Effect of Low Temperature-Long Time Blanching on Quality of Dried Sweet Potato

ABSTRACT

Combining low temperature, long time blanching with moderate temperature drying very positively affected the textural characteristics of dehydrated sweet potato. Ten mm cubes of this tuber were slow-blanched at 60, 65 and 70°C for 15 and 45 minutes, then conventionally blanched at 94°C three minutes and, finally dehydrated in a cabinet dryer at 70 and 8S°C for a maximum of 195 minutes. The final product showed optimum texture attributes for the blanching treatment of 65°C for 15 minutes followed by the flash blanching and the drying process at 70°C for 120 minutes.     

A heuristic control strategy for non-linear reaction-diffusion equations

A heuristic control strategy is proposed to control the speed of a wave front that is governed by a one-dimensional advection-diffusion-reaction equation. The strategy employs the time-dependent temperatures measured by two sensors located at different positions. These temperatures are used to vary the wave speed in such a manner that the wave front is located between the two sensors. Results are presented for different sensor locations and time constants arid show that the control strategy drives the wave front to its analytic solution.     

Effects of changes during ripening and frozen storage on the physicochemical and sensory characteristics of Cabrales cheeses

The physicochemical and organoleptic characteristics of two batches of Cabrales cheese, stored at −20°C for 4 and 8 months, respectively, were studied during subsequent ripening. Frozen storage did not result in significant alterations in overall compositional, rheological and sensory properties or the level of lipolysis. The extent of proteolysis was slightly lower in the cheeses frozen prior to ripening.     

β-hydroxyacyl-CoA-dehydrogenase (HADH) differentiates unfrozen from frozen-thawed crawfish (Procambarus clarkii) and trout (Salmo gairdneri) meat

An enzymatic method for differentiation of unfrozen from thawed crawfish ( Procambarus clarkii ) and trout ( Salmo gairdneri ) has been developed. The method is based on the release of the β-hydroxyacyl-CoA-dehydrogenase (HADH) during freezing. The HADH activity mean values were 7.9 and 78.9 for unfrozen and thawed trout, respectively. In the case of crawfish, these values were 12 and 70 respectively. Statistical analyses showed significant differences ( P 0.001) in both species. Trout could be distinguished with a high confidence level, but for crawfish this level was slightly lower.     

Queso Chihuahua: effects of seasonality of cheesemilk on rheology†

Fresh semihard raw milk (RM) and pasteurized milk (PM) cheeses made by Mennonite communities in Chihuahua, Mexico were sampled in early winter, mid‐spring and late summer and evaluated during storage to determine if rheological properties were affected by the season the cheese was produced. Seasonal effects were observed in the rheology of the RM cheeses, which underwent more extensive proteolysis than the PM cheeses. The rheological properties of the PM cheeses and the composition of all cheeses were consistent throughout the year. The texture of the RM cheese is affected by season, whereas the variability in texture and composition of PM cheese is minimal, allowing for the manufacture of a uniform product.     

Preliminary studies towards utilization of various plant extracts as antisolar agents

The aim of this work was to evaluate several plant extracts with regard to ultraviolet absorption spectra in view of a possible application as antisolar agents. Liquid and dry extracts of Hamamelis virginiana, Matricaria recutita, Aesculus hippocastanum, Rhamnus purshiana and Cinnamomum zeylanicum were prepared by repercolation, maceration and microwave oven extraction. UVB absorption spectra (290–320nm) were obtained and the solar protection factors (SPF) of these preparations were determined by a spectrophotometric method. The results showed that after incorporation to a 2% solution of the synthetic sunscreen octylmethoxycinnamate, the extracts showed an intensification in SPF values, suggesting that this can be an interesting method to intensify SPF. In addition, these extracts can contribute their emollient and moistening properties to the product. These are important characteristics for protecting skin against exposure to the sun.     

Heat Pipe Design Through Generalized Extremal Optimization

In this paper, an application of the Generalized Extremal Optimization (GEO) algorithm to the optimization of a heat pipe (HP) for a space application is presented. The GEO algorithm is a generalization of the Extremal Optimization (EO) algorithm, devised to be applied readily to a broad class of design optimization problems regardless of the design space complexity it would face. It is easy to implement, does not make use of derivatives, and can be applied to either unconstrained or constrained problems with continuous, discrete, or integer variables. The GEO algorithm has been tested in a series of test functions and shows to be competitive to other stochastic algorithms, such as the Genetic Algorithm. In this work, it is applied to the problem of minimizing the mass of an HP as a function of a desirable heat transport capability and a given temperature on the condenser. The optimal solutions were obtained for different heat loads, heat sink temperatures, and three working fluids: ammonia, methanol, and ethanol. The present design application highlights the GEO features of being easily implemented and efficient on tackling optimization problems when the objective function presents design variables with strong nonlinear interactions and is subject to multiple constraints.     

A combination of stereological methods,biochemistry and electron microscopy for the investigation of drug treatment effects in experimental animals

Some chemotherapeutic agents used for breast cancer (BC) treatment can induce severe side effects in the ovarian tissue. The combination of cyclophosphamide and docetaxel (TC) is widely used for BC treatment; however, its late effects in the ovary are not completely understood. The main purpose of this study was to evaluate the structural and ultrastructural alterations in the ovarian stroma induced by TC treatment. Wistar rats were divided into two groups: a control group and a TC group. They were euthanized 5 months after the end of treatment, and their plasma and ovaries were collected. Important alterations were noted. The serum estradiol level was significantly reduced in the TC group compared with the control group. Additionally, the number of apoptotic nuclei was higher in the TC group. The role of the inflammatory response in the development of ovarian damage was investigated, and we found an increased number of mast cells and increased expression of TNF‐α in the TC group. The involvement of fibrosis was also investigated. The results showed that the TC group had increased expression levels of TGF‐β1, collagen type I (col‐I) and collagen type III (col‐III) compared with the control group. Ultrastructural analysis revealed the presence of collagen fibrils in the treated group and illustrated that the ovarian tissue architecture was more disorganized in this group than in the control group. The results from this study are important in the study of chemotherapy‐induced ovarian failure and provide further insight into the mechanisms involved in the development of this disease.     

Phytoplankton pigment patterns in the Canary Islands area as determined using Coastal Zone Colour Scanner data

Abstract

Data from the Nimbus-7 Coastal Zone Colour Scanner (CZCS) were analyzed to determine the phytoplankton pigment patterns in the ocean surrounding the Canary Islands. Two different pattterns were observed in this region. One pattern was associated with the influence of the northwest African coastal upwelling system on the ocean surrounding the Canary Islands and the other was associated with individual islands, probably due to the disruptive effect of the Canary Islands on the flow of the Canary Current