Nicolaas Busscher

Organic food quality: a framework for concept, definition and evaluation from the European perspective.

Consumers buy organic food because they believe in the high quality of the product. Furthermore, the EU legal regulatory framework for organic food and farming defines high quality of the products as an important goal of production. A major challenge is the need to define food quality concepts and methods for determination. A background is described which allows embedding of the quality definitions as well as evaluation methods into a conceptual framework connected to the vision and mission of organic agriculture and food production. Organic food quality is defined through specific aspects and criteria. For evaluation each criterion has to be described by indicators. The determination of indicators should be through parameters, where parameters are described by methods. Conversely, the conceptual framework is described according to underlying principles and starting definitions are given, but further work has do be done on the detailed scientific description of the indicators. Furthermore, parameters have to be defined for the evaluation of suitability of these indicators for organic food production.

Standardization of the Biocrystallization Method for Carrot Samples

ABSTRACT The growing organic market demands methods which can describe food quality within the organic system (authentication). Several studies indicate that methods, such as the biocrystallization method, are suitable for this question. More or less reproducible crystallization patterns emerge when an aqueous dihydrate cupric chloride solution with plant extract is crystallized on a glass dish. The emerging patterns are characteristic of sample material. To be applied in routine analysis for example for authentication of organic products, the biocrystallization method has to be standardized. After the laboratory process was documented and a computerized pattern evaluation tool was further developed and applied, the method was standardized for selected carrot samples, which is described here. For standardization, several factors of influence were tested and the reproducibility between three different laboratories in the EU was investigated. The method is able to differentiate patterns from samples from different farming treatments and processing steps as statistically significant. This represents a significant step forward beyond the state of the art.

Standardization and validation of the visual evaluation of biocrystallizations.

ABSTRACT The biocrystallization method has been used as a holistic method for evaluating food samples since the 1930s and has, as recent reviews have concluded, been successful in discriminating farming systems in several studies. However, it is noted that a standardization and validation for more objective means of evaluation of biocrystallization pictures and a clearly defined and communicable language, as well as possibilities for verification, are still lacking. During the years 2002–2006 a project for standardizing and validating the visual evaluation of these biocrystallizations took place, performed by a group consisting of three European research institutes. As no pre-set methodology nor norms for the visual evaluation existed, the choice was made to work according to existing norms on sensory analysis and to adapt these to the visual evaluation. The main norm, ISO-Norm 11035, for establishing sensory profiles was adapted towards these pictures. A panel was formed, mainly morphological descriptors were selected and defined, a scale with references was established, the panel trained and tested for pictures, produced on the basis of carrots of different qualities. Reliability and validity aspects of the panel, as well as the structure of the set of criteria were evaluated. According to standard rates for diverse statistical tests the panel has been validated for the evaluation of carrots with a defined set of descriptors. The set of descriptors contains sub-domains which can be used for further development of the evaluation method, towards a more integrated, holistic ‘Gestalt’-evaluation, and towards finally interpretation of these pictures. The followed process and results are unique in connection to this method.

Evaporation influences on the crystallization of an aqueous dihydrate cupric chloride solution with additives

The overall structure of the crystallization results of dihydrate cupric chloride with additives in a petri dish is affected by the duration between the beginning of the evaporation and the start of the crystallization. Experiments done with polyvinylpyrrolidone and freeze-dried carrot as additive are compared with those of the additive free case. The dependency of dewetting on the dihydrate cupric chloride amount is discussed in terms of depletion of the solution and the surface tension properties of the system. The possible influence of the depletion is depending on the moment the crystallization starts. This is defined by the size of the evaporated area on the dish.

Quality assessment of baby food made of different pre-processed organic raw materials under industrial processing conditions

The market for processed food is rapidly growing. The industry needs methods for “processing with care” leading to high quality products in order to meet consumers’ expectations. Processing influences the quality of the finished product through various factors. In carrot baby food, these are the raw material, the pre-processing and storage treatments as well as the processing conditions. In this study, a quality assessment was performed on baby food made from different pre-processed raw materials. The experiments were carried out under industrial conditions using fresh, frozen and stored organic carrots as raw material. Statistically significant differences were found for sensory attributes among the three autoclaved puree samples (e.g. overall odour F = 90.72, p < 0.001). Samples processed from frozen carrots show increased moisture content and decrease of several chemical constituents. Biocrystallization identified changes between replications of the cooking. Pre-treatment of raw material has a significant influence on the final quality of the baby food.

Questions on the Validation of Holistic Methods of Testing Organic Food Quality

ABSTRACT The regulation of organic production and processing focuses on process-related quality concepts rather than product oriented quality management. Therefore no standards exist that define the product oriented quality aspects of organic food. Methods such as the biocrystallization method seem to be able to classify organic products. Methods that are applied must reflect the history of the sample in growth and processing. These methods can be applied either for authentication or in relation to technical aspects (storage, processing steps) as well as human health. Each quality determination needs a question which will be answered from the laboratory method. The question needs to be specific enough and the method needs validation. Validation means testing if the method can answer the question or not. The process of validation is defined for analytical methods (single compound determination) in international norms such as the ISO 17025 for testing laboratories. The article describes how validation procedures can be applied to biocrystallization methods for quality tests of organic products.

Multi-method comparison of carrot quality from a conventional and three organic cropping systems with increasing levels of nutrient recycling

BACKGROUND There is a need to advance the study of the effects of organic and conventional systems on product quality. In particular, little is known about the importance of different farming practices concerning nutrient cycling and the use of external inputs within organic farming for the quality characteristics of the products. In this study the quality characteristics of carrot grown under different farming practices (conventional and three organic cropping systems) over a two-year period were analysed with the aim of discriminating between organic and conventional and investigating the effect of different organic farming practices concerning nutrient recycling and use of external nutrient input. RESULTS All quality characteristics measured did not give a clear differentiation between the carrots from the different growing systems, even when multivariate statistical evaluation (principal component analysis) was applied, because of the significance of the differences between the field replicates within each management system and of the seasonality. Only some tendencies were emphasised over the two years that could be related to the fertilisation practices and the external inputs used. CONCLUSION The results indicated that it was not possible to discriminate over the years between carrots from conventional and different organic cropping systems even though controlled conditions and a multi-method approach of analysis were adopted.

Status quo and future research challenges on organic food quality determination with focus on laboratory methods

Organic food quality determination needs multi-dimensional evaluation tools. The main focus is on the authentication as an analytical verification of the certification process. New fingerprinting approaches such as ultra-performance liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, direct analysis in real time-high-resolution mass spectrometry as well as crystallization with and without the presence of additives seem to be promising methods in terms of time of analysis and detecting organic system-related parameters. For further methodological development, a system approach is recommended, which also takes into account food structure aspects. Furthermore, the authentication of processed organic samples needs more consciousness, hence most of organic food is complex and processed.

Development and Performance of Crystallization with Additives Applied on Different Milk Samples

Crystallization with additives is developed on milk samples from different processing treatments. Performance tests are carried out based on structure analysis of the crystallization patterns. Crystallization with milk as additive is applied following changes in milk after different processing treatments. When an aqueous cupric chloride dihydrate solution crystallizes in the presence of milk as additive, specific patterns emerge, which can be evaluated by image analysis. Milk samples were heated and homogenized in a pilot plant and characterized by various parameters. Furthermore, milk samples from the market were tested. Patterns from milk after heat treatment and homogenization are significantly different from those derived from untreated milk. The experiments could be reproduced for other milk samples, on different days and in another laboratory.

Differentiation of organic and non-organic winter wheat cultivars from a controlled field trial by crystallization patterns

BACKGROUND There is a need for authentication tools in order to verify the existing certification system. Recently, markers for analytical authentication of organic products were evaluated. Herein, crystallization with additives was described as an interesting fingerprint approach which needs further evidence, based on a standardized method and well-documented sample origin. RESULTS The fingerprint of wheat cultivars from a controlled field trial is generated from structure analysis variables of crystal patterns. Method performance was tested on factors such as crystallization chamber, day of experiment and region of interest of the patterns. Two different organic treatments and two different treatments of the non-organic regime can be grouped together in each of three consecutive seasons. When the k-nearest-neighbor classification method was applied, approximately 84% of Runal samples and 95% of Titlis samples were classified correctly into organic and non-organic origin using cross-validation. CONCLUSION Crystallization with additive offers an interesting complementary fingerprint method for organic wheat samples. When the method is applied to winter wheat from the DOK trial, organic and non-organic treated samples can be differentiated significantly based on pattern recognition. Therefore crystallization with additives seems to be a promising tool in organic wheat authentication.