In vitro evaluation of the fermentation of added‐value agroindustrial by‐products: cactus pear (Opuntia ficus‐indica L.) peel and pineapple (Ananas comosus) peel as functional ingredients

Agroindustrial by‐products derived from fruit processing are an important source of biocompounds that can be used as functional food ingredients. The objective of this work was to evaluate cactus pear and pineapple peel flours as an alternative carbon source during fermentation using bacteria with probiotic potential. The total fibre content of both flours was over 60%, with total soluble carbohydrate content around 20%, indicating a good carbon source for lactic acid bacteria. Kinetic parameters indicate that peel flours are a suitable carbon source because the lactic acid bacteria grow (mean growth rate constant, k, values close to glucose, 1.52 h) and acidify the culture media (maximum acidification rate, V_max, approximately 1.60 pH × 10^?3 min^?1). There was no difference in prebiotic potential or prebiotic activity score for both the peel flours. Pediococcus pentosaceus performs better during fermentation. In this respect, cactus pear and pineapple peel flours can be used as functional ingredients due to their fermentable properties.     

Ethanol yield and volatile compound content in fermentation of agave must by Kluyveromyces marxianus UMPe-1 comparing with Saccharomyces cerevisiae baker's yeast used in tequila production

In tequila production, fermentation is an important step. Fermentation determines the ethanol productivity and organoleptic properties of the beverage. In this study, a yeast isolated from native residual agave must was identified as Kluyveromyces marxianus UMPe-1 by 26S rRNA sequencing. This yeast was compared with the baker's yeast Saccharomyces cerevisiae Pan1. Our findings demonstrate that the UMPe-1 yeast was able to support the sugar content of agave must and glucose up to 22% (w/v) and tolerated 10% (v/v) ethanol concentration in the medium with 50% cells survival. Pilot and industrial fermentation of agave must tests showed that the K. marxianus UMPe-1 yeast produced ethanol with yields of 94% and 96% with respect to fermentable sugar content (glucose and fructose, constituting 98%). The S. cerevisiae Pan1 baker's yeast, however, which is commonly used in some tequila factories, showed 76% and 70% yield. At the industrial level, UMPe-1 yeast shows a maximum velocity of fermentable sugar consumption of 2.27g·L(-1)·h(-1) and ethanol production of 1.38g·L(-1)·h(-1), providing 58.78g ethanol·L(-1) at 72h fermentation, which corresponds to 96% yield. In addition, the major and minor volatile compounds in the tequila beverage obtained from UMPe-1 yeast were increased. Importantly, 29 volatile compounds were identified, while the beverage obtained from Pan1-yeast contained fewer compounds and in lower concentrations. The results suggest that the K. marxianus UMPe-1 is a suitable yeast for agave must fermentation, showing high ethanol productivity and increased volatile compound content comparing with a S. cerevisiae baker's yeast used in tequila production.     

Molecular rearrangements in extrusion processes for the production of amaranth-enriched,gluten-free rice pasta

Gluten-free pasta represents a challenge for food technologists and nutritionists since gluten-free materials used in conventional formulations have poor functional and nutritional properties. A novel extrusion-cooking process was set up to improve the textural characteristics of rice-based pasta, and to enrich it with amaranth. Mineral and fiber content, and protein digestibility were improved by amaranth enrichment. Extrusion-cooking of a 75/25 mixture of rice flour and amaranth prior to pasta-making gave the best results as for the textural characteristics of the final product. The firmness of cooked pasta increased due to the extrusion-cooking process, that also decreased protein solubility in the amaranth-enriched pasta. The content in accessible thiols also decreased in amaranth-enriched pastas, indicating that amaranth proteins may be involved in forming disulphide bonds during the pasta-making process. Our results suggest that starch in rice flour interacts best with amaranth proteins when starch gelatinization occurs simultaneously to protein denaturation in the extrusion-cooking process.     

Characterization of Extruded Blends of Corn and Beans (Phaseolus Vulgaris) Cultivars: Peruano and Black-Querétaro under Different Extrusion Conditions

The effect of extrusion conditions in blends of corn and beans (Phaseolus vulgaris) of cultivars Peruano and black-Querétaro were investigated in this study, as an alternative to obtain snack foods. The type of cultivar and beans percentage, and also the extrusion conditions (moisture and temperature) influenced the physicochemical (color and breaking strength) and the functional (water absorption index, water solubility index, and oil absorption capacity) properties of the extrudates. The microstructures showed the presence of cavities and starch granules gelatinized (melted) and plasticized; while, the x-ray powder diffraction patterns revealed the presence of monohydrate glucose due to starch dextrinization. The results demonstrate that extrudates with good properties can be obtained from blends of corn and beans, under selected extrusion conditions, depending on the bean cultivar.     

Effect of reagent type on the acetylation of barley and maize starches

The objective of this work was to study the effect of reagent type on properties of acetylated barley starch (BS) and maize starch (MS) after modification with acetic anhydride (AA) and vinyl acetate (VA) at similar molar concentration for mole of glucose of both reagents. Degree of substitution (DS), morphological characteristics and granule size distribution, gelatinization and retrogradation, pasting properties, and X‐ray diffraction pattern were evaluated. Acetylation disturbs the short and long range order, and the effect was higher with AA than VA, and for BS than MS. This is due to the higher DS determined in AA–BS. In the pasting profile, acetylated starch showed the maximum peak viscosity at lower temperature, this effect was strongest for BS and anhydride acetic‐acetylation. Differential scanning calorimetry showed decrease in gelatinization parameters in acetylated starches (temperatures and enthalpy), and retrogradation was suppressed by acetylation. This effect was stronger in starches acetylated with AA despite their higher DS. This pattern can be explained from the occurrence of surface effects in acetylation with AA.     

Performance impacts of autocorrelated flows in multi-tiered systems

This paper presents an analysis of the performance effects of burstiness in multi-tiered systems. We introduce a compact characterization of burstiness based on autocorrelation that can be used in capacity planning, performance prediction, and admission control. We show that if autocorrelation exists either in the arrival or the service process of any of the tiers in a multi-tiered system, then autocorrelation propagates to all tiers of the system. We also observe the surprising result that in spite of the fact that the bottleneck resource in the system is far from saturation and that the measured throughput and utilizations of other resources are also modest, user response times are very high. When autocorrelation is not considered, this underutilization of resources falsely indicates that the system can sustain higher capacities.

We examine the behavior of a small queuing system that helps us understand this counter-intuitive behavior and quantify the performance degradation that originates from autocorrelated flows. We present a case study in an experimental multi-tiered Internet server and devise a model to capture the observed behavior. Our evaluation indicates that the model is in excellent agreement with experimental results and captures the propagation of autocorrelation in the multi-tiered system and resulting performance trends. Finally, we analyze an admission control algorithm that takes autocorrelation into account and improves performance by reducing the long tail of the response time distribution.     

Periodic structures on biconically tapered optical fibers using ion beam milling and boron implantation

In this paper, the authors introduce local periodic perturbations of the cladding refractive index in the reduced diameter (waist) region of biconically tapered single-mode optical fibers by two methods. The first was focused ion beam milling to give short grooves perpendicular to the fiber axis, and the second was boron implantation, giving a phase grating in the cladding. Both structures exhibit a wavelength-dependent throughput and are highly sensitive to the environment in the waist region, which makes them potentially applicable in optical communication networks as well as in sensors. A simple corrugated slab-waveguide model is able to account for the measured spectral transmission of these structures.     

Score prognosis for the infertile couple based on historical factors and sperm analysis

OBJECTIVE: To identify variables, obtained from historical factors and sperm analysis, associated with greater chances of pregnancy in infertile couples. METHODS: The study was carried out in Córdoba, Argentina. The characteristics of 247 couples consulting for infertility who achieved pregnancy within 3 years of their first visit were compared with those of 312 couples who did not become pregnant. We evaluated the relationship between the age of the woman and her partner, the type and duration of infertility, length of the last three menstrual cycles, history of pelvic surgery in the woman, and testicular volume, sperm density, motility and morphology in her partner, and the achievement of pregnancy. For the analysis, logistic regression was used. RESULTS: Six variables had a predictive value: sperm morphology, the woman's age, type and duration of infertility, her history of pelvic surgery, and duration of menstrual cycles. CONCLUSIONS: The best prognosis for future fertility in infertile couples is correlated with a higher percentage of normal sperm morphology, younger woman's age, secondary infertility, fewer years of infertility, negative history of pelvic surgery, and abnormal menstrual cycles.     

Mental health treatment outcome by sex, diagnosis, and treatment agency.

Analyzed the effect of client characteristics and treatment on 9 dimensions of functioning (e.g., sociolegal, thought processes, and interpersonal relations) among 1,519 male and 1,877 female patients. MANOVA yielded consistent and significant differences in levels of functioning at admission as a function of sex, treatment setting, and diagnosis. Women with transient disorders showed the most adequate functioning. A Diagnosis?×?Agency interaction was also significant and indicated greater differences in functioning at admission between hospitalized and nonhospitalized Ss with "less severe" diagnoses than for Ss with schizophrenia or personality disorders. Subsequently, MANCOVA was used to partial out the effects of admission level of functioning on terminal level of functioning. Several significant differential effects of treatment and client characteristics were noted. There were fewer differences at termination than at admission, and significant differences in terminal level of functioning were observed by sex, diagnosis, and treatment agency. The interaction of sex and diagnosis was significant as was the interaction between agency and diagnosis. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)