Use of Mechanically Separated Spleen in Frankfurters

Beef and pork frankfurters were produced with 0, 5, 10, and 15% of the meat block being mechanically separated spleen (MSS). No fatting or peelability problems were experienced. Frankfurters were held at 2°C and evaluated at 2-wk intervals for 6 wk. Consumer panelists rated all products acceptable. A bi-monthly laboratory taste panel evaluated all frank furters (except the 15% product) acceptable during storage. Allo-Kramer shear values decreased with increased MSS, Frankfurters with 5, 10, and 15% MSS had 2.2, 3.9, and 4.9 times more iron than the control, respectively. Level of MSS did not influence bacterial numbers.     

DEVELOPMENT OF PASTEURIZATION PROCESS FOR ROCK CRAB MEAT (CANCER IRRORATUS)

Rock crab (Cancer irroratus) is abundant in the southern Gulf of St. Lawrence and along coastlines of the Atlantic region of Canada. The objective of this work was to prepare a pasteurization schedule for Atlantic Canadian Rock Crab meat (claw, leg and body). Samples of 175 g of meat plus 52 g of 2% w/w brine or 125 g meat plus 102 g brine were placed in an 8 oz polypropylene container with an aluminum pull-top lid. The slowest heating spot for a conductively heating product was found to be 3.0 cm below the lid. Pasteurization was evaluated at 81C, 82C and 83C to a pasteurization lethality of 40 min at 85C (z = 8.89 C). The heat penetration parameters obtained were j_h= 1.703, f_h= 34.8 min, j_c= 1.549 and f_c= 51.0 min. The optimal process was found to be 83C for 130 min. The shear strength for unprocessed crab leg samples was, on average, 0.33 N/mm² (±0.06) compared to 0.24 N/mm² (+0.02) for processed samples. This represents 27.4% reduction in the shear stress that is largely attributed to the processing method. Thirty two free amino acids were determined including 9 essential amino acids, and their total amounts ranged between 24.8% and 30.0% of the sample, on dry basis. The total amounts of essential amino acids in the processed and unprocessed samples were, respectively, 15.3 and 17.8 mg/g sample. No significant losses in the amounts of essential amino acids was observed between processed and unprocessed samples, except for methionine, isoleucine and lysine, which were significantly reduced in the processed samples.     

Yeast viability during fermentation and sur lie ageing of a defined medium and subsequent growth of Oenococcus oeni

Interactions between the yeast strain used for primary oenological fermentation and the bacterium used to conduct subsequent malolactic fermentation were studied under model winemaking conditions. A commercial Saccharomyces cerevisiae wine yeast (strains, EC 1118, AWRI 835 and CY-3079) was grown in a defined medium whose composition approximated grape juice. Fermentations by all strains reached dryness, and retained a cell viability of greater than 90% upon completion of fermentation. Highest total viable cell number and percentage of viable cells were recorded for EC 1118. A sur lie ageing of the fermented medium over a 12 week period revealed a bi-phasic decay of culture viability for all strains. Thus 99% of cells had died within 2 weeks post-fermentation. Viabilities were then stable for the subsequent 4–6 week period before a second decline phase ensued and ended in either a minimal ( ca 100 CFU/mL, EC 1118) or no viable cells being detected at 12 weeks of ageing. The growth response of an Oenococcus oeni inoculum to yeast culture supernatants, previously aged for up to 12 weeks in the presence or absence of yeast lees, was evaluated in a bio-assay. In this way, yeast strains could be designated as being either inhibitory, neutral or stimulatory to the growth of O. oeni (strain Lc5p). Inhibition by supernatants of strain EC 1118 was evident, but found to be reduced by ageing the supernatant (with or without lees). Conversely, longer ageing on yeast lees increased the magnitude of the stimulatory response in O. oeni (strain Lc5p) to the supernatant from the wine yeast (strain CY-3079).     

Immobilized α-amylase from Bacillus licheniformis: a potential enzymic time—temperature integrator for thermal processing

Biphasic and nth-order models were tested as to their usefulness to fit experimental inactivation data of Bacillus licheniformis α-amylase, immobilized on glass beads, and were discussed with respect to their suitability to characterize the considered enzymic system as a time—temperature integrator (TTI) to evaluate heat processes. Both isothermal and non-isothermal inactivation experiments were carried out. Model (kinetic) parameters (rate constant k, activation energy E_A and reaction order n) were estimated using a non-linear regression procedure. The results obtained, especially the activation energy of about 293 kJ mole^–1, indicated a potential use of this system as a TTI for heating processes in the temperature range of 96–108°C.     

A SURVEY OF THE PREVALENCE OF SALMONELLA AND OTHER ENTERIC PATHOGENS IN A COMMERCIAL POULTRY FEED MILL

A study of the prevalences of Salmonella, Listeria and thermophilic campylobacters in a dedicated commercial poultry feed mill was undertaken. Salmonella was frequently recovered in samples taken in the preheat and postheat treatment areas of the mill with the overall percentage of samples positive found to be 18.8% and 22.6%, respectively. Feed ingredients and dust collected in the preheat treatment locations within the mill were frequently contaminated with Salmonella (11.8% and 33.3% of samples, respectively). High prevalences of Salmonella were also detected in dust samples (24.2%) obtained from the postheat treatment area of the mill and from feed delivery vehicles (57.1%).
Listeria was also recovered from samples at pre- and postheat treatment areas within the mill with overall isolation rates of 14.1% and 18.5% observed, respectively. The most frequently observed species of Listeria recovered from samples in both areas within the mill was L. innocua, L. monocytogenes, L. grayi and L. welshimeri.
No thermophilic campylobacters were recovered from any of the samples analyzed in the current study.     

Factors Affecting 1-Octen-3-ol in Mushrooms at Harvest and During Postharvest Storage

Harvesting experiments revealed that immature whole mushrooms with closed veils had higher 1-octen-3-0l levels than more mature whole mushrooms with open veils. The l-octen-3-01 content of the gills was higher in immature mushrooms with closed veils, gradually decreased with maturity as the veil opened, and finally increased after the gills were well exposed. Postharvest experiments demonstrated that storage temperature influenced the activity of lipoxygenase-hydroperoxide lyase, but no differences in 1-octen-3-01 content were observed. Enzyme activity as well as 1-octen-3-01 content decreased during storage. Addition of calcium chloride to irrigation water, employed to improve quality and shelf life of fresh mushrooms, increased the amount of l-octen-3-01 immediately after harvest.     

Flavor and Stability of "Horchata De Chufas"

Horchata is a sweetened water extract of chufa tubers (Cyperus esculentus) which is very popular in Spain, and has potential in the U.S. The objectives of this research were to characterize horchatas from different types of chufa, and to monitor flavor and stability of unheated and pasteurized horchatas during storage (2°C). Trained panelists rated the following attributes: color, chalkiness, sweetness, vanilla-like, nutty, earthiness, bitterness, and off-flavor. Horchatas made with chufa grown in Spain and chufa from Spain but grown in Florida showed higher vanilla and nutty levels than horchata from the Florida type. During storage (2°C), vanilla, nutty, and sweetness decreased, and other attributes increased. Heating to 70 and 95°C for 1 min did not alter sensory attributes initially, prevented off-flavor development, and slowed changes in desirable attributes for 35 days.     

Structural Aspects of the Lattice Thermal Expansion of Hexagonal Cordierite

The mechanism of lattice thermal expansion in pure hexagonal cordierite prepared by glass devitrification was investigated by time-of-flight neutron powder diffraction at temperatures from 22° to 750°C under vacuum. Full matrix least-squares refinement of the diffraction spectra was carried out in space group P6/mcc using the Rietveld method. The structural data from the refinements were resolved into components parallel and normal to the c axis. The negative c axis expansion results from two effects: (1) increasing distortion of the T₂ tetrahedral (ring tetrahedra) with temperature, primarily due to displacement of the T₂ cations toward the c-axis channels in the structure; (2) decreasing distortion of the T₁/M tetrahedra/ octahedra with increasing temperature, due to octahedral I (M-O₁) bond expansion and an associated decrease in torsional distortion of the T₁ tetrahedra.