Effect of cooking and smoking methods on proximate composition, lipid oxidation and mineral contents of Polypterus bichir bichir fish from far-north region of Cameroon.

The objective of this study was to evaluate the effect of different cooking and smoking treatments on proximate composition, lipid quality and mineral content of Polypterus bichir bichir, a fish consumed in Far-North Region of Cameroon. Results revealed that the proximate composition was significantly (P < 0.05) affected by treatments: except boiling, all the others treatment reduced significantly (P < 0.05) moisture content of fish while lipid and protein were significantly increased. After processing, the free fatty acids, peroxide and thiobarbituric acid reactive substances values (TBARS) were increased. Iodine value of all treated samples was significantly (P < 0.05) decreased. The combined treatments (frying + boiling and smoking + boiling) negatively affected the lipid quality of fish. Boiling caused significant losses in the mineral contents of fish while smoking treatment led to an important increase of its mineral contents. Steaming appeared to be the best processing method for cooking fish concerning the lipid stability.

Effect of different pre-boiling treatment on in vitro protein and amino acid digestibility of mung beans [Vigna radiata (L.) Wilczek]

@#Introduction: Mung beans [Vigna radiata (L.) Wilczek] are good sources of protein. Nevertheless, its protein quality is still questionable. This study aimed to determine the effect of different processes prior to boiling, on the in vitro protein and amino acid digestibility of mung beans by using a 6-hour enzymatic digestion. Methods: This study was based on the household method of the processes before boiling including unsoaking, soaking, and dehulling. Products from all treatment methods were analysed for proximate composition (moisture, crude protein, crude fat, ash, and dietary fibre) on a dry basis, naturally occurring anti-nutritional factors, amino acid composition, and digestibility of protein and amino acids. The amino acid composition and amino acid digestibility were used to calculate the dietary protein quality. Results: The treatments prior to the boiling of mung beans such as dehulling, soaking and without soaking, improved protein digestibility significantly by 10.8%, 10.3%, and 12.0%, respectively, when compared with that of raw mung beans (37.9%). Of the different mung bean pre-treatments, soaking seems to have the highest value of average indispensable amino acid (IAA) digestibility (55.4%), in particularly branched-chain amino acids (66.4%). However, there was no difference in the protein quality in terms of digestible indispensable amino acid score (DIAAS) across different treatment groups. Conclusion: The different processes performed on mung bean before boiling had only a slight impact on its amino acid digestibility and they rarely affected DIAAS values.

Physico-Chemical and Structural Characteristics of Vegetables Cooked Under Sous-Vide, Cook-Vide, and Conventional Boiling.

In this paper, physico-chemical and structural properties of cut and cooked purple-flesh potato, green bean pods, and carrots have been studied. Three different cooking methods have been applied: traditional cooking (boiling water at 100 °C), cook-vide (at 80 and 90 °C) and sous-vide (at 80 °C and 90 °C). Similar firmness was obtained in potato applying the same cooking time using traditional cooking (100 °C), and cook-vide and sous-vide at 90 °C, while in green beans and carrots the application of the sous-vide (90 °C) required longer cooking times than cook-vide (90 °C) and traditional cooking (100 °C). Losses in anthocyanins (for purple-flesh potatoes) and ascorbic acid (for green beans) were higher applying traditional cooking. ß-Carotene extraction increased in carrots with traditional cooking and cook-vide (P < 0.05). Cryo-SEM micrographs suggested higher swelling pressure of starch in potatoes cells cooked in contact with water, such as traditional cooking and cook-vide. Traditional cooking was the most aggressive treatment in green beans because the secondary walls were reduced compared with sous-vide and cook-vide. Sous-vide preserved organelles in the carrot cells, which could explain the lower extraction of ß-carotene compared with cook-vide and traditional cooking. Sous-vide cooking of purple-flesh potato is recommended to maintain its high anthocyanin content. Traditional boiling could be recommended for carrots because increase ß-carotenes availability. For green beans, cook-vide, and sous-vide provided products with higher ascorbic acid content.

Survival of Salmonella Typhimurium in poultry-based meat preparations during grilling, frying and baking.

The burden of food-borne diseases still represents a threat to public health; in 2012, the domestic setting accounted for 57.6% of strong-evidence EU food-borne Salmonella outbreaks. Next to cross-contamination, inadequate cooking procedure is considered as one of the most important factors contributing to food-borne illness. The few studies which have assessed the effect of domestic cooking on the presence and numbers of pathogens in different types of meat have shown that consumer-style cooking methods can allow bacteria to survive and that the probability of eating home-cooked poultry meat that still contains surviving bacteria after heating is higher than previously assumed. Thus, the main purpose of this study was to reproduce and assess the effect of several types of cooking treatments (according to label instructions and not following label instructions) on the presence and numbers of Salmonella Typhimurium DT 104 artificially inoculated in five types of poultry-based meat preparations (burgers, sausages, ready-to-cook-kebabs, quail roulades and extruded roulades) that are likely to be contaminated by Salmonella. Three contamination levels (10 cfu/g; 100 cfu/g and 1000 cfu/g) and three cooking techniques (grilling, frying and baking) were applied. Cooking treatments performed according to label instructions eliminated Salmonella Typhimurium (absence per 25g) for contamination levels of 10 and 100 cfu/g but not for contamination levels of 1000 cfu/g. After improper cooking, 26 out of 78 samples were Salmonella-positive, and 23 out of these 26 samples were artificially contaminated with bacterial loads between 100 and 1000 cfu/g. Nine out of 26 samples provided quantifiable results with a minimum level of 1.4MPN/g in kebabs (initial inoculum level: 100 cfu/g) after grilling and a maximum level of 170MPN/g recorded in sausages (initial inoculum level: 1000 cfu/g) after grilling. Kebabs were the most common Salmonella-positive meat product after cooking, followed by sausages, burgers and extruded roulades; in relation to the type of cooking treatment applied, Salmonella Typhimurium was detected mostly after frying. Thus, following label instructions mostly, but not always, produced safe cooked poultry-based meat preparations, while the application of inadequate cooking treatments was not able to assure complete elimination of Salmonella from the products even with a low contamination level (10cfu/g). Consequently, there is a need to develop guidelines for producers and consumers and promote a multidisciplinary educational campaign in order to provide information on safe cooking and time-temperature combinations able to maintain the organoleptic qualities of meat.