Vacuum impregnation of apple slices with Yacon (Smallanthus sonchifolius Poepp. & Endl) fructooligosaccharides to enhance the functional properties of the fruit snack

This work aimed to incorporate prebiotic FOS from yacon in apple slices using vacuum impregnation (VI). Three FOS concentrations (10.3, 14.1 and 18.9 g per 100 g of dry matter (DM)), two temperatures (25 and 35 °C), reuse of extracts and stability of the impregnated slices were evaluated. The highest impregnation level (30.5 g per 100 g DM) was obtained at 35 °C with 14.1% FOS extract while levels of common sugars were reduced. Total phenolics and ABTS antioxidant capacity (AC) slightly decreased while ORAC AC was reduced by 55%. Reuse of the impregnation solution in successive cycles after restoring the FOS level maintained the FOS concentration and profile (GF2–GF7), sugars and phenolic antioxidants. FOS in apple slices remained stable during 4 week storage, while a_w, colour and fracture point changed during storage. This work demonstrated the feasibility of yacon FOS to improve the functional properties of dehydrated apple slices.     

Guest editorial for the theme section on modeling language engineering

Software and Systems Modeling -     

A variable neighborhood search simheuristic for the multiperiod inventory routing problem with stochastic demands

The inventory routing problem (IRP) combines inventory management and delivery route‐planning decisions. This work presents a simheuristic approach that integrates Monte Carlo simulation within a variable neighborhood search (VNS) framework to solve the multiperiod IRP with stochastic customer demands. In this realistic variant of the problem, our goal is to establish the optimal refill policies for each customer–period combination, that is, those individual refill policies that minimize the total expected cost over the periods. This cost is the aggregation of both expected inventory and routing costs. Our simheuristic algorithm allows to consider the inventory changes between periods generated by the realization of the random demands in each period, which have an impact on the quantities to be delivered in the next period and, therefore, on the associated routing plans. A range of computational experiments are carried out in order to illustrate the potential of our simulation–optimization approach.     

Heterogeneous SoC-based acceleration of MPEG-7 compliance image retrieval process

With the growing amount of multimedial content over the internet and broadcast systems, mechanisms for efficient information organization, manipulation and transmission are becoming indispensable. Optimization of the multimedia search and retrieval processes is nowadays an important area of development due to the difficulty to browse, filter and manage that big amount of data. The adoption of the MPEG-7 standard has a significant importance to simplify the image retrieval process. However, performance issues are still relevant when the retrieval must be accomplished in real time. This work presents an innovative and efficient approach of a Content-Based Retrieval Process using metric spaces implemented in heterogeneous resources according to the demand of computational power. Several implementations were made and comparative results are shown evidencing the benefits of the proposed approach.     

Optimisation of extraction conditions and thermal properties of protein from the Andean pseudocereal cañihua (Chenopodium pallidicaule Aellen)

Response surface methodology (RSM) was used to optimise alkaline protein extraction from cañihua grain meal as to maximise protein extraction yield. Different factors (temperature, extraction time, solvent/meal ratio, pH and NaCl molar concentration) were screened, and their significant influence on the extracted protein yield was evaluated. The first four factors were selected and studied by RSM using a central composite design (CCD). The obtained model produced a satisfactory fitting of the results (R² = 0.801). Optimal cañihua protein extraction conditions corresponded to a temperature of 21 °C, time extraction of 5 min, solvent/meal ratio of 37/1 (v/w) at pH 10 resulting in a protein yield of 80.4 ± 1.3%, which closely agree with the predicted value of 81.4%. Moreover, protein degradation was studied via differential scanning calorimetry (DSC) obtaining a denaturation temperature of 93.4 °C and an enthalpy value of 1.22 ± 0.05 J g^?1. These results are interesting from a technological point to help in designing an optimal protein extraction process and cañihua food processing strategies.     

Preparation of quercetin glucuronides and characterization by HPLC–DAD–ESI/MS

Quercetin is the main flavonol in the human diet, and the most commonly used in studies of biological activity. The major circulating forms of quercetin found in the human plasma after consumption of food containing distinct quercetin glycosides are glucuronides and sulfates. In this work quercetin glucuronides have been obtained from green beans (quercetin 3-glucuronide) and by enzymic synthesis (quercetin 4′-glucuronide) using a modification of the method described by Plumb et al. (Methods in polyphenol analysis, The Royal Society of Chemistry, Cambridge, pp 187, 2003) so as to improve the original low yields of that methodology. The method finally optimised got yields of 19% in the preparation of quercetin 4′-glucuronide, which allows its further isolation for their use in biological assays. In addition, quercetin 3′-glucuronide, 3-glucuronide and a diglucuronide were synthesised with lower yields. The compounds prepared have been employed to perform assays in order to obtain data for their identification by HPLC coupled to photodiode array detection and tandem mass spectrometry. It was observed that the analysis by HPLC–ESI/MS/MS could allow the identification of different quercetin glucuronides based on the presence of some minor key MS² fragments.     

Metabolic Signature of Energy Metabolism Alterations and Excess Nitric Oxide Production in Culture Media Correlate with Low Human Embryo Quality and Unsuccessful Pregnancy

Notwithstanding the great improvement of ART, the overall rate of successful pregnancies from implanted human embryos is definitely low. The current routine embryo quality assessment is performed only through morphological criteria, which has poor predictive capacity since only a minor percentage of those in the highest class give rise to successful pregnancy. Previous studies highlighted the potentiality of the analysis of metabolites in human embryo culture media, useful for the selection of embryos for implantation. In the present study, we analyzed in blind 66 human embryo culture media at 5 days after in vitro fertilization with the aim of quantifying compounds released by cell metabolism that were not present as normal constituents of the human embryo growth media, including purines, pyrimidines, nitrite, and nitrate. Only some purines were detectable (hypoxanthine and uric acid) in the majority of samples, while nitrite and nitrate were always detectable. When matching biochemical results with morphological evaluation, it was found that low grade embryos (n = 12) had significantly higher levels of all the compounds of interest. Moreover, when matching biochemical results according to successful (n = 17) or unsuccessful (n = 25) pregnancy, it was found that human embryos from the latter group released higher concentrations of hypoxanthine, uric acid, nitrite, and nitrate in the culture media. Additionally, those embryos that developed into successful pregnancies were all associated with the birth of healthy newborns. These results, although carried out on a relatively low number of samples, indicate that the analysis of the aforementioned compounds in the culture media of human embryos is a potentially useful tool for the selection of embryos for implantation, possibly leading to an increase in the overall rate of ART.