This news article was originally written in Spanish. It has been automatically translated for your convenience. Reasonable efforts have been made to provide an accurate translation, however, no automated translation is perfect nor is it intended to replace a human translator. The original article in Spanish can be viewed at Influencia de los compuestos volátiles y de la calidad estándar en la aceptación del consumidor de diferentes variedades melocotón y nectarina

The study analyzed a total of 11 varieties

Influence of volatile compounds and the standard quality on the acceptance of the consumer of different varieties peach and Nectarine

Echeverria, G.; Cano, j. & Lopez, l. of the Department of postharvest of IRTA; Churches i. of the Experimental Station of Lleida of the IRTA

23/03/2011

on March 23, 2011

In order to increase the satisfaction of the consumers of fruits, it is important to define the sensory quality of peaches and nectarines frescoes on the basis of the acceptance and requirements of consumers. Sensory quality, the taste of the fruits of bone depends on a delicate balance between sugars, acids, and aromatic volatile compounds; as well as a number of additional factors, such as texture of the flesh or ripeness of the fruit.

This work aims to the determination of the parameters of the quality standards, as well as aromatic volatile compounds of eleven varieties of peach and Nectarine and its influence on consumer acceptance. Fruit of the varieties 'early rich', 'sweet dreamcov', 'elegant Lady', 'august Red', 'Royal glory', 'honey royale', 'Venus', 'big top', 'nectagala', 'honey blaze' and 'nectalady' were obtained in the period of commercial harvest and were later analyzed after 2 days of storage in camera at 20 ° C. A regression model was developed by partial squares (PLS1) with the aim of relating the emission of volatile compounds and parameters of the quality standards (variables X), and at the same time the consumer acceptance (variables and). Thus we find the variables that have more influence in the wider acceptance of the consumer and be able to discriminate strains are showing a more balanced assessment of these variables most influential in the acceptance.

The highest scores of acceptance, expressed as a higher level of satisfaction by the consumer, are associated mainly with higher soluble solids content and emissions higher following volatile compounds: d-decalactona, g-dodecalactona, 1-pentanol, octanoato of butyl, penthilus acetate, hexanoato of 2 - 3-phenoxybenzyl-2-(4-ethoxyphenyl)-2-methylpropylether and ethyl octanoato. Varieties with greater acceptance by consumers were among other 'Nectalady', 'honey royale', 'nectagala'; While in the Group of the lesser degree of satisfaction were among other 'Royal Glory', 'elegant Lady', and 'Venus'.

The varieties of 'Nectalady' (to the left) and 'Honey Royale' (on the right) were of the varieties more accepted by the consumer.

Introduction

The parameters of quality and aromatic volatile compounds in peach and Nectarine (Prunus persica l.) play an important role in the satisfaction of the consumer greatly influencing their consumption. The taste, aroma, texture and appearance, or appearance, are considered the most important attributes of quality in peach and Nectarine. The taste is related to water soluble compounds and aroma it cause volatile compounds with pleasant smell.

In recent years, with the aim of offering consumers a wider range in terms of sensory perceptions, types of fruit and ripening times, peach and Nectarine production has increased considerably in Spain producing 1.033.000 tons in 2010 and an area of 78,500 hectares (churches et to the.)(2011). The largest increase occurred in Nectarine thanks to the planting of new varieties, generally high colouring, with different colors (yellow and white) flesh, forms of fruit (spherical, flat), concentrations of soluble solids (CSS), titulable acidity (AT) (high)(, medium or low) (churches and Echeverría, 2009) and taste. Particular importance have been varieties of sweet taste, in the case of the Nectarine, peach and the flat peach where varietal innovation has been very remarkable (churches et to the., 2011). Of fact and based on the results of the European project Isafruit, this type of fruit is preferred (72% of consumers) in different countries of the European Union. Despite the important varietal innovation, the consumption of peach and Nectarine in the EU has remained stable and even declined (Liverani et al., 2002;) Hilaire and Mathieu, 2004; (Pérez and Pollack, 2009).

A total of eleven varieties of peaches and nectarines, were studied. Among them was found which had a lesser degree of consumer acceptance were the Group of the lesser degree of satisfaction were among other 'Royal Glory' (left), "Elegant Lady" (Center), and 'Venus' (right).

Consumers indicate as main causes of the low power lack of taste, inappropriate state of maturity (immature fruit), the varying quality and lack of identification in the linear of sales

Spain current consumption stands at around 4 kg/habitante-año and is stabilized, having decreased by 46% since 1989 (churches, 2010). Consumers identified as main causes of the low consumption lack of taste, inappropriate state of maturity (immature fruit), the varying quality and lack of identification on the display shelves of sale depending on the taste of the fruit (sweet or acid). Improve consumer satisfaction is the key to increase the consumption and therefore it is important to know the characteristics of the fruit that influence acceptance of consumers. Some relationships between the different attributes of quality of the fruits of peach have already been studied. Bassi and Selli (1990) investigated the use of chemical determinations (total sugars, acids and phenolic compounds) and sensory (taste and astringency) in the evaluation of the quality of peach and different varieties of apricot, while Harker et to the. (2002) compared sensory and instrumental measurements in Apple.

This paper focuses on the evaluation of parameters of quality standards and the emission of volatile compounds in eleven varieties of peach and Nectarine and its influence on the acceptance of the consumer.

Materials and methods: plant material

Fruits of varieties, sorted by order of ripening of peach: 'early rich', 'Royal glory', 'sweet dream', "Elegant Lady"; and nectarines: 'big top', 'honey blaze', 'honey royale', 'Venus', 'nectagala', 'august Red' and 'necta Lady', were obtained from commercial plots located in the area of Alcarràs (Segrià-Lleida, NE of Spain) at the time of the commercial harvesting of them during the summer of 2009. All plantation was used as pattern hybrid peach x almond GF-677 and framework of plantation of 5 x 3 m. The parameters of the quality standards and emission of volatile compounds of these fruits were measured at the time of the commercial collection (H) and after 48 hours of storage at 20 ° C (H+48), as described below. Also found acceptance by consumers after 48 hours at 20 ° C.

Extraction and analysis of volatile compounds

On each date of sampling, 6 kg of fruit (2 kg x repeat 3 repetitions) of every variety were selected for the analysis of volatile compounds, both in the harvest and after 48 hours of storage at 20 ° C. Intact fruits were placed in a container of glass (Pyrex 8 l) through which became circular synthetic airflow (150 ml/min) for 1 hour. The resulting effluent is passed through tubes of stainless steel (3.5 inch (89 mm) x 0.25 inches (6.4 mm) outer diameter) containing a bed-absorbent of approximately 350 mg of Tenax TA 1TD / Carbograph (Markes International Limited Llantrisant United Kingdom) (Figure 1). The desorption was carried out in a team of thermal desorption Unity (Markes International Limited, Llantrisant, United Kingdom). The absorbent tube was inserted into the team of thermal desorption Unity (Markes International Limited, Llantrisant, United Kingdom) (Figure 2). Volatile compounds were separated using the following programming of temperature: 40 ° C (1 minute), 115 ° C at a speed of 2.5 ° C/min, and finally to 225 ° C to 8 ° C/min for 10 minutes. The injector and detector remained at 240 ° C. The results were expressed as in ng/kg.

Figure 1: Details of the ballot box for the extraction of volatile compounds.

Figure 2: Details of the chromatograph and the team of thermal desorption.

Physico-chemical parameters

Thirty fruits were individually analyzed to evaluate the following quality parameters: content of soluble solids (CSS), titulable (AT) acidity, firmness of flesh (firmness), color of skin and flesh. The color was expressed on the basis of the tone (degrees) both of the exposed face of the skin of the fruit (tone (CE)) and the pulp (tone (CE)), and the shaded face (tone (CS)) and pulp (tone (CS). Such determinations were based on the methodology described churches and Echeverria, 2009.

Thirty fruits were individually analyzed to evaluate the following quality parameters: content of soluble solids (CSS), titulable (AT) acidity, firmness of flesh (firmness), color of skin and flesh

Acceptance of the consumer

The degree of acceptance of the fruit was evaluated by a panel of 53 regular users of peaches and nectarines on the basis of the methodology described by Echeverria et to the. (2008). The consumer panel was asked to it puntuará each variety according to a test of verbal hedónica 9-point scale (1: I dislike very much,..., 9: I very pleased). At each assessment panel compare fruits of a certain time of collection. Consumers were volunteer staff working in the IRTA Research Centre, as well as teachers and students of the University of Lleida.

Statistical analysis

The results were analyzed by means of analysis of variance (GLM Anova), followed by the test of minimum significant difference (LSD) with P<0,05. la anova se realizó de acuerdo a los procedimientos del sas / stat versión 9.1 (sas institute inc., 2004). unscrambler vers. 9.1.2. (camo asa, 2004) se utilizó para el desarrollo de un modelo de regresión lineal por mínimos cuadrados parciales (pls). este pls se ha ejecutado en un intento de relacionar las emisiones de compuestos volátiles y los parámetros estándar de calidad (variables x) con la aceptación del consumidor (variable y), con el fin de encontrar las variables que más peso tuvieron y así discriminar entre cultivares. la="" anova="" se="" realizó="" de="" acuerdo="" a="" los="" procedimientos="" del="" sas="" stat="" versión="" 9.1="" (sas="" institute="" inc.,="" 2004).="" unscrambler="" vers.="" 9.1.2.="" (camo="" asa,="" 2004)="" se="" utilizó="" para="" el="" desarrollo="" de="" un="" modelo="" de="" regresión="" lineal="" por="" mínimos="" cuadrados="" parciales="" (pls).="" este="" pls="" se="" ha="" ejecutado="" en="" un="" intento="" de="" relacionar="" las="" emisiones="" de="" compuestos="" volátiles="" y="" los="" parámetros="" estándar="" de="" calidad="" (variables="" x)="" con="" la="" aceptación="" del="" consumidor="" (variable="" y),="" con="" el="" fin="" de="" encontrar="" las="" variables="" que="" más="" peso="" tuvieron="" y="" así="" discriminar="" entre="">

Results and discussion

There were no significant differences in CSS, AT and color in any of the tested varieties (table 1). However, significant differences in the firm. A significant loss of firmness was detected between the fruits of harvest and the corresponding after 48 hours of conservation at 20 ° C for the varieties 'elegant Lady', 'nectalady', 'august Red' and 'Venus'. For the rest of the tested varieties, we detected no significant loss of firmness.

Table 1: parameters of the quality standards of the 11 varieties analyzed in the harvest period and after 48 hours at 20 ° C in 2009.

Scores of the acceptance by the consumer for 11 varieties analyzed are shown in table 2. It notes that higher consumer acceptance scores were obtained for the nectarines of the variety 'nectalady'. In general, the degree of acceptance was acceptable (greater than 5 on a hedónica scale of 9-point) for all varieties except "Elegant Lady', 'Royal glory' and 'early rich'.

Table 2: acceptance of consumers in 11 varieties analyzed in harvest date + 48 h. at 20 ° C.

A total of 43 volatile compounds were identified by chromatography of gases-masas (GC-MS) in 11 varieties, being the average of volatile by variety of 30

A total of 43 volatile compounds were identified by chromatography of gases-masas (GC-MS) in 11 varieties. The volatile by variety averaged 30, with a range that ranged from 23 to 37 depending on the variety. Different volatile compounds were widely distributed among the varieties, but only a small number of them (5-9) contributed to more than 60% of the total content. Many volatile compounds have already been identified in other varieties of peach (Aubert and Milhet, 2007). The aromatic profiles of all varieties are 16 common volatile compounds which provide them with floral and fruity aromas (hexilo acetate, 2-metilpropanoato of 2-metilbutilo, 2-metilbutilo acetate, butyl acetate, 2-3-phenoxybenzyl-2-(4-ethoxyphenyl)-2-methylpropylether acetate, and propyl acetate)(, 2-ethyl-1-hexanol and linalool), with sour notes (hexenal, benzoic acid and acetic acid) and nuances to almond by the presence of benzaldehyde (data not shown).

Figure 3 shows a model of linear regression by least squares partial (PLS), which was made to relate the acceptance of the consumer (variable and) with standard quality parameters and emission of volatile compounds (variable X). The parameters of the quality standards and emission of volatile compounds represent up to 89% of the total variability in the acceptance of the consumer. The variables that most influenced the acceptance of consumers were the CSS (see the largest bar) and following volatile compounds: d-decalactona, g-dodecalactona, 1-pentanol, octanoato of butyl, penthilus acetate and 2-3-phenoxybenzyl-2-(4-ethoxyphenyl)-2-methylpropylether hexanoato. These compounds increases the specific fruity aroma to Peach. The important influence of some volatile compounds and the content of soluble solids (CSS) in the consumer satisfaction also is has been noted by other authors (Hilaire et to the., 2000;) Hilaire et al., 2004, churches and Echeverría, 2009; Ortiz et 2009).

Figure 3: Model of linear regression by partial least-squares of all samples. The PC1 regression coefficients vs. From PC2 in the PLS obtained in terms of consumer acceptance.

Thanks

J. Cano is a beneficiary of a grant from the Agència of Gestió D'ajuts D'universitats i Recerca (Agaur), Generalitat de Catalunya (Spain). This work has been done thanks to funding by the National Institute of agrarian investigation of Spain (Inia) through the RTA 2008-00055-00-00 draft.

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