Comparison of physicochemical pretreatments of banana peels for bioethanol production

Pretreatments with different concentrations of sulfuric acid (0, 0.5, and 1% v/v) and temperatures (28 and 121 °C at 103 kPa in an autoclave) were performed on banana peels (BP) milled by mechanical grinding and grinding in a blender as well as without grinding. Cellulose, hemicellulose, lignin, ash, and total and reducing sugar contents were evaluated. The highest yields of cellulose enzymatic hydrolysis (99%) were achieved with liquefied autoclaved BP treated with 0.5 and 1% acid after 48 h of hydrolysis. Ethanol production by Kluyveromyces marxianus fermentation was assayed using hydrolyzed BP at 10, 15, and 20% (w/w). The highest ethanol level (21 g/L) was reached after 24 h of fermentation with 20% (w/w) BP. Kinetics of the consumption of reducing sugars under this fermentation condition demonstrates the presence of a lag period (about 8 h). Thus, BP are a good source for ethanol production.     

Ling Heather Honey Authentication by Thixotropic Parameters

This paper assesses the actual reliability of four rheological parameters to help describe honeys that exhibit non-Newtonian behavior, being the most representative of which, ling heather (Calluna vulgaris (L.) Hull) honeys. Sampling included a representative number of unifloral ling heather honeys, non-unifloral honeys close to ling heather uniflorality, and other non-unifloral honeys containing ling heather. All experiments were performed at 25 °C and consisted on researching viscosity curves at different shear rates, as well as the time dependency of honey samples at a constant shear rate. Viscosity curves were correctly fitted by the Ostwald-de Waele model. Consistency coefficients (k) and flow behavior indexes (n) were calculated, and the Weltmann model was used to determine the stress decay behavior. The influence of honey moisture on k value was also researched. Hysteresis area and time-dependent thixotropic index B proved to be the most suitable parameters for a reliable ling heather honey authentication.     

Foodborne Salmonella-caused outbreaks in Catalonia (Spain), 1990 to 2003

In most developed countries, nontyphoid Salmonella is an important cause of sporadic cases and outbreaks of foodborne gastroenteritis. The aim of this study was to investigate the trend of foodborne Salmonella-caused outbreaks and number of cases, hospitalizations, and deaths and compare them with those caused by other infectious agents. The study was carried out in Catalonia, a region in northeastern Spain with a population of 6.5 million inhabitants, in 2002. All information on reported outbreaks of foodborne disease from 1990 to 2003 was reviewed. For each outbreak, the following variables were collected: year; setting (household, restaurant, school, hospital, nursing home, and others); number of cases, hospitalizations, and deaths; causal agent; and food vehicle involved. Of 1652 reported outbreaks, 1078 had a known causal agent. Among them, 871 (80.8%) were caused by Salmonella, with 14,695 cases, 1534 hospitalizations, and 4 deaths. The rate of hospitalization was higher in outbreaks due to Salmonella than in those caused by other infectious agents (rate ratio, 2.54; 95% confidence interval, 2.20 to 2.94). Forty-eight percent of Salmonella-caused outbreaks were eggborne, compared with 5.3% of those caused by other infectious agents (rate ratio, 1.40; 95% confidence interval, 1.33 to 1.48). The annual number of cases in household outbreaks of eggborne Salmonella rose over time (R2 = 0.82), but the number of outbreaks produced in other settings did not. Eggborne outbreaks caused by Salmonella in households are a major cause of disease, and increased preventive efforts are necessary, especially consumer education and awareness of the risk of eating food containing raw or slightly cooked eggs.     

Influence of sensory characteristics on the acceptability of dry-cured ham

The influence of different sensory attributes on the acceptability of dry-cured Iberian ham was studied. Partial least squares regression analysis showed that juiciness and several flavour traits were the major attributes positively influencing acceptability of dry-cured Iberian ham, whereas yellowness of the fat, dryness and fibrousness showed a negative influence. Using stepwise multivariate regression, juiciness and flavour intensity were the two traits that better explained the acceptability of dry-cured ham, the linear model obtained showing a regression coefficient of 0.526. The regression coefficient of acceptability with juiciness and flavour intensity was higher using a piecewise linear regression model (R²=0.759) showing, therefore, a discontinuous relationship between these variables. However, results on product acceptability have been obtained using trained panellists and it might be possible that the use of a consumer panel would change these conclusions.     

Statistical analysis of the quantal basis of secretory granule formation

ABSTRACT The size distribution of vesicles exocytosed from secretory cells displays quantal nature, vesicle volume is periodic multi‐modal, suggesting that these heterogeneous vesicles are aggregate sums of a variable number of homogeneous basic granules. Whether heterogeneity is a lumping‐together artifact of the measurement or an inherent intra‐cell feature of the vesicles is an unresolved question. Recent empirical evidence will be provided for the quantal nature of intra‐cell vesicle volume, supporting the controversial paradigm of homotypic fusion: basic cytoplasmic granules fuse with each other to create heterogeneously sized vesicles. An EM‐algorithm‐based method is presented for the conversion of multi‐modal to quantal data that provides as by‐product estimates of means and variances of basic granule packaging. Microsc. Res. Tech. 77:1–10, 2014. © 2013 Wiley Periodicals, Inc.     

Carcass classification in suckling lambs. II. Comparison among subjective carcass classification methods: fatness scales and conformation scales with 0.25 point-intervals

Forty-nine Manchega breed suckling lambs were used. Carcass weight was less than 13 kg, and lambs were slaughtered at 10, 12 and 14 kg liveweight. Carcasses were classified by three assessors on colour photographs, by several classification methods: the European Union scale for light lambs carcasses (EU), Colomer-Rocher methods for fatness (CF) and conformation (CC), and the new scale for suckling lambs (SL) developed by our research group. Carcasses were also assessed using these scales divided into 0.25 point-intervals (EU-25, CF-25, CC-25 and SL-25). A correlation analysis was made between assessors score and tissue composition in the carcass and in three joints (leg, best end of neck and loin, and shoulder). For all the methods studied 0.25 point scales were best correlated to tissue composition than 1.0 points-interval scales. When 1.0 point-interval scales were used the SL scale was best correlated to tissue composition. When 0.25 point-scales were used, the EU scale gave the best correlations. Conformation scale (CC) was useful to predict carcass composition, specially kidney knob and channel fat content.     

Bakery products enriched with phytosterols, α-tocopherol and β-carotene. Sensory evaluation and chemical comparison with market products

A sensory evaluation of croissants and magdalenas (Spanish muffins) has been carried out to compare them with the same products with phytosterol esters, α-tocopherol and β-carotene added. The subjects were habitual consumers and no differences were detected between the two types of product. Furthermore, the chemical composition (53 parameters) of croissants (n = 9) and muffins (n = 8) marketed in Spain, has been analysed and a nutritional evaluation performed on these products with regard to their suitability as carriers of the functional ingredients mentioned above. The chemical compositions are not similar and the main difference is related to fatty acids. Croissants are characterized by a high percentage of saturated fatty acids (SFA) (44.0 ± 3.8%), and the presence of trans fatty acids (TFA) (4.29 ± 1.48%). This contrasted with the high content of polyunsaturated fatty acids (PUFA) (62.1 ± 1.5%) in the muffins and the near absence of TFA (0.16 ± 0.23%). Furthermore, the large differences between the compositions of the commercial croissants and muffins (magdalenas) and, therefore, between their nutritional values, makes the use of phytosterols recommendable in muffins and, in general, in all bakery products in which the SFA + TFA represent ?20% of the fatty acid fraction.     

ASME Section Ⅲ Stress Analysis of a Heat Exchanger Tubesheet with a Misdrilled Hole and Irregular or Thin Ligaments

A stress analysis is described for a nuclear steam generator tubesheet with a thin, or irregular ligament, associated with a mis-drilled hole using the rules of ASME （American Society of Mechanical Engineers） B ＆ PV Section Ⅲ and non-mandatory Appendix A, Article A-8000 for stresses in perforated flat plates. The analysis demonstrates the proper application of the NB-3200 rules for this special application, with discussion of the differences between an actual tube hole deviation and what is assumed in ASME Appendix A. This is a companion paper to ＂Technical Justification Supporting Operation with a Tube Installed in a Mis-Drilled Hole of a Steam Generator Tubesheet＂.