Phenolic profiles of Andean purple corn (Zea mays L.)

Qualitative and quantitative high performance liquid chromatography with diode array detection (HPLC-DAD) was performed to characterize the presence of phenolic compounds in Andean purple corn. Phenolic compounds were analyzed by separating them in two main fractions: a water fraction (WF) and an ethyl acetate fraction (EAF). The WF rich in anthocyanins revealed the presence of cyanidin-3-glucoside, pelargonidin-3-glucoside and peonidin-3-glucoside. The respective acylated anthocyanin glucoside forms of these compounds were also detected following alkaline hydrolysis. The EAF was composed of phenolic acids such as p-coumaric, vanillic acid, protocatechuic acid, flavonoids such quercetin derivatives and a hesperitin derivative. Alkaline and acid hydrolysis of the EAF revealed the presence of p-coumaric and ferulic acid as main components in four bound hydroxycinnamic acid forms present in the ethyl acetate fraction.     

Anonymity preserving sequential pattern mining

The increasing availability of personal data of a sequential nature, such as time-stamped transaction or location data, enables increasingly sophisticated sequential pattern mining techniques. However, privacy is at risk if it is possible to reconstruct the identity of individuals from sequential data. Therefore, it is important to develop privacy-preserving techniques that support publishing of really anonymous data, without altering the analysis results significantly. In this paper we propose to apply the Privacy-by-design paradigm for designing a technological framework to counter the threats of undesirable, unlawful effects of privacy violation on sequence data, without obstructing the knowledge discovery opportunities of data mining technologies. First, we introduce a k-anonymity framework for sequence data, by defining the sequence linking attack model and its associated countermeasure, a k-anonymity notion for sequence datasets, which provides a formal protection against the attack. Second, we instantiate this framework and provide a specific method for constructing the k-anonymous version of a sequence dataset, which preserves the results of sequential pattern mining, together with several basic statistics and other analytical properties of the original data, including the clustering structure. A comprehensive experimental study on realistic datasets of process-logs, web-logs and GPS tracks is carried out, which empirically shows how, in our proposed method, the protection of privacy meets analytical utility.     

Catalytic isoforms Tpk1 and Tpk2 of Candida albicans PKA have non‐redundant roles in stress response and glycogen storage

Candida albicans cAMP‐dependent protein kinase (PKA) is coded by two catalytic subunits (TPK1 and TPK2) and one regulatory subunit (BCY1). In this organism the cAMP/PKA signalling pathway mediates basic cellular processes, such as the yeast‐to‐hyphae transition and cell cycle regulation. In the present study, we investigated the role of C. albicans PKA in response to saline, heat and oxidative stresses as well as in glycogen storage. To fine‐tune the analysis, we performed the studies on several C. albicans PKA mutants having heterozygous or homozygous deletions of TPK1 and/or TPK2 in a different BCY1 genetic background. We observed that tpk1Δ/tpk1Δ strains developed a lower tolerance to saline exposure, heat shock and oxidative stress, while wild‐type and tpk2Δ/tpk2Δ mutants were resistant to these stresses, indicating that both isoforms play different roles in the stress response pathway. We also found that regardless of the TPK background, heterozygous and homozygous BCY1 mutants were highly sensitive to heat treatment. Surprisingly, we observed that those strains devoid of one or both TPK1 alleles were defective in glycogen storage, while strains lacking Tpk2 accumulated higher levels of the polysaccharide, indicating that Tpk1 and Tpk2 have opposite roles in carbohydrate metabolism. Copyright © 2009 John Wiley & Sons, Ltd.     

Glycosylation,denaturation, and aggregation of soy proteins in defatted soy flakes flour: Influence of thermal and homogenization treatments

This article provides a systematic study of the impact of different thermal treatments (62 ± 2°C, without and with relative humidity control, 79%) on soy protein in defatted soy flour and their aqueous dispersions. The effect of dispersing treatments (magnetic stirring, high-speed, and high-pressure homogenization) on dispersions also was assessed. Changes in protein solubility (water and 0.2 g/100 g potassium hydroxide solution), apparent-reactive lysine content, urease and trypsin inhibitor activities, protein denaturation, and Fourier transform infrared spectra were studied. Glycosylation, aggregation, and denaturation of storage and biologically active soy proteins were observed in different degrees, being mainly promoted by the control of relative humidity and the dispersibility of the sample.     

Modeling water loss and oil uptake during vacuum frying of pre-treated potato slices

The objective of this research was to determine the kinetics of water loss and oil uptake during frying of pre-treated potato slices under vacuum and atmospheric pressure. Potato slices (diameter: 30 mm; width: 3 mm) were pre-treated in the following ways: (i) raw potato slices “control”; (ii) control slices were blanched in hot water at 85 °C for 3.5 min; (iii) blanched slices were dried in hot air until reaching a moisture content of ∼0.6 g water/g dry basis. The slices were fried under vacuum (5.37 kPa, absolute pressure, at 120, 130 and 140 °C) and atmospheric conditions (at 180 °C). Two models based on the Fick's law were used to describe water loss: (i) with a constant effective diffusive coefficient; and (ii) with a variable effective diffusive coefficient. Oil uptake data were fitted to an empirical model, with a linear behavior for short times whereas the model was time independent for long times. The variable diffusivity model better fitted experimental water loss, giving values of effective diffusivity between 4.73 × 10⁻⁹ and 1.80 × 10⁻⁸ m²/s. The proposed model for the study of the kinetics of oil uptake fitted the experimental data properly. Control and blanched vacuum fried potato chips increased their final oil contents to 57.1% and 75.4% respectively, when compared with those fried at atmospheric pressure. However, the oil absorption of dried vacuum fried potato chips diminished by ∼30%.     

Color of Salmon Fillets By Computer Vision and Sensory Panel

A computer vision method was developed and used to assign color score in salmon fillet according to SalmonFan™ card. The methodology was based on the transformation of RGB to L*a*b* color space. In the algorithm, RGB values assigned directly to each pixel by the camera in the salmon fillet image, were transformed to L*a*b* values, and then matched with other L*a*b* values that represent a SalmonFan score (between 20 and 34). Colors were measured by a computer vision system (CVS) and a sensorial panel (eight panelists) under the same illumination conditions in ten independent sets of experiments. Errors from transformation of RGB to L*a*b* values by the CVS were 2.7%, 1%, and 1.7%, respectively, with a general error range of 1.83%. The coefficient of correlation between the SalmonFan score assigned by computer vision and the sensory panel was 0.95. Statistical analysis using t test was performed and showed that there were no differences in the measurements of the SalmonFan score between both methods (t _c = 1.65 ≤ t = 1.96 at α = 0.05%). The methodology presented in this paper is very versatile and can potentially be used by computer-based vision systems in order to qualify salmon fillets based on color according to the SalmonFan card.     

Sacha inchi (Plukenetia volubilis L.) shell: an alternative source of phenolic compounds and antioxidants

Sacha inchi seed (SI) is known as a rich source of oil with high content of polyunsaturared fatty acids of the ω‐3 and ω‐6 type (~85% of total fatty acids). However, few studies have focused on the use of by‐products from the seed. The aim of this study was to characterise the main phenolic families present in SI shell and to evaluate the best extraction solvent for the extraction of phenolic compounds (PC) and antioxidant capacity (AOXC). The PC content corresponded to 74.5 ± 5.1 mg g^?1 of which 93.1% were condensed tannins and the remaining compounds corresponded to free and bound phenolic acids, hydrolyzable tannins, flavonoids and flavanoids. Protocatechic and p‐coumaric acids but also hydroxycinammic acid derivatives of ferulic and o‐coumaric type and lignan derivatives were identified. Acetone containing solvents favoured the extraction of higher amounts of total PC and AOXC. This study highlights the potential use of SI shell as a novel and alternative source of PC antioxidants for the nutraceutical and/or functional food industries.