Some natural properties of strong-identification in inductive inference

In this paper the problem of inducing an algorithm for a partial recursive function from the analysis of its graph or loosely speaking of “learning” it, is discussed.A certain number of results are obtained mainly relatively to the question of whether, given a machine M able to learn all functions within a set C, one can construct a machine M' able to learn a new set C' related in some “natural” way to C, by using the experience of M.     

The effect of grape seed extract or Cistus ladanifer L. on muscle volatile compounds of lambs fed dehydrated lucerne supplemented with oil

Thirty-six Merino Branco lambs were assigned to six dietary treatments: control diet (C) consisting of 90% dehydrated lucerne and 10% wheat bran; control diet with 6% of oil blend (CO); control with 2.5% of grape seed extract (GS); control with 2.5% of grape seed extract and 6% of oil blend (GSO); control with 25% of Cistus ladanifer (an aromatic bush widespread in Portugal; CL); control with 25% of C. ladanifer and 6% of oil blend (CLO). The muscle longissimus dorsi was then subjected to the analysis of volatile compounds (SPME–GC/MS). The CLO diet increased the concentration of heptanal, 3-hydroxy-2-butanone and 2-ethyl-phenol in muscle compared to the CL diet. When lambs received the CL diet, their meat contained lower amounts of 4-heptenal compared to the other treatments. The meat of the GS and GSO lambs contained similar amounts of volatile compounds deriving from lipid oxidation (such as heptanal, 2-nonenal, 4-heptenal and 3-hydroxy-2-butanone). These results indicate that in the presence of grape seed extract, oil supplementation did not enhance the production of lipid-derived volatile compounds. Verbenone and 2,2,6-trimethyl-cyclohexanone were detected only in the meat of the Cistus-fed lambs, suggesting that these compounds could be markers of feeding Cistus-containing diets. Meat volatile compounds profile allowed to discriminate between the lambs receiving C. ladanifer and those not receiving this bush in the diet.     

Optimization of Matrix Solid-Phase Dispersion Method for Extraction of Aflatoxins from Cornmeal

An extraction method for simultaneous determination of aflatoxins (AFLAs) G2, G1, B2, and B1 in cornmeal, based on vortex-assisted matrix solid-phase dispersion (MSPD) and high-performance liquid chromatography (HPLC) with fluorescence detection was optimized by a central composite design, validated and applied. Multivariate analysis was performed to evaluate the effect of cornmeal composition on AFLA extraction. The amount and proportion of solid support (celite and C18) and volume of elution solvent (methanol and acetonitrile) were the variables tested. The mobile phase of methanol/acetonitrile/water (24:14:62, v/v/v) in isocratic elution mode provided satisfactory AFLA separation. The best recoveries (85.7 to 114.8%) were obtained when the sample preparation contained 25 mg C18 as solid support and 10 mL of elution solvent. The limits of detection ranged from 0.01 to 0.04 ng g^?1, and the limits of quantification varied from 0.02 to 0.1 ng g^?1. The optimized method was suitable for coarse and medium grind cornmeal. Multivariate correlation analysis showed that the main interferers for AFLA recovery were proteins and sugars.     

Survival of Lactobacillus delbrueckii UFV H2b20 in ice cream produced with different fat levels and after submission to stress acid and bile salts

The survival of Lactobacillus delbrueckii UFV H2b20 in three ice cream formulations (low fat, fat free and high fat) was evaluated after the processing and storage at ?16 °C. The survival of L. delbrueckii UFV H2b20 was not significantly affected (P > 0.05) in three ice cream formulations after processing. The same result was observed during storage for 40 days at ?16 °C. Cells of L. delbrueckii UFV H2b20 incorporated in three ice cream formulation survived when exposed to acid stress and bile salts. The results demonstrate that L. delbrueckii UFV H2b20 has potential for being used in ice cream and capacity to resist acid stress and to grow in the presence of bile salts. This demonstrates that reduction of fat in ice cream does not compromise the viability of L. delbrueckii UFV H2B20.     

Response surface analysis of extract yield and flavour intensity of Brazilian cherry (Eugenia uniflora L.) obtained by supercritical carbon dioxide extraction

This work evaluated the effect of pressure and temperature on yield and characteristic flavour intensity of Brazilian cherry (Eugenia uniflora L.) extracts obtained by supercritical CO₂ using response surface analysis, which is a simple and efficient method for first inquiries. A complete central composite 2² factorial experimental design was applied using temperature (ranging from 40 to 60 °C) and pressure (from 150 to 250 bar) as independent variables. A second order model proved to be predictive (p ≤ 0.05) for the extract yield as affected by pressure and temperature, with better results being achieved at the central point (200 bar and 50 °C). For the flavour intensity, a first order model proved to be predictive (p ≤ 0.05) showing the influence of temperature. Greater characteristic flavour intensity in extracts was obtained for relatively high temperature (> 50 °C). Therefore, as far as Brazilian cherry is concerned, optimum conditions for achieving higher extract yield do not necessarily coincide to those for obtaining richer flavour intensity.Industrial relevanceSupercritical fluid extraction (SFE) is an emerging clean technology through which one may obtain extracts free from organic solvents. Extract yields from natural products for applications in food, pharmaceutical and cosmetic industries have been widely disseminated in the literature. Accordingly, two lines of research have industrial relevance, namely, (i) operational optimization studies for high SFE yields and (ii) investigation on important properties extracts are expected to present (so as to define their prospective industrial application). Specifically, this work studied the optimization of SFE process to obtain extracts from a tropical fruit showing high intensity of its characteristic flavour, aiming at promoting its application in natural aroma enrichment of processed foods.     

Characterization and determination of brewer's solid wastes composition

Agro‐industrial wastes are produced in large quantities around the world from the processing and manufacturing of food and beverages. The disposal of these wastes into the environment leads to damage to ecosystems owing to their composition rich in organic matter. In this context it may be noted that the brewing industry, whose production process includes processing steps and fermentation of vegetable raw materials such as barley and/or other grains used as adjuncts and hops, generates various byproducts. The worldwide consumption of these beverages and the current model of breweries, which includes production on a large scale, lead to the generation of large amounts of brewery waste, namely spent grain, hot trub and residual yeast. Owing to its composition, these residues exhibit significant potential for application in bioprocess technologies. In this study the three residues mentioned had their composition determined as a function of moisture, ash, total organic carbon (TOC), total and soluble nitrogen, reducing sugar and soluble free amino nitrogen. Moreover, the residues were characterized for total acidity, pH and chemical oxygen demand (COD) of total and soluble fractions. The three residues evaluated had high moisture content (>80%) and high organic matter content (TOC and COD, ~50% and >1000 mg/g, respectively), which can highlights the significant protein fraction (almost 50% for hot trub and residual yeast), suggesting the possibility of using these wastes for recovery. Copyright © 2015 The Institute of Brewing & Distilling     

Mycotoxins in Bovine Milk and Dairy Products: A Review

This paper presents a literature review of the occurrence of several mycotoxins in bovine milk and dairy products, because it is the main type of milk produced and marketed worldwide. Mycotoxins are produced by different genera of filamentous fungi and present serious health hazards such as carcinogenicity and mutagenicity. Under favorable growth conditions, toxigenic fungi produce mycotoxins which contaminate the lactating cow's feedstuff. During metabolism, these mycotoxins undergo biotransformation and are secreted in milk. Data show that there is a seasonal trend in the levels of mycotoxins in milk, with these being higher in the cold months probably due to the prolonged storage required for the cattle feeds providing favorable conditions for fungal growth. Good agricultural and storage practices are therefore of fundamental importance in the control of toxigenic species and mycotoxins. Although aflatoxins (especially aflatoxin M₁) are the mycotoxins of greater incidence in milk and dairy products, this review shows that other mycotoxins, such as fumonisin, ochratoxin A, trichothecenes, zearalenone, T‐2 toxin, and deoxynivalenol, can also be found in these products. Given that milk is widely consumed and is a source of nutrients, especially in childhood, a thorough investigation of the occurrence of mycotoxins as well the adoption of measures to minimize their contamination of milk is essential.     

Codex dietary fibre definition – Justification for inclusion of carbohydrates from 3 to 9 degrees of polymerisation

The main controversy about the DF definition, adopted by the commission of Codex Alimentarius, refers to the inclusion of carbohydrates of 3–9 degrees of polymerisation (DP), decision which may be made individually by the authorities of each country. Due to the possibility of having two definitions and the negative impact it would cause over the harmonisation of nutritional information, a bibliographic review was carried, from 2009 to 2011, aiming to gather justifications for the inclusion of carbohydrates of 3–9 DP in the definition. The current review presents scientific bases that are directed to three topics: physiological aspects; repercussion over the analytical method; and impact on consumers and other users. The decision of including unavailable carbohydrates of 3–9 DP in the definition of DF may cause effective global harmonisation in the nutritional labelling, considering that the main goal is to help consumers choose healthy foods.     

Influence of the isolation procedure on the characteristics of fiber-rich products obtained from quince wastes

The upgrading potential of quince (Cydonia oblonga Miller) wastes was evaluated for production of fiber-rich powders with useful functional and physiological properties. As a first approach, three products were obtained by applying different drying conditions without or with a previous extraction either with water or ethanol. Chemical compositions as well as physical and functional properties of the isolated fractions were evaluated in relation to water or oil absorption for characterization. The products obtained presented interesting hydration properties comparable to those reported for citrus and apple pulps. At the same time, all dried fractions showed high spontaneous water absorption rate in the kinetics assay. Oil absorption seemed to essentially depend on the microstructural characteristics of the fiber powders, whereas parameters involving water absorption were really determined by the material’s hydrophilicity. Specific volume, which was also in part a direct function of structural differences, was associated to the ability for oil uptake.