THERMAL INACTIVATION OF SALMONELLA ENTERITIDIS BY BOILING AND FRYING EGG METHODS

Salmonella enteritidis was cultivated in egg yolks and submitted to boiling and frying methods commonly used in domestic conditions in the south of Brazil. The results have demonstrated a rapid growth of the microorganism reaching counts of 9.0 log₁₀at 168 h. When contaminated shell eggs were placed in water and slowly heated, a population of approximately 7.0 log₁₀was completely inactivated after boiling for 1 min. However, in eggs placed directly in boiling water, the reduction was only 1.35 log₁₀after 1 min, and the entire population was eliminated after 3 min. A reduction of approximately 2.78 log₁₀was observed after frying for 1.5, 2.0 and 2.5 min. Even though the solidification of yolk has been pointed out as an indicator of S. enteritidis elimination in egg yolks, attention should be given to frying procedures, as considerable high levels of this microorganism could be recovered even from solidified yolks.     

CHEMICAL COMPOSITION OF OIL FROM COULA EDULIS (Bail.) NUTS

Coula edulis (Bail.) nuts are generally used as food components in the littoral and southern part of Cameroon. The physicochemical characteristics, the fatty acids and the triacylglycerols (TGs) of Coula edulis (Bail.) nut oil from two different agroclimatical zones of Cameroon were studied. The oil content varied according to the zone (33.50 – 36.65%). The iodine value (90 – 95), saponification value (180 – 185) and the nitrogen (2.16 – 2.40%), and ash (2.5 to 2.7%) contents were similar for the two types of nuts studied. The main fatty acid of the oil was oleic acid (95.5 – 97.4%), as determined by capillary gas chromatographic analysis. The triacylglycerol profile obtained by reversed phase liquid     

A comparison of control charting procedures for monitoring process dispersion

We consider several control charts for monitoring normal processes for changes in dispersion. We present comparisons of the average run length performances of these charts. We demonstrate that a CUSUM chart based on the likelihood ratio test for the change point problem for normal variances has an ARL performance that is superior to other procedures. Graphs are given to aid in designing this control chart.     

Improved p charts to monitor process quality

It is a common practice to monitor the fraction p of non-conforming units to detect whether the quality of a process improves or deteriorates. Users commonly assume that the number of non-conforming units in a subgroup is approximately normal, since large subgroup sizes are considered. If p is small this approximation might fail even for large subgroup sizes. If in addition, both upper and lower limits are used, the performance of the chart in terms of fast detection may be poor. This means that the chart might not quickly detect the presence of special causes. In this paper the performance of several charts for monitoring increases and decreases in p is analyzed based on their Run Length (RL) distribution. It is shown that replacing the lower control limit by a simple runs rule can result in an increase in the overall chart performance. The concept of RL unbiased performance is introduced. It is found that many commonly used p charts and other charts proposed in the literature have RL biased performance. For this reason new control limits that yield an exact (or nearly) RL unbiased chart are proposed.     

CHEMICAL COMPOSITION OF OIL FROM TETRACARPIDIUM CONOPHORUM ((MÜLL. ARG.) HUTCH. AND DALZ.) NUTS

Tetracarpidium conophorum is known in the littoral and the western Cameroon as kaso or ngak and serves as an edible nut eaten between meals. The physicochemical characteristics, the fatty acids and the triacylglycerols (TG) of T. conophorum nut oil (Type 1 and Type 2) from the southern continental low lands were studied. The oil content varied between 55.75 and 61.62%. The iodine value (180–182), saponification value (175–176) and nitrogen (8.08–8.78) were similar. Ashes varied between 8.40 and 9.68%. The main fatty acid of the golden yellow was linolenic acid (69.47–70.39%) as determined by capillary gas chromatographic analysis. The triacylglycerol profil obtained by reversed phase liquid chromatography showed 10 TG with three major ones identified as     

Quaternary Ammonium Compounds Inhibit and Reduce the Attachment of Viable Salmonella typhimurium to Poultry Tissues

Quaternary ammonium compounds (QAC) were studied to characterize their inhibition and reversal of S. typhimurium's strong attachment to chicken skin. An initial screening human buccal epithelial cell model and a novel, highly quantitative model using pieces of chicken skin in culture plates were used. Some QAC, particularly cetylpyridinium chlo ride (CPC), were extremely effective at both inhibiting and reversing attachment of viable S. typhinlurium to chicken skin. Pretreatment of chicken skin (room temperature, 10 min) with 0.1% CPC completely inhibited the attachment of S. typhimurium. CPC may be very beneficial in reducing S. typhimurium contamination of poultry carcasses during processing and especially in preventing cross-contamination.     

Identification of Key Textural Attributes of Viscoelastic Syrups By Regression Analysis

Regression analysis was used to identify key textural attributes in the sensory evaluation of table syrups with varying viscoelastic properties. The syrups were sensorily evaluated in the mouth, while being poured out of a bottle and while the syrup was spreading on a flat surface. The triplet “Viscous,”“Smooth,” and “Slippery” gave the best average coefficient of determination (R²) in the mouth; the triplet “Watery,”“Even,” and “Drippy” gave the best R² for pouring; and the triplet “Viscous,”“Even,” and “Smooth” the best R² for spreading. The results suggested that there were significantly different texture perception cues in the three different evaluation procedures.