maintained for the 130 MPa samples while the redness of the 520 MPa samples decreases gradually, in relation to the increase of metmyoglobin. The cooking (1 h at 65°C) done after pressurization led to the disappearance of color differences observed between the nontreated and pressurized samples. [2]

Effect of cyclic exposure to ozone gas on physicochemical, sensorial and microbial quality of whole and sliced tomatoes

The effect of a humidified flow of ozone-enriched air applied cyclically (4 ± 0.5 μL L−1 of O3 for 30 min every 3 h) on metabolic behaviour and sensorial and microbial quality of whole and fresh-cut ‘Thomas’ tomatoes stored up to 15 days at 5 °C was examined. The application of O3 initially stimulated the respiration rate in a way similar to a stress, although after 2 days, the metabolic activity decreased to a rate lower than that of control (air flow). In O3-treated whole and sliced tomatoes a higher sugar (fructose and glucose) and organic acid (ascorbic and fumaric) content was found. The kind of cut (whole or slices) did not affect the sensitivity of tomato to O3. In whole tomatoes, O3 maintained the tissue firmer than in control fruit while no influence was found on slices. The O3 treated fruit retained a good appearance and overall quality in slices but experienced a reduced aroma. Also, O3 substantially reduced microbial counts, being more noticeable on bacteria (1.1–1.2 log10 units) than on fungi (0.5 log10 units). This effect was higher when the storage time was longer and when a higher O3 level (7 μL L−1) was used. O3 did not cause any damage or off-flavour in slices or whole tomatoes. In conclusion, the assayed O3 treatment can be useful for maintaining quality and reducing microbial populations in whole and sliced tomato. [3]

Health-related Microbial Quality of Drinking Water in Kangavar, Western Iran

Evaluation of the microbial quality of drinking water can prevent the water-borne diseases outbreak that is one of the most important challenges in the world. Therefore, the aim of this study was to assess the seasonal variation of water-borne diseases prevalence associated with the microbial quality of drinking water and the comparison between rural and urban areas in Kangavar city, west of Iran. To accomplish this study, the results of the microbial quality of drinking water and cases of simple diarrhea, dysentery, typhoid and hepatitis A were received from all rural and urban health centers of the city during five years (2006-2010). To determine the relationship between diseases and microbial quality of water, Correlation instruction and Pearson correlation coefficient were used. The results showed that except hepatitis A, the incidence of all diseases in different areas (urban or rural) and seasons had significant relationship with microbial contamination of drinking water (P-value<0.05). The stronger relationship was observed in rural areas than in urban areas (except simple diarrhea) and in warm seasons than in cold seasons. With respect to the impact of the microbial quality of water on the incidence of dysentery and typhoid diseases, keeping up the quality of drinking water in places and times with high sensitivity (rural areas and warm seasons) should be considered strongly. [4]

Evaluation of Nutritional and Microbial Quality of Three Varieties of Dankuwa: A Nigerian Cereal Snack

Aims: This study addresses the issue of diversification of dankuwa in order to increase its nutritional quality and to determine the nutritional and microbial load of dankuwa sold by vendors and laboratory produced dankuwa.

Study Design: To produce dankuwa using other cereal such as millet and sorghum and to determine the nutritional content, sensory properties and microbial load of commercial dankuwa and laboratory produced dankuwa.

Place and Duration of Study: Samples were purchased from vendors in Bida Local Government, Nigeria. Analyze at Central Services Laboratory of National Cereal Research Institute, Badeggi, Niger State. Experiment was conducted between November 2013 and March 2014.

Methodology: In this study, three samples of dankuwa cereal were used. Two samples were laboratory processed using sorghum or millet and the third sample was purchased from vendors. The various dankuwa samples were analysed to determine their nutritional quality, sensory properties and microbial properties at Central Services Laboratory of National Cereal Research Institute Badeggi, Bida Niger State. Results obtained were subjected to statistical analysis. [5]

Reference

[1] Jonsson, A., Winquist, F., Schnürer, J., Sundgren, H. and Lundström, I., 1997. Electronic nose for microbial quality classification of grains. International Journal of Food Microbiology, 35(2), pp.187-193.

[2] Jung, S., Ghoul, M. and de Lamballerie-Anton, M., 2003. Influence of high pressure on the color and microbial quality of beef meat. LWT-food science and technology, 36(6), pp.625-631.

[3] Aguayo, E., Escalona, V.H. and Artés, F., 2006. Effect of cyclic exposure to ozone gas on physicochemical, sensorial and microbial quality of whole and sliced tomatoes. Postharvest Biology and Technology, 39(2), pp.169-177.

[4] Mirzaei, N., Nourmoradi, H., Javid, A., Mohammadi-Moghadam, F., Ghaffari, H.R., Ahmadpour, M. and Sharafi, K., 2016. Health-related microbial quality of drinking water in Kangavar, Western Iran. Journal of Advances in Medicine and Medical Research, pp.1-7.

[5] Okeke, K.S., Bello, Z.A. and Akoma, O., 2014. Evaluation of Nutritional and Microbial Quality of Three Varieties of Dankuwa: A Nigerian Cereal Snack. Current Journal of Applied Science and Technology, pp.4558-4565.

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