Organic Grape Research Articles

Organic Consumers' Profile and Their Willingness to Pay (WTP) for Selected Organic Food Products in Greece

The adoption of different food quality assurance schemes by the EU, such as the organic label, has been a response to the growing demand for certified quality food products among the European consumers. Several useful benefits have been claimed for these schemes, including their value as marketing strategies. The present study develops at a two-fold level: first, it attempts to offer more insights into the Greek organic consumer profile, using a nationally representative sample of 1,612 households. Second, the study examines the effectiveness of the organic label as a marketing strategic orientation, given that addressing the highly motivated, quality conscious consumer is the core objective of any food quality assurance policy. The use of conjoint analysis in exploring organic buyers' Willingness to Pay (WTP) for a variety of organic products (olive oil, raisins, bread, oranges and wine from organic grapes) is selected as the most appropriate approach to that target.

Control of spoilage in table grapes

Purpose of the review: Diverse means to control decay and spoilage of table grapes during storage have been described in numerous research papers that were published recently. The purpose of this review is to describe some of the major publications in this field and to point out on their advantages and shortcoming. Main findings: Studies pertaining to the control of postharvest decay of table grapes and prevention of quality losses were categorised according to the general approach used (dry, wet, physical). Of the “dry” treatments, active modified atmosphere packaging (MAP), which includes volatiles for continuous control of decay, seems to be an attractive approach. Of the methods that can be directly integrated into current commercial practices, biofumigation with the fungus Muscodor albus warrants further assessment. Wet treatments have some inherent disadvantages because they require additional handling of the grapes. However, postharvest treatments with disinfectants such as ethanol can effectively control decay during cold storage of medium duration. These wet treatments can be useful to remove visible deposits of soil and pesticides, to prolong the storage life of organic grapes, and to disinfect and retard the decay of “ready-to-eat” grape products. Advantages of ethanol are that its efficacy can be enhanced by heat, sorbates, or MAP, and that it dries faster than other wet treatments. Directions for future research: There are specific issues to be addressed for every technology to be considered. However, many of the studies published on the control of spoilage of table grapes report results using specific cultivars, storage of limited duration, or small scale experiments. Any technology further to be considered must be confirmed in large-scale, semi-commercial experiments to reveal potential pitfalls and limitations and to evaluate all aspects of fruit quality. In addition, a cost analysis of each technology is essential.

(378) Weed Management in Organic Grapes

Iowa was the sixth largest producer of grapes in the United States in the early 1900s, with 24,000 ha under production. The rapid expansion of petrochemicals post-World War II and grape's sensitivity to 2,4-D herbicides reduced vineyard size in Iowa to 28 ha in 2001. Recent state governmental support for organic fruit research and viticulture in general has led to the expansion of the grape and wine industry in Iowa. As of 2001, 5883 ha of organic grapes were produced in the United States. Challenges to organic grape production in the Midwest include diseases and weeds. The cultivation of American grape cultivars is essential in organic viticulture in the Midwest, including cultivars that are relatively cold hardy and disease tolerant. From 2003 to 2004, we experimented on-farm at Kirkland Vineyards, Norwalk, Iowa, with methods of organically approved weed management. Three replications of plots consisting of five vines each of `Marechal Foch' were laid out in 2003 in a completely randomized design in a 1-year-old vineyard. Treatments consisted of wood chips, wood chips plus vinegar herbicide (All-Down™, Summer Set Co., Chaska, Minn.), and mowing when weeds and groundcover reached 15 cm. Wood chips decreased weed load significantly over mowing alone, but wood chips plus vinegar herbicide provided the most control over 2 years of the experiment. There was a trend toward greater plant height in the wood chip treatment, but no significant differences in plant height were observed among treatments.

Examination of nitrogenous compounds in Hungarian bio-musts

There has not been any research done on the musts from organic grapes. As a result of the special technologies in organic farming we can expect bio-musts to have a different quantitative and qualitative composition of nitrogen compounds from that of traditional musts. In our present essay we deal with the tests of nitrogenous compounds (assimilable nitrogen content, aminoacid, biogenic amine content) in musts from Hungary's bio-wine cellars. Our results show that the change in procedures has resulted in neither quantitative nor qualitative changes in the nitrogenous compounds of bio-musts.

Comparison of the biogenic amine content of traditional and bio-wines

There has been a growing tendency in organic farming in recent years, in which organic grape growing and the production of bio­wine are also significant. The literature on bio-wine is rather limited, that is why we consider it really important to contribute to the data. As a result of the special conditions in organic farming we can expect bio-wines to have a different composition of nitrogen compounds from that of traditional wines. Biogenic amines could thus specially characterize bio-wines. In our research we compared the biogenic amine content of wines produced using organic methods and of those where traditional procedures were used. Our measurements have proved that it is not possible to clearly distinguish bio-wines from wines produced with traditional methods on the basis of amine content.

Antioxidant activities of organic grape, pomace, juice, must, wine and their correlation with phenolic content

SummaryThe highest values of antioxidant activity (AOA), inhibition of low‐density lipoproteins (LDL‐diene, LDL‐MDA) and total phenols were determined in pomace (82.30 and 82.60%), grapes (68.91%) and must [2750 mg L−1 gallic acid equivalents (GAE)], respectively. For all parameters (AOA, iLDL‐diene, iLDL‐MDA, total phenols) the highest values were obtained in Cabernet Sauvignon and Merlot grape varieties. Positive correlations were determined between AOA and iLDL‐diene (r = 0.809); AOA and total phenols (r = 0.528); total phenols and iLDL‐diene (r = 0.451) with significance of P < 0.005. The results of principal component analysis demonstrated that the location of iLDL‐diene and AOA is the same for pomace, must and red wines. The total phenols are found in the same place in red wines, red grapes, pomace and must. The results emphasize the importance of must, pomace and red wine for inhibiting LDL‐oxidation.

Effect of Organic Farming Practices on the Level of Latent Polyphenol Oxidase in Grapes

: The levels of polyphenol oxidase (PPO) in organic as compared with conventional Monastrell grapes were examined in this study. The enzyme was partially purified using the Triton X-114 method, and in both cases it was obtained in a latent state, being activated by different methods (acid shocking, detergents, and proteases). PPO purified from both organic and conventional Monastrell grapes had the same isoenzymatic form, appearing as the same single band in polyacrylamide gel electrophoresis. However, diphenolase activity of activated PPO in organic grapes was 2 times higher than in conventional grapes, independent of the activation method used. Moreover, the proteolytic activation method, using trypsin, was the most effective for this latent PPO.

Chemical parameters, biologically active polyphenols and sensory characteristics of some Italian organic wines

This paper describes 23 commercial Italian wines, made from organic grapes, by their chemical parameters, biologically active polyphenol concentrations and sensory analysis. Our data show inconsistent differences in the trans-resveratrol and p-coumaric acid contents in comparison with non-organic wine, with the exception of quercetin concentrations in Chianti samples. Furthermore, the chemical analyses and sensory data of organic wines did not significantly differ from those previously cited. In general the organic wines display satisfactory sensory properties such as flavour intensity, body and a general acceptance.

ORGANIC APPLE AND GRAPE PERFORMANCE IN THE MIDWESTERN U.S.

ORGANIC APPLE AND GRAPE PERFORMANCE IN THE MIDWESTERN U.S.

Wine produced by organic grapes in Greece: using means—end chains analysis to reveal organic buyers' purchasing motives in comparison to the non-buyers

The present study attempts to offer more insights into the Greek wine market with emphasis on wines produced from organically grown grapes by relating wine choice to consumers' personal value structure. With the use of a qualitative sample and applying the Means–end Chains methodology and the corresponding “laddering” interviewing technique, it attempts first to reveal the way basic motives are linked to wine shopping behaviour of consumers and the way wine purchase-relevant knowledge is stored and organised in their memory in relation to their personal values. Then, by discriminating between organic food buyers and non-buyers, the study identifies motivational and cognitive discriminating differences between the two consumer types, which can offer a solid explanation as to their distinctive purchasing behaviour in respect of the organic products.

Organic viticulture in West Germany

We present results from a survey of organic grape operations in the three most important grape-producing areas in West Germany. Data on expenses for fertilizers, pesticides, machinery and buildings, on labor requirements, on the quantity and quality of yields, and on marketing channels and price premiums are compared to data on conventional grape operations from statistical sources. Based on these data, multi-period linear programming models were constructed to assess the economic implications of a transition to organic grape growing for different types of operations. Model results indicate that the grape production quota implemented in West Germany in 1989-90 favors organic methods. However, with direct marketing of wine, the effect of the quota depends on the effect that the expected rise in the price of conventional wine has on the price of organic wine. Premium prices for organically produced wine currently can be achieved only by farms that sell their wine directly to the consumer, which means that direct marketing is necessary for a profitable organic grape operation under current market conditions.