Water Blanching Effects on Headspace Volatiles and Sensory Attributes of Carrots

Carrots blanched in water for 0 to 300 sec were analyzed for flavor volatiles by dynamic headspace analysis, the volatiles identified by gas chromatography/mass spectrometry, and the sensory attributes evaluated by a trained panel to determine quality changes as related to blanching times. Most volatiles, in particular terpenoids (sabinene, β-pinene, β-myrcene, limonene, trans-caryophyllene, α-humulene, β-bisabolene and α-farnesene) decreased by at least 50% within 60 sec of blanching. Ratings on quality attributes of color, texture, raw carrot aroma, sweetness, flavor and overall impression decreased with blanching time, while cooked carrot aroma increased. There were correlations (p < 0.05) between blanching times, flavor volatiles and sensory attributes.     

Grade Classification of Canned Pink Salmon with Static Headspace Volatile Patterns

Pacific pink salmon (Oncorhynchus gorbuscha) were subjected to refrigerated decomposition prior to canning. Data on 44 volatile compounds obtained by static headspace gas chromatography were analyzed using multivariate statistical methods. Principal component analysis and common factor analysis showed two dimensions were particularly important to delineate variation between quality grades A, B, and reject. Three types of discriminant analysis (DA) were carried out on PCA scores as well as three selected volatiles (ethanol, 3-methyl-1-butanol, and 2-methyl-l-propanal). Although all DA procduced misclassification rates below 7%, the nonparametric Epanechnikov kemal DA was more reliable followed by quadratic and linear DA. Use of 3-methyl-1-butanol and 2-methyl-1-propanal in addition to ethanol improved the detection of initial decomposition stages.     

SENSORY AND PHYSIO‐CHEMICAL PROPERTIES OF MEMBRANE FILTERED APPLE JUICES1

Shelf‐stable apple juices were prepared using two ceramic and four polymeric tubular membranes of varying pore sizes and evaluated using color matching and triangle tests. Juices from 9 kDa and 20 kDa membranes were different in color and aroma/flavor from the other membranes, the characteristics of which did not differ from each other. A full sensory profile was obtained for experimental juices produced using a 0.02 μm ceramic membrane and from commercial pasteurized apple juice. Experimental juices were prepared from fresh and stored apples with and without ascorbic acid. Twelve judges evaluated color; cooked/caramelized, appley, fruity and green aromas and seven flavor attributes (cooked/caramelized, appley, fruity, green, sweet, sour, astringence). Analysis of variance and principal component analysis revealed that membrane filtered juices lacked the cooked/caramelized aroma and had a green flavor compared with the commercial apple juice. Membrane filtered juices prepared from freshly harvested apples had less appley and fruity aroma and flavor, but were more sour and astringent than juices prepared from stored apples. Ascorbic acid treatment significantly reduced the yellow color and increased the astringence of juices.     

Multiaxial fatigue behaviour of A356‐T6

Aluminum alloy A356‐T6 was subjected to fully reversed cyclic loading under tension, torsion and combined loading. Results indicate that endurance limits are governed by maximum principal stress. Fractography demonstrates long shear mode III propagation with multiple initiation sites under torsion. Under other loadings, fracture surfaces show unique initiation sites coincidental to defects and mode I crack propagation. Using the replica technique, it has been shown that the initiation life is negligible for fatigue lives close to 10⁶ cycles for combined loading. The natural crack growth rate has also been shown to be comparable to long cracks in similar materials.     

NONPARAMETRIC DISCRIMINANT ANALYSIS OF STATIC HEADSPACE VOLATILES FOR GRADING FRESH PACIFIC SALMON1

Whole pink salmon were iced and stored under refrigerated conditions to allow decomposition to occur. After sensory grading, static headspace volatiles were analyzed and 22 of them were retained for multivariate analysis. Principal component analysis indicated that most of the variation. (86. 5%) was carried in the first four dimensions. Six compounds received high loadings for the second principal component that was associated with quality grade variation. When used in the computation of nonparametric Epanachnikov kernel functions, ethanol and 3-methyl-1-butanol played an effective role at segregating grades A, B, and reject with a high rate of correct classification (95.6%).     

A design methodology for fractal layout organization

This paper proposes a methodology for designing job shops under the fractal layout organization that has been introduced as an alternative to the more traditional function and product organizations. We first begin with an illustration of how a fractal job shop is constituted from individual fractal cells. We then consider joint assignment of products and their processing requirements to fractal cells, the layout of workstation replicates in a fractal cell and the layout of cells with respect to each other. The main challenge in assigning flow to workstation replicates is that flow assignment is in itself a layout dependent decision problem. We confront this dilemma by proposing an iterative algorithm that updates layouts depending on flow assignments, and flow assignments based on layout. The proposed heuristic is computationally feasible as evidenced by our experience with test problems taken from the literature. We conclude by showing how the methodologies developed in this paper have helped us evaluate fractal job shop designs through specification of fractal cells, assignment of processing requirements to workstation replicates, and development of processor level layouts. This step has had the far-reaching consequence of demonstrating the viability and the validity of the fractal layout organization.     

SURFACTANT APPLICATION SYSTEM TO PREVENT ANTHOCYANIN LEAKAGE OF IQF BLUEBERRIES1

Design of an in‐line system to apply carboxymethylcellulose (CMC) surfactant to individually quick frozen blueberries to prevent anthocyanin leakage is presented. Based on design specifications a prototype system was tested. Results of anthocyanin leakage tests performed on blueberries coated using a surfactant distribution unit indicate that a small percentage by weight (such as 1%) of surfactant is effective in reducing anthocyanin leakage. Economic evaluation of the system design revealed a cost range for blueberries from $0.04 to $0.09 per kg. Price of the CMC surfactant had the greatest effect on total operational cost of the system. The designed system represents the best overall system for applying surfactant to blueberries without slowing existing processing operations. Overall, the surfactant application system is not a great economic burden for processors, if customers are willing to absorb the slightly higher cost per kg of coated blueberries.