Wine bottle closures: physical characteristics and effect on composition and sensory properties of a Semillon wine 1. Performance up to 20 months post-bottling

A Semillon wine was bottled using 14 different closures: a screw‐cap type, two grades of conventional natural cork, two ‘technical cork’ closures (natural cork with a synthetic component), and 9 closures manufactured from synthetic polymer material. Closure performance was evaluated for physical aspects (e.g. extraction force and energy, change in closure diameter, and ease of closure reinsertion), and for wine composition and sensory properties. Wine under the screw cap closure retained the greatest concentration of sulfur dioxide (SO₂) and ascorbic acid and had the slowest rate of browning. For other closures the trend of SO₂ loss relative to the screw cap closure was apparent from an early stage of testing, and was most evident in the group of synthetic closures, intermediate in the conventional corks, and least evident in the technical cork closures. The loss of SO₂ was in general highly correlated with an increase in wine browning (OD₄₂₀) and the concentration of SO₂ in the wine at six months was a strong predictor of future browning in the wine, particularly after eighteen months. Neither the concentration of dissolved oxygen at bottling (0.6–3.1 mg/L), nor the physical closure measures were predictors of future browning. For several closures upright storage tended to accelerate loss of SO₂ from the wine, but in many cases this effect was marginal. The closures differed widely in regard to physical characteristics, and in general synthetic corks appeared least ‘consumer‐friendly’ in terms of extraction forces, energies, and ease of closure re‐insertion, but there was a trend for natural cork closures to exhibit larger variability in physical characteristics than technical cork and synthetic closures. Sensory analysis indicated large differences in wine flavour properties, with closures which tended to result in the best retention of free SO₂ having wine sensory scores for ‘citrus’ that were generally high whilst scores for the attributes ‘developed’/‘oxidised’ were low. The situation was reversed for wine under closures that performed poorly in the retention of free SO₂. It was found that below a critical level of free SO₂ remaining in the wine, closures exhibited substantially higher ‘oxidised’ aroma. Whilst trichloroanisole‐type (TCA) taint was a noticeable problem for some cork and technical cork closures, any plastic‐type taint appeared not to be a problem with most synthetic closures.     

Influence of trypsin action in yoghurt milk on the release of caseinophosphopeptide-rich fractions and physical properties of the fermented products

The influence of trypsin action in yoghurt milk on the release of caseinophosphopeptide (CPP)-rich fractions was studied and the physical properties of the fermented products determined. Trypsin treatment of skim milk led to increased fermentation times and a substantially lowered production of l -lactic acid as well as to delayed and reduced proteolysis caused by peptidases of the starter cultures. The functional properties of the milk proteins were decreased and the sensory properties less pronounced in yoghurt from trypsin-treated milk, but were described as less bitter than samples from nontreated milk. The CPP sequences β-CN(1–25)-4P and α _s1 -CN(43–79)-7P were released during enzyme treatment.     

绪森集聚纺纱理论

正集聚的目的是使纤维在即将加捻之前彼此既平行又非常接近地排列,这种设置纤维的方式将使集聚纺纱具有其特有的性能,纺纱三角区的消除仅仅是这种设置的一个结果。以下尝试解释在集聚区发生的实际情况。所有成功的集聚纺纱系统都具有以下特点:a)在正常的三罗拉牵伸系统的出口与钳口线之间有一个集聚区;b)这个区域由一个带集聚槽的吸风管组成,集聚槽倾斜于纱线路径的方向,集聚槽内施加了负压;c)一个带网眼器材的输送方法(如网格圈或     

Rootstock effects on salt tolerance of irrigated field-grown grapevines (Vitis vinifera L. cv. Sultana) 2. Ion concentrations in leaves and juice

Field vines of cv. Sultana, grown either on their own roots, or grafted to a range of rootstocks, were drip‐irrigated at three salinity levels (0.40, 1.75 and 3.50 dS/m) over a five‐year period. Rootstocks comprised Ramsey, 1103 Paulsen, J17‐69 and 4 hybrids (designated R1, R2, R3 and R4) derived from parentage involving Vitis champini, V. berlandieri and V. vinifera. Concentrations of Cl^‐, Na+, K+, Ca²⁺ and Mg²⁺ were measured in petioles at flowering, and in laminae and grape juice at harvest, in each year of the trial. Vines on all rootstocks accumulated less chloride in either petioles at flowering or in laminae and juice at harvest compared with vines on own roots at all salinity treatments. By inference, all rootstocks behaved as chloride excluders relative to the roots of own‐rooted vines. 1103 Paulsen was the best chloride excluder based on lowest concentrations of accumulated Cl^‐ in petioles, laminae and grape juice at high salinity. Sultana on R3 rootstock at high salinity accumulated more Na+ in both laminae and grape juice (at harvest) than did Sultana on own roots or on any of the other rootstocks. Laminae K+ at harvest time was reduced at high salinity in Sultana on own roots and on all rootstocks. Concentrations of both Cl^‐ and Na+ in petioles at flowering and in laminae and grape juice at harvest showed no significant correlation with either yield (as kg of fresh grapes per vine) or vigour (as measured by fresh weight of one‐year‐old pruning wood per vine) for any salinity treatment. There was however, a strong positive correlation between yield and the subsequent weight of one‐year‐old pruning wood for all salinity treatments. There was also a negative correlation between Na+ concentrations in petioles at flowering and the subsequent weight of one year‐old‐pruning wood from the 0.40 dS/m treatment. Similar negative correlations were found between Na+ concentration in both laminae and grape juice at harvest time, and the subsequent weight of one‐year‐old pruning wood from the 0.40 dS/m treatment (but not from either the 1.75 or 3.50 dS/m treatments). Based on these findings and those from Walker et al. 2002a we conclude that a high innate vigour of a rootstock combined with moderate to high chloride and sodium exclusion ability represents the best combination for salt tolerance in Sultana grapevines as measured by yield at moderate to high salinity.     

THE INFLUENCE OF REDUCED SALT ON THE YIELD, BREAKING FORCE, AND SENSORY CHARACTERISTICS OF CHUNKED AND FORMED HAM

The objective of this study was to examine the effect of reducing sodium chloride (salt) on sensory and processing properties of chunked and formed ham. Chunked and formed hams were made with 0, .5, 1, 1.5 and 2% added salt. Results indicate that the 1.5% salt treatment possessed characteristics closely resembling the 2.0% salt treatment; however, the 1.5% salt treatment had slight reductions in yield, breaking force, and visual acceptability. Reduction of salt from 2.0% to 1.0% resulted in lower yield and sensory characteristics. Additional reductions in the level of salt below 1.0% further depressed yield and sensory characteristics.     

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.