- Abstract: Capillary liquid chromatography (CLC) is evaluated as an alternative to conventional HPLC to analyse complex phenolics. Several neutral phenolic compounds were separated on a packed-reversed phase fused-silica capillary column, and determined with UV detection. A conventional liquid chromatographic equipment was adapted for such purposes. Application of the proposed method to the quantification of neutral phenols in apple juices is reported. Phenolics are extracted and fractionated into... Show More
- Abstract: The capacity of alquitara (a traditional distillation system) to produce cider brandies is evaluated. To do so, the chemical composition of 12 fractions obtained during the distillation process and the cider brandies obtained from five ciders were analyzed (alcohol strength, methanol, volatile substances, furfural, and metals), taking into account European and Spanish legislation. During the course of distillation, an important increase in methanol, furfural, 2-phenylethanol, and metals in... Show More
- Abstract: A total of 350 colonies isolated from a cider cellar in Asturias (Spain) were identified by rDNA ITS-RFLP restriction analysis. Saccharomyces spp. strains were characterized by mitochondrial DNA (mtDNA) restriction analysis. Fifty-four different Saccharomyces spp. strains were identified and tested to ascertain their capacity to carry out secondary fermentation of sparkling ciders. The screening of yeasts to determine their principal enological characteristics (tolerance to ethanol,... Show More
- Abstract: The influence of cider maturation on the chemical and sensory characteristics of fresh cider spirits was evaluated in the present study. To this end, a single-factor experiment with three maturation levels and five replicates (ciders) per level was developed. Level 1 corresponded to spirits obtained when alcoholic and malolactic fermentation of the ciders ceased, Level 2 corresponded to spirits obtained from ciders with a volatile acidity of 1.0g/L acetic acid, while Level 3 corresponded to... Show More
- Abstract: In this work, a novel, simple and fast method based on solid-phase microextraction (SPME) followed by high-speed gas chromatography (HSGC) was developed for the analysis of total 1,3-octanediols in apple juices by means of derivatization reaction to volatile 1,3-dioxanes. The derivatization reaction, SPME conditions, glycosidically bound fraction and 1,3-nonanediol as a surrogate standard were studied. The formation of 1,3-dioxanes from 1,3-diols was confirmed by GC-MS. The method was... Show More
- Abstract: Headspace solid-phase microextraction coupled to Fast gas chromatography (GC) with flame ionization detector and with quadrupole mass spectrometric detector was employed to study the volatile compounds in Asturian cider apples. The best conditions used for volatile analysis of apple were: sample equilibration at 25 °C for 60 min, followed by polydimethylsiloxane-divinylbenzene fiber exposure to the headspace above the sample for 5 min, and finally thermal desorption of the adsorbed... Show More
- Abstract: A high-speed gas chromatography method has been developed to separate the fatty acids in different milk fat fractions obtained via the dry fractionation deodorization process (TIRTIAUX method). Exploratory data techniques, namely cluster analysis and principal component analysis (PCA), were applied to gas chromatographic data for fatty acids composition in these milk fractions. Cluster analysis allowed the authors to visualize natural groupings corresponding to milk fat cracking achieved via... Show More
- Abstract: The effect of different treatments involving contact with natural lees on the aromatic profile of cider has been evaluated. Comparing with the untreated ciders, the contact with lees brought about a significant increase of the concentrations of most of the volatile compounds analysed, in particular fatty acids, alcohols, ethyl esters and 3-ethoxy-1-propanol. The opposite was observed among fusel acetate esters and 4-vinylguaiacol. The addition of β-glucanase enhanced the increase of ethyl... Show More
- Abstract: A comparative study of the aroma (volatile composition and olfactometric profiles) of Asturian and Basque still ciders in two maturation stages was conducted. Among the major volatile compounds, amyl alcohols, ethyl lactate and ethyl acetate were quantitatively relevant in all of the ciders studied. The minor fraction mainly consisted of fatty acids, volatile phenols and alcohols. Three PLS-discriminat models with low prediction errors were constructed. When the volatile composition was... Show More
Publications citing this author (93)
[Show abstract] [Hide abstract] ABSTRACT: Gas chromatography combined with solid-phase microextraction has been used for the identification of the aromatic profiles of new cider apple genotypes, and a chemometric characterization of these new cider apple genotypes has been carried out using exploratory and modelling techniques. Three breeding targets have been explored: (1) regular bearing and scab resistance, (2) resistance to bio-aggressors and (3) high polyphenol content and late ripening. Exploratory techniques established two genotype groups: those that come from breeding towards targets 1 and 2 with low polyphenol contents and those that come from breeding towards target 3 with high polyphenol contents. Alcohols were related to the genotypes with breeding towards target 3, and compounds such as esters were related to the genotypes with breeding towards targets 1 and 2. Models computed using the soft independent modelling of class analogy (SIMCA) technique presented good sensitivity (93 %), specificity (91 %) and classification hits (96 %). However, the predictions computed by SIMCA (70 %) and the artificial neural network (ANN) (76 %) were low.
- A sample of 50 pieces of each apple genotype was picked from the tree at the optimal harvest time by using the starch-iodine test. This maturity index was used in agreement with Llorente et al. (2012) that established a mathematical model to predict this index from nine apple aromas. Three batches of 1–2 kg of apples per genotype were milled and pressed in a small hydraulic press (Hafico).
[Show abstract] [Hide abstract] ABSTRACT: Protein gels have attired attention since they allow structuring foods with no trans or saturated fats. The effects of protein concentration and sucrose addition on gelation kinetics and on physical properties of sodium caseinate (NaCas)/sunflower oil emulsion-based gels were studied by two methods: a new application of backscattering of light (BS) using a Turbiscan equipment and by dynamic oscillatory rheology. Structure of gels was also described by confocal laser scanning microscopy (CLSM) and small angle X-ray scattering (SAXS). T gel values decreased with increasing sucrose or NaCas concentration. BS method sensed early changes in structure, while rheological measurements were less sensitive to those changes. However, tendencies found by rheological measurements were the same as the ones found by BS experiments. CLSM images of gels formed from emulsions containing high sucrose and protein concentrations had big oil droplets that were not present in initial emulsions. Gels with sucrose concentrations between 15 and 30 wt/wt% released oil. SAXS patterns showed that NaCas nanoaggregate sizes in the aqueous phase were smaller with increasing sucrose concentration. Polar groups of protein interacted with sucrose, and therefore, interactions among protein molecules diminished. As a result of weaker protein molecule interactions, nanoaggregates were smaller. However, this effect was beneficial. In the macroscale, rheological properties and visual appearance of gels were improved. The gel formulated with 5 wt/wt% NaCas and 10 wt/wt% sucrose had a smooth surface and was stable to syneresis and oil release. This formulation was a good alternative to trans fat.
- Meanwhile, dietary guidelines in many countries continue to vilify saturated fats (Cassiday 2015). As a result of legislation and guidelines, the food industry must have alternatives to trans and saturated fats (Tarancón et al. 2013; González Álvarez et al. 2013; Blake and Marangoni 2015; Herrera et al. 2015). Protein gels have attired attention since they allow structuring foods with no trans or saturated fats.
[Show abstract] [Hide abstract] ABSTRACT: High pressure processing for producing commercially sterile low acid foods can either be treated as a pressure-assisted thermal sterilization (PATS) or a temperature-assisted pressure sterilization (TAPS) process. For a PATS process, achieving designated process lethality for commercial sterilization becomes the main issue. The selected process would rely on the effective use of compression heating of the food achieved during the pressurization process to bring the product to sterilizing temperatures and then adequately hold it under pressure to complete the sterilization process prior to releasing the pressure. In the second approach (TAPS), accelerated destruction caused by the pressure at the elevated temperatures is taken into account. Both TAPS and PATS could potentially give quality advantages to the HPP product. While the PATS process could more easily be cleared by regulatory agencies according to the guidelines used for traditional thermal processing, the TAPS process would require demonstration of accelerated spore destruction kinetics of pathogenic and spoilage bacterial spores.
- The combined odour–flavour characteristics in apple and apple products are due in part to phenol compounds. Phenols are also used as indicators of physiological state and potential damage in quality of fruit products (Blanco, Fraga, & Mangas, 2001). Phenol compounds are, thus, important biochemical substances in apple juice.
[Show abstract] [Hide abstract] ABSTRACT: Sixty six indigenous Saccharomyces cerevisiae strains were evaluated in stressful conditions (temperature, osmolarity, sulphite and ethanol tolerance) and also ability to flocculate. Eighteen strains showed tolerant characteristics to these stressful conditions, growing at 42 °C, in 0.04% sulphite, 1 mol L(-1) NaCl and 12% ethanol. No flocculent characteristics were observed. These strains were evaluated according to their fermentative performance in sugar cane juice. The conversion factors of substrates into ethanol (Y p/s), glycerol (Y g/s) and acetic acid (Y ac/s), were calculated. The highest values of Y p/s in sugar cane juice fermentation were obtained by four strains, one isolated from fruit (0.46) and the others from sugar cane (0.45, 0.44 and 0.43). These values were higher than the value obtained using traditional yeast (0.38) currently employed in the Brazilian bioethanol industry. The parameters Y g/s and Y ac/s were low for all strains. The UFLA FW221 presented the higher values for parameter related to bioethanol production. Thus, it was tested in co-culture with Lactobacillus fermentum. Besides this, a 20-L vessel for five consecutive batches of fermentation was performed. This strain was genetically stable and remained viable during all batches, producing high amounts of ethanol. The UFLA FW221 isolated from fruit was suitable to produce bioethanol in sugar cane juice. Therefore, the study of the biodiversity of yeasts from different environmental can reveal strains with desired characteristics to industrial applications.
- Flocculation was determined according to Valles et al. (2008) with some modifications. The yeast strains were inoculated in 5 mL of YPD broth and incubated at 30 °C for 72 h.
[Show abstract] [Hide abstract] ABSTRACT: A comparative study of the aroma (volatile composition and olfactometric profiles) of Asturian and Basque still ciders in two maturation stages was conducted. Among the major volatile compounds, amyl alcohols, ethyl lactate and ethyl acetate were quantitatively relevant in all of the ciders studied. The minor fraction mainly consisted of fatty acids, volatile phenols and alcohols. Three PLS-discriminat models with low prediction errors were constructed. When the volatile composition was used, ciders could be differentiated by their maturation stage, 4-ethylcatechol being strongly associated to matured ciders. The olfactometric profiles allowed the classification of ciders according to both their origin and maturation stage. Odorants such as p-cresol and a sweet-character unknown component were correlated to origin of ciders, whereas 1-octen-3-one and one unknown spicy-vegetal odorant were highly correlated to the maturation stage.
- (Beech & Carr, 1977; Sumby, Grbin, & Jiranek, 2010; Ugliano & Moio, 2005). Moreover, the influence of the contact of ciders with lees and the ability of Lactobacillus collinoides species to produce 4- ethylcatechol – among other volatile phenols-from hydroxycinnamic acids have been ascertained (Antón-Díaz et al., 2016; Buron et al., 2011b). Other components were influenced by both origin and maturation.
- The analysis of distilled spirits without initial treatment is particularly possible in case of GF-AAS. Organic matrix components, mostly ethanol, are readily evaporated at the drying and pyrolysisTable 5 Chemical modifiers used in GF-AAS analysis of spirit products Matrix modifiers with or without permanent modifiers Mg(NO3)2 with Pd(NO3)2 As [ (NH4)H2PO4 with Mg(NO3)2 Cd [20 c ,38] Mg(NO3)2 Al [34 c ] (NH4)H2PO4 Cd , Pb  Ni(NO3)2 As  Pd(NO3)2 Cr  Permanent modifiers without matrix modifiers Na2WO4·2H2O (W) Cd , Cr , Ni , Pb  (NH4)3IrCl6·H2O (Ir) Cd , Cr , Ni  RuCl3 (Ru) Cr [18,29], Ni , Sb  W-Ir Cd , Cr , Ni , Pb  W-Ru Cr , Ni  No modifier Al [17,19,24,42], Cd [17,24,42], Cu , Fe [9,53], Ni [9,29], Pb [9,14,16,17,24,31,41,42], Zn  a With a permanent Ir modifier. b With a permanent W modifier.