SLIP MELTING POINT ESTIMATION OF FAT BLENDS BEFORE AND AFTER INTERESTERIFICATION BASED ON THEIR FATTY ACID COMPOSITIONS

In this study the relationship between slip melting point (SMP) and fatty acid composition of blends before and after interesterification were investigated. Forty-four blends were prepared using sunflower, canola and cottonseed oils as well as palm stearin and/or fully hydrogenated palm stearin in different proportions. Fatty acid compositions and SMP of samples were determined and then SMP of the blends before and after interesterification were defined as a function of five fatty acids. Specific constants of C_16:0, C_18:0, C_18:1, C_18:2 and C_18:3 fatty acids were determined as 0.455, 0.821, 0.622, 0.215 and -1.653, respectively, for the blends before interesterification and 0.532, 0.614, 0.399, 0.055 and -2.471, respectively, for the blends after interesterification by using least squares method. Slip melting point of blends were calculated using these constants and fatty acid compositions and then compared with the experimental values. No linear relationship existed between the calculated and experimental results of the blends before interesterification, but SMP of the blends after interesterification could be estimated with high (r=0.956) accuracy.     

Experimental investigation of FMS machine and AGV scheduling rules against the mean flow-time criterion

Although a significant amount of research has been carried out in the scheduling of flexible manufacturing systems (FMSs), it has generally been focused on developing intelligent scheduling systems. Most of these systems use simple scheduling rules as a part of their decision process. While these scheduling rules have been investigated extensively for a job shop environment, there is little guidance in the literature as to their performance in an FMS environment. This paper attempts to investigate the performances of machine and AGV scheduling rules against the mean flow-time criterion. The scheduling rules are tested under a variety of experimental conditions by using an FMS simulation model.     

An investigation of some properties of banana yogurts made with commercial ABT-2 starter culture during storage

Five yogurt batches were prepared with banana puree and sugar combinations and ABT-2 ( Streptococcus salivarius ssp. thermophilus, Lactobaccilus acidophilus and Bifidobacterium spp.) as starter culture. The addition of fruit influenced ( P <  0.05) the syneresis, titratable acidity and pH, whereas the viscosity value, and S. salivarius ssp. thermophilus, L. acidophilus and Bifidobacterium spp. counts were found to be insignificant. Storage time significantly ( P <  0.05) affected the syneresis, titratable acidity, pH value, and S. salivarius ssp. thermophilus counts, while the viscosity value and L. acidophilus and Bifidobacterium spp. counts were not affected. The sensory evaluations showed that the sample B was most preferred by panellists.     

PREDICTION OF GROWTH OF BACILLUS PUMILUS AS AFFECTED BY SPORE LOAD AND CHLORHEXIDINE ACETATE CONCENTRATION

The influence of the microbial contamination load (xl) and preservative concentration (x2), as predictor variables, on the percentage of vials with growth of B. pumilus spores (y) was studied. The effect of a wide range of spore loads (1-500,000 spores of B. pumilus per sample) and preservative (chlorhexidine acetate) concentrations (0.03–40 μg/ml) on the percentage of contaminated samples was determined. Each contamination load was studied by adding the specified number of spores to vials containing various concentrations of chlorhexidine dissolved in 2 ml of nutrient broth. Every level of spore and chlorhexidine concentration was represented by 50 or 100 vials. Curves representing the number of contaminated vials against the concentration of chlorhexidine were sigmoidal in shape and the data showed an indirect relationship. Data were analyzed by the regression analysis which revealed a significant correlation (R=0.83) with the regression equation:     

Effect of non-enzymatic glycation on collagen nanoscale mechanisms in diabetic and age-related bone fragility

Age and diabetes have long been known to induce an oxidative reaction between glucose and collagen, leading to the accumulation of advanced glycation end-products (AGEs) cross-links in collagenous tissues. More recently, AGEs content has been related to loss of bone quality, independent of bone mass, and increased fracture risk with aging and diabetes. Loss of bone quality is mostly attributed to changes in material properties, structural organization, or cellular remodeling. Though all these factors play a role in bone fragility disease, some common recurring patterns can be found between diabetic and age-related bone fragility. The main pattern we will discuss in this viewpoint is the increase of fibrillar collagen stiffness and loss of collagen-induced plasticity with AGE accumulation. This study focused on recent related experimental studies and discusses the correlation between fluorescent AGEs content at the molecular and fibrillar scales, collagen deformation mechanisms at the nanoscale, and resistance to bone fracture at the macroscale.