Crystal Control In Processed Liquid Honey

Liquid processed honeys produced in the province of Alberta, Canada, were studied to identify controllable factors to delay glucose crystallization. Individual producer honeys were analyzed for glucose and fructose using a new HPLC procedure. Selective use of producer honeys for liquid processed honey was of no advantage since the samples were all supersaturated in glucose (>30% glucose) and contained unexpectedly consistent fructose/glucose ratios of about 1.12. Crystallization could be delayed by filling retail containers at 45 °C or above. Moisture losses noted at well over 1% a year in plastic containers could also contribute to an increase in crystallization for stored honey.     

FRUSTRATIVE NONREWARD THEORY APPLIED TO CHILDREN'S BEHAVIOR.

REVIEWS RESEARCH RELATING TO CHILDREN'S REACTIONS TO NONREWARD IN A VARIETY OF EXPERIMENTAL SITUATIONS. PERFORMANCE IN NONCONTINUOUS RATHER THAN CONTINUOUS REWARD SITUATIONS WAS FOUND TO BE MORE VIGOROUS. THESE DATA AND THE RESULTS OF STUDIES DEALING WITH DISCRIMINATION LEARNING AND DIFFERENTIAL CONDITIONING PROVIDE CROSS-SPECIES SUPPORT FOR AMSEL'S FRUSTRATIVE NONREWARD THEORY. THE EFFECTS OF NONREWARD ARE ALSO EXAMINED IN RELATION TO CA, MA, PERSONALITY, SOCIAL FACTORS, AND SUCCESS-FAILURE MANIPULATIONS. FRUSTRATIVE NONREWARD THEORY MAY BE POTENTIALLY USEFUL IN DERIVING RELATED HYPOTHESES. (2 P. REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CONTROL OF DEFORMATION IN TEXTURE TESTS *

Abstract. The motion of the Instron crosshead during small deformations (e. g. 0.25 mm) in tensile tests performed at the available range of deformation rates was examined. Large errors are introduced in the deformation readings if it is assumed that the deformation rate was constant at the rate selected because, as with any instrument of this type, the crosshead requires time to accelerate to the selected speed. The characteristic behaviour of the food is subject to misinterpretation if the applied deformation profile is unknown. It was found that the errors are larger when the instrument is used incorrectly by performing tensile tests below the crosshead. The work demonstrated some of the limitations that must be recognized when applying the Instron, or any deformation mechanism, to certain texture tests. It is concluded that food behaviour, under small deformations, could be recorded precisely and interpreted correctly providing that both the force and deformation are recorded against time. Control of the crosshead stopping and reversal points was also examined, particularly in relation to the instrumental texture profile analysis. Crosshead acceleration affects the readings and interpretation of the data at the reversal point. If the deformation rate is changed, the stopping point must be adjusted.     

Fermentation properties of a wine yeast over-expressing the Saccharomyces cerevisiae glycerol 3-phosphate dehydrogenase gene (GPD2)

Wine yeasts efficiently convert sugar into ethanol. The possibility of diverting some of the sugar into compounds other than ethanol by using molecular genetic methods was tested. Over-expression of the yeast glycerol 3-phosphate dehydrogenase gene ( GPD2 ) in a laboratory strain of Saccharomyces cerevisiae led to an approximate two-fold increase in the extracellular glycerol concentration. In the medium fermented with the modified strain, acetic acid concentration also increased approximately two-fold when respiration was blocked. A strain deleted for the GPD2 gene had the opposite phenotype, producing lower amounts of glycerol and acetic acid, with the latter compound only reduced during non-respiratory growth. A commercial wine yeast over-expressing GPD2 produced 16.5 g/L glycerol in a wine fermentation, compared to 7.9 g/L obtained with the parent strain. As seen for the laboratory strain, acetic acid concentrations were also increased when using the genetically modified wine yeast. A panel of wine judges confirmed the increase in volatile acidity of these wines. The altered glycerol biosynthetic pathway sequestered carbon from glycolysis and reduced the production of ethanol by 6 g/L.     

Management practices for Sunmuscat (Vitis vinifera L.): a new drying variety

Sunmuscat grapevines, managed on one of three trellis × two row spacing configurations, and grown on either their own roots or grafted onto Ramsey rootstock, were assessed over nine seasons (1990–1998 inclusive). The three trellis systems comprised (1) a 0.3 m narrow T‐trellis (NT), (2) a 1.2 m wide T‐trellis (WT), both with a 3.3m row spacing and a height of 1.2 m, and (3) a high (1.8 m) hanging cane (HC) system based on bi‐lateral cordons with a 2.2 m row spacing. Vine spacing within rows was 2.4 m irrespective of row width. A trellis drying treatment was compared with hand harvest during 1991–1995. Over the nine seasons, individual WT vines sustained highest yields of fresh grapes (23.7 kg/vine.season) compared to either NT (20.9 kg/vine) or HC vines (20.8 kg/vine) respectively (P < 0.001). However, HC vines expressed a considerable production advantage on a per hectare basis, viz. 41.3 t/ha, due to closer row spacing. Corresponding vineyard productivity for NT and WT vines was 26.4 and 29.9 t/ha respectively. Both WT and HC vines showed significantly higher bunch and shoot numbers than the NT treatment (P < 0.05 and P < 0.001, respectively). Nevertheless, trellis treatment had no effect on fruitfulness, berry weight, bunch weight, total soluble solids or titratable acidity. Taken overall, vines grafted to Ramsey rootstock had higher mean yields than vines on their own roots (i.e. 23.6 and 20.1 kg /vine, respectively P < 0.001) due to more berries per bunch and larger berries, despite having significantly fewer shoots and bunches. There was no long term evidence for incompatibility of Sunmuscat grafted to Ramsey rootstock. Compared to hand harvest of fresh grapes, trellis drying had no effect on yield, shoot and bunch numbers. Development of significantly smaller berries with trellis drying was offset by higher levels of total soluble solids. Sunmuscat is clearly a highly productive variety and is suited to canopy management on tall, cordon‐based hanging cane systems which are also amenable to trellis drying.