Effects of ethephon, methanol, ethanol and girdling treatments on berry maturity and colour development in Cardinal table grapes

To hasten berry maturity and improve skin colour, the early-season table grape variety Cardinal was treated (post veraison) with a bunch + foliar spray using either 240 or 480 mg/L ethephon, as well as with 30% methanol, 30% ethanol (v/v); or by girdling. Treatment effects were evaluated in a randomised experimental design, with 10 replications of one plant per plot, down a single row. Ethephon at 480 mg/L applied twice, on July 2 when 5% of the berries showed colouring and on July 9 when 20% of the berries developed partial colour, increased total soluble solids, °Brix/titratable acidity and skin colour. Girdling, methanol and ethanol also increased total soluble solids and berry colouration and caused faster ripening. Ethephon at 480 mg/L was generally the most effective means of hastening ripening and improving colour.     

The sensory evaluation of jonathan and delicious apples treated with the growth regulator ethephon

Jonathan and Delicious apples were sprayed with the growth regulator Ethephon at concentrations of 250 and 500 parts 10^?6. Fruits from each spray treatment were harvested sequentially in three stages, approximately 1, 2 and 3 weeks after treatment; then submitted to panels for sensory evaluation. Ethephon significantly enhanced hedonic scores for skin colour, flavour and general acceptability of Jonathan apples regardless of the harvest time, but had no significant effect on texture. The skin colour of Delicious apples was significantly improved by Ethephon application (regardless of harvest time) but there was no significant effect on flavour or general acceptability and texture was significantly impaired.     

Yield,earliness and fruit quality of pepino clones and their hybrids in the autumn–winter cycle

The success of the pepino (Solanum muricatum Aiton) as a new crop for intensive horticultural areas relies on shortening the growing cycle and on securing a high standard of fruit quality. Irrigation with saline water and ethephon sprayings could be useful in achieving these goals. Two consecutive pepino crops consisting of two hybrids and their four parents were grown in the autumn–winter cycle. Plants were irrigated with water having electrical conductivities of 3 or 8 dS m⁻¹ and full sized fruits were sprayed with ethephon at 0 or 500 mg l⁻¹ . Salinity reduced yield and fruit size, although this effect was less important in the hybrids, which showed heterosis for yield characters. Overall, yields and fruit size of hybrids irrigated with saline water were greater than in the parents irrigated with non‐saline water. Ethephon had no effect on yield characters. Salinity and ethephon improved earliness. In most clones combination of salinity and ethephon shortened the growing cycle by 1 month. Salinity improved fruit quality as it increased the soluble solids content (SSC) and dry matter (DM) in all clones, and titratable acidity (TA) in some cases. Ethephon sprayings had no marked effects on quality characters, except for parental clone 9‐1 in which ethephon treated fruits had a lower SSC and TA. Organoleptic tests conducted on the best flavoured clones (0‐8 and 6‐10) showed that salinity improved fruit aroma and flavour although not texture, while ethephon had no effects. Results show that irrigation with saline water and ethephon sprayings improve earliness and fruit quality without dramatic yield depressions, especially in the hybrid clones. © 1999 Society of Chemical Industry     

°BRIX/ACID RATIO AS A PREDICTOR OF CONSUMER ACCEPTABILITY OF CRIMSON SEEDLESS TABLE GRAPES

ABSTRACT

Harvesting at correct time is essential for the supply of quality grapes. There is no standard method to determine the proper time of harvesting for table grapes. The applicability of objective measurements such as soluble solids concentration (°Brix), acid contents (titratable acidity) and °Brix/acid ratio of Crimson Seedless table grapes were evaluated as predictors of quality in terms of consumer acceptability. Crimson Seedless table grapes were harvested from two locations in Western Australia at weekly intervals for 5 weeks. The samples were density sorted to get berries of different maturity levels. Objective measurements and sensory evaluation (panel of 63 judges) were conducted. There were significant (P ≤ 0.05) differences in the degree of liking among grapes of 16.0–17.0, 17.1–18.0 and 19.1–20.0°Brix. Consumer liking of grapes substantially changed with a change in acidity. The data revealed correlation coefficients of determination (r²) of 0.58, 0.79 and 0.85 between overall consumer acceptability and °Brix, acidity, and °Brix/acid ratio, respectively. °Brix/acid ratio was found to be the best objective measurement that reflected the consumer acceptability and can be used as a reliable tool to determine the optimum harvesting stage of Crimson Seedless table grapes.

PRACTICAL APPLICATIONS

Crimson Seedless table grapes have been successfully grown in Australia since 1994, and they are gaining popularity with consumers day by day. However, means of determining proper time to harvest has not yet been established. This study, by examining the relationship between instrumental measurements and human perception of sensory characteristics of Crimson Seedless table grapes, will provide a simple but reliable instrumental method to predict the optimum harvest stage of Crimson Seedless table grapes. This will help in providing a quality product to the consumers while helping growers to get better return out of their produce.     

Optimization of oven toasting for improving crispness and other quality attributes of ready to eat potato-soy snack using response surface methodology

Ready-to-eat potato-soy snacks were developed with high temperature short time air puffing process followed by oven toasting for increasing crispness. Oven toasting experiments were conducted with varying temperature (85.86–114.14 °C) and time (12.69–35.31 min) based on central composite rotatable design. The final product was evaluated in terms of quality attributes such as crispness, moisture content, ascorbic acid loss, colour (L and ΔE) values and overall acceptability. The optimum product qualities in terms of crispness (38.7), moisture content (3.35%, db), ascorbic acid loss (20.87%, db), L value (52.03), ΔE (8.60) and overall acceptability (7.8) were obtained at temperature of 104.4 °C and time of 27.9 min.     

Rice bran-soy blends as protein supplements in cookies

The effect of incorporating one of three stabilized full-fat rice brans in combination with each of four soy ingredients in a sugar-snap cookie was investigated. The four soy ingredients in a sugar-snap cookie were two soyflours (full-fat and defatted), a soy concentrate and a soy isolate. Rice bran and soy were added in place of wheat flour to increase protein content from 6% to a minimum of 9%, and the cookies were compared with each other and with a 100% wheat flour cookie. Quality characteristics evaluated included protein, spread, physical texture and colour, and sensory preference by ranking for colour, crispness and flavour. In general, the rice bran-soy cookies had less spread (even with added shortening, water and emulsifier), were less crisp and more chewy, and were somewhat darker in colour than the 100% wheat flour cookie. The soy isolate, USDA and Protex 20-S cookies were as acceptable in colour, crispness and flavour as the control.     

Effects of variety and stage of fruit ripeness on the physicochemical and sensory characteristics of deep‐fat‐fried banana chips

The quality of banana chips prepared from two different varieties of banana, Pisang Abu and Pisang Nangka, at the ‘green’ and ‘trace of yellow’ stages of ripeness was studied. The fruits were peeled, sliced to a thickness of 2 mm and deep‐fat fried in refined, bleached and deodorised (RBD) palm olein at 180 ± 5 °C for 3 min. The quality parameters determined for fresh bananas were total soluble solids, pH, acidity, carbohydrate, sugar content, fat, protein, moisture content, ash, fibre, colour and fruit firmness. The results showed that Abu had a higher carbohydrate content than Nangka at both stages of ripeness before frying. No sucrose was detected in Nangka. The quality parameters determined after deep‐fat frying were moisture content, water activity, oil absorption, crispness and sensory evaluation. The moisture content and water activity of Abu chips were lower than those of Nangka chips. The texture of chips prepared from Abu at stage ‘green’ showed more crispness than the other three samples. Sensory evaluation showed that chips prepared from Abu at both stages of ripeness presented better colour, flavour, odour, texture and overall acceptability than those prepared from Nangka. Based on the matrix of correlation coefficients, fresh bananas with higher fruit firmness and carbohydrate content gave banana chips with higher crispness and oil absorption. © 2001 Society of Chemical Industry     

Exclusion of sunlight from Shiraz grapes alters wine colour, tannin and sensory properties

The aim of this study was to determine how changes in grape composition brought about by artificial shading (sunlight exclusion) influence wine properties including colour, flavonoid composition and sensory attributes. Prior to flowering, bunches of Shiraz grapes were enclosed in boxes designed to eliminate light without altering bunch temperature and humidity. This artificial bunch shading had little effect on berry ripening and accumulation of sugar but at harvest the shaded bunches had smaller berries and higher seed weight, juice pH and titratable acidity. The amount of anthocyanins in the fruit was not changed significantly but anthocyanin composition in the shaded berries was shifted towards dioxygenated anthocyanins (the glucosides of cyanidin and peonidin derivatives). Shaded fruit had increased seed tannins and decreased skin tannins but the largest relative change in flavonoids was a marked decrease in flavonols in the shaded fruit, similar to previous studies. Wines made from shaded fruit had lower wine colour density, total phenolics, anthocyanins and tannins when the wine was bottled and after ageing for up to three years. Analysis of potential flavour compounds following acid hydrolysis indicated that the wines made from shaded fruit had decreased levels of glycosides of β-damascenone and 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN). Sensory analysis of the wines indicated no significant difference in aroma attributes but the wines made from shaded fruit were rated lower for astringency, fruit flavour and flavour persistence in-mouth sensory attributes. The results indicate that extreme shading of Shiraz fruit can decrease wine colour, anthocyanins and tannins as well as altering sensory attributes.     

Minor ingredients of edible table spreads

The minor ingredients of edible table spreads exhibit important functional and, in some instances, nutritional properties which may be important to the consumer acceptability of commercially available products depending on market positioning. In addition, they may hold the key to the successful development of a new generation of edible table spreads which contain unhydrogenated fish oils andlor potentially probiotic lactic acid bacteria. This paper describes aspects of the selection, use and functionality of minor ingredients in edible table spreads including colourings, flavourings, flavour enhancers, sweeteners, antioxidants, antioxidant synergists and optional ingredients such as vitamins. Antifoaming agents, although permitted in edible table spreads, are not discussed in view of their rare commercial use. Additive free products can be produced that are microbiologically safe and nutritious but they lack consumer acceptability in terms of colour and flavour .     

Effect of pasteurisation on sensory quality of natural soursop puree under different storage conditions

Pasteurisation effects on natural soursop (Annona muricata L.) puree were evaluated in terms of appearance, colour, flavour, odour, consistency and overall acceptability for 12 weeks. The packaging and storage temperature combinations used were laminated aluminium foil (LAF), lacquered can (LC) and high density polyethylene plastic bottle (HDPE) at ambient temperature (28–38°C), 15, 4 and −20°C. Results showed pasteurisation at 79°C for 69 s significantly improved the sensory colour, flavour, appearance and overall acceptability of the puree. Pasteurised puree packed in LAF at 4°C had the highest score for almost every attribute evaluated. Overall, all samples were found acceptable by judges during the 12 week storage period. The better stability, in terms of colour, consistency and flavour characteristics, of pasteurised puree packed in foil at 4°C than the frozen control could be an additional and cheap advantage for storage and transport.     

Multivariate classification of wines from seven clones of Monastrell grapes

The enological characteristics of different clones of Monastrell grapes have been studied. The wines obtained from different clones were subjected to chemical analyses, including the determination of organic acids, colour characteristics and mineral elements. Significant differences were found among clones. To check if these analytical parameters could correctly classify the wine samples, multivariate statistical analysis was done. Cluster and principal component analysis classified correctly samples belonging to the same clone. © 2000 Society of Chemical Industry     

Influence of processing method and holding time on the physical and sensory qualities of cooked marinated chicken breast fillets

The effects of different processing methods and marinating times on the physical and sensory properties of cooked Chinese-style marinated chicken breast fillets were investigated. Factors including marinade treatment (CM = coarse + mixing; CMH = coarse + mixing + homogenizing; FM = fine + mixing; FMH = fine + mixing + homogenizing) marinating method (immersion only, injection and immersion, tumbling) and holding time (0, 18 h) were applied to samples before cooking under simulated commercial conditions. Marinade absorption, cooking loss, maximum force and surface colour (L*, a*, b* values) were measured. Sensory properties including colour, colour penetration, aroma, toughness, flavour acceptability, saltiness, sourness, sweetness, juiciness and overall acceptability were also evaluated using 20 naïve assessors. Homogenized marinades, CMH and FMH increased surface CIE a* (redness) and b* (yellowness) values. Conversely, CM had the lowest colour penetration. Employing a tumbling method and an 18 h holding period was found to be positively correlated with most sensory attributes measured; surface colour, colour penetration, aroma, saltiness and sweetness. The individual effect of tumbling produced a significantly (P < 0.05) higher overall acceptability, whereas samples held for 18 h were least preferred by the assessors due to lower flavour and overall acceptability scores.     

Rootstock and salinity effects on rates of berry maturation, ion accumulation and colour development in Shiraz grapes

Shiraz grapevines on either their own roots, or on the rootstocks Ramsey, 1103 Paulsen, 140 Ruggeri or 101–14, were grown at two separate sites within the Murray‐Darling viticultural region with similar irrigation regimes but with an irrigation water salinity of either 0.43 dS/m (low salinity site) or 2.3 dS/m (high salinity site). Rootstock effects on grape berry development, ion concentrations, soluble solids and acidity were followed during one season. Wines were also made and compared using spectral analysis and sensory evaluation. Rootstock effects that were common across both sites were (1) a close relationship between K+and soluble solids accumulation in developing grape berries which commenced at the onset of veraison and was indicative of a link between K+and sucrose transport in the phloem, and (2), higher wine K+, pH and colour hue for all rootstocks with one exception, namely 101–14 at high salinity where 101–14 responded similarly to own roots. Juice K+, pH and loss of K+from juice during winemaking were highest for grapes from the high salinity site. Mean berry weight was smaller and the range in berry size across rootstocks was narrower at the saline site. The narrower range in berry sizes may have contributed to fewer rootstock effects on wine spectral characteristics at high salinity. There was no effect of rootstock on CO₂ assimilation rate or stomatal conductance at either site, although intrinsic leaf‐based water‐use efficiency measured as A/g was 50% higher at the saline site. All treatments exhibited berry shrivel at maturity, but the extent was smaller at high salinity. Slower development of berry colour during veraison was observed on some rootstocks, for example 101–14, and while unrelated to canopy size per se, a higher leaf‐to‐fruit ratio for 101–14 may have been a factor. Slower berry colour development during veraison had no bearing on the colour density of wine made from the harvested grapes.     

Optimisation of processing variables in the preparation of sweet potato chips using response surface methodology

Models capable of predicting the product quality of sweet potato chips have been developed using response surface methodology and used to determine the optimum processing conditions. Moisture loss, oil uptake, crispness (measured using a bending-snapping test in the TA.XT2 Texture Analyser), and sensory attributes such as colour, flavour, and texture were used to assess the product quality in the preparation of sweet potato chips. The optimum conditions which were attained for maximum moisture loss (11.65% on wet basis), minimum oil uptake (2.57%), crispness (794.37 g), colour score (7), flavour score (7) and texture score (7) were: frying temperature, 174.7 °C; salt concentration, 0.45%; citric acid concentration, 0.37%; potassium metabisulphite concentration, 0.65%; and frying time, 26 s.     

Effects of fat level, oat fibre and carrageenan on frankfurters formulated with 5, 12 and 30% fat

The effects of fat level (5, 12 and 30%), carrageenan and oat fibre on the hydration/binding properties, colour and flavour characteristics of frankfurters were investigated. Decreasing the fat content from 30% to 5% significantly increased cook loss and decreased water holding capacity and emulsion stability. Reduced-fat products were also darker and redder compared with the 30% fat controls. Addition of carrageenan or oat fibre reduced cook loss and increased both water holding capacity and emulsion stability. Sensory evaluation indicated that decreasing fat from 30% to 5% increased the intensity of smokiness, spiciness and saltiness and reduced the overall acceptability of the flavour. Carrageenan or oat fibre did not alter the colour of the frankfurters and neither ingredient had a significant effect on the flavour characteristics assessed. The results demonstrate that carrageenan or oat fibre can partially offset some of the changes which occur in low-fat frankfurters when added water replaces fat and protein level is constant.     

ABA和乙烯利处理对京优葡萄果皮花色苷和果实品质的影响

以京优葡萄为试材,研究不同浓度ABA和乙烯利处理果穗对果皮花色苷含量及果实品质的影响.结果表明,ABA和乙烯利处理皆能促进果实软化、有机酸降解、可溶性固形物和果皮色素积累,具有促进果实成熟的作用.乙烯利软化果实的效果明显好于ABA,但促进果实可溶性固形物积累的效果弱于ABA.300 mg/L ABA和乙烯利处理的催熟效果不明显,仅能使果实提前3～6d成熟;高浓度乙烯利处理(600 mg/L和900 mg/L)可以有效促进果实成熟,但会导致着色不良、裂果和落果等问题;600 mg/LABA处理效果最佳,可以使果实提前13～16 d成熟,且果实理化指标皆能满足商品要求.     

The changes in black tea quality due to variations of plucking standard and fermentation time

Catechin levels in green leaf, total theaflavins, brightness, thearubigins, colour, flavour index and sensory evaluation decrease with coarse plucking standard in clone 6/8. The sum of Group I volatile flavour compounds and C₆ aldehydes and alcohols, in particular, increases with coarse plucking standard. The sum of Group II did not follow a particular pattern, but flavour index decreased with coarse plucking standards. The decrease in total theaflavin levels was due to the decrease in all the individual theaflavins. Although all the individual theaflavin levels decreased with coarse plucking standards, the decrease was greater in galloylated theaflavins, especially in theaflavin digallate, compared with simple theaflavin. Short fermentation times produced black teas with higher brightness and flavour index, but lower theaflavins, thearubigins and colour, irrespective of plucking standard. Total theaflavins reached a maximum after 90 min of fermentation, irrespective of the plucking standard, whereas ungalloylated theaflavin levels decreased with extended fermentation duration at all plucking standards, theaflavin-3-gallate and theaflavin-3, 3’-digallate levels increased, resulting in the increase in theaflavin digallate equivalent. Brightness and flavour index decreased while thearubigins, colour, and Groups I and II volatile flavour compound levels increased with long fermentation.     

Effect of low-temperature preservation on the quality of vacuum-packaged dry-cured ham: Refrigerated boneless ham and frozen ham cuts

The effect of storage on dry-cured ham quality was studied. Sixteen vacuum-packaged boneless dry-cured hams and sixteen vacuum-packaged dry-cured ham cuts were stored in darkness under refrigeration (4±2°C; 8 months) or freezing (-18±1°C; 24 months), respectively. Instrumental colour and texture, physico-chemical and biochemical parameters, sensory profile and consumer acceptability and purchase satisfaction were measured throughout storage. The overall quality of refrigerated boneless dry-cured hams and frozen dry-cured ham cuts showed only limited changes throughout long-term storage. Significant changes involved loss of odour and flavour, increased adhesiveness and modification of hardness, the Semimembranosus muscle became tender while Biceps femoris became harder, leading to a higher textural homogeneity. In agreement with those changes, the overall acceptability assessed by a trained panel decreased throughout storage, though this was significant regarding only frozen hams. However, consumer evaluation of acceptability, as well as satisfaction with hypothetical purchasing, did not vary significantly throughout storage.     

Pectin-derived oligosaccharides increase color and anthocyanin content in Flame Seedless grapes

BACKGROUND: Grapes grown in warm weather do not develop a desirable red color and require the use of products to enhance berry color. Pectin‐derived oligosaccharides (PDOs) have been shown to have a role in various responses including plant defense, growth and development. In this work a mixture of PDOs with 3–20 degrees of polymerization was applied to Vitis vinifera cv. Flame Seedless grapes under field conditions and compared to the effects of ethephon (an ethylene‐releasing compound). The effect of treatments on grape color, anthocyanin content and phenylalanine ammonia lyase (PAL) mRNA levels was evaluated. RESULTS: PDOs treatment increased berry color measured by the Color Index of Red Grapes (CIRG) and anthocyanin content, compared to ethephon and untreated berries (control); 1.5, 1 and 0.5 mg mL^?1 PDOs increased berry color by 30%, 27% and 26%, respectively, when compared to control berries. Levels of PAL mRNA accumulating in berries treated with PDOs were elevated within the first 24 h of treatment. CONCLUSIONS: PDOs enhanced the color and anthocyanin content of Flame Seedless grape berries possibly due by the induction of PAL mRNA expression. The results demonstrated that PDOs can be used to improve fruit quality aspects such as berry skin color. Copyright © 2011 Society of Chemical Industry