Matthijs Dekker

The nutritional significance, biosynthesis and bioavailability of glucosinolates in human foods

The glucosinolates are a large group of sulphur-containing compounds which occur in all the economically important varieties of Brassica vegetable. Their common structure comprises a β-D-thioglucose group, a sulphonated oxime moiety and a variable side-chain derived from methionine, tryptophan or phenylalanine. When the plant tissue is damaged the glucosinolates are hydrolysed by the endogenous enzyme ‘myrosinase’ (thioglucoside glycohydrolase EC 3:2:3:1), to release a range of breakdown products including the bitter, biologically active isothiocyanates. Although these compounds exert antinutritional effects in animals there is also substantial evidence that they are the principal source of anticarcinogenic activity in Brassica vegetables, and this provides a strong motive for the manipulation of glucosinolate levels in vegetables for human consumption. This review provides an overview of the evidence for a beneficial role for glucosinolates in human health, and describes the current state of knowledge regarding the genetics and biosynthesis of glucosinolates, their chemical analysis, their behaviour during cooking and processing, and their bioavailability to humans. As the genetic basis of glucosinolate biosynthesis becomes more apparent, and tools for marker-assisted plant breeding become more available, the selective breeding of horticultural brassicas with different levels and types of glucosinolates, whether by conventional means or genetic manipulation, is becoming a practical possibility. However before this strategy becomes commercially viable, the health benefits of glucosinolates for human beings must be unequivocally established. © 2000 Society of Chemical Industry

Glucosinolates in Brassica vegetables: The influence of the food supply chain on intake, bioavailability and human health

Glucosinolates (GLSs) are found in Brassica vegetables. Examples of these sources include cabbage, Brussels sprouts, broccoli, cauliflower and various root vegetables (e.g. radish and turnip). A number of epidemiological studies have identified an inverse association between consumption of these vegetables and the risk of colon and rectal cancer. Animal studies have shown changes in enzyme activities and DNA damage resulting from consumption of Brassica vegetables or isothiocyanates, the breakdown products (BDP) of GLSs in the body. Mechanistic studies have begun to identify the ways in which the compounds may exert their protective action but the relevance of these studies to protective effects in the human alimentary tract is as yet unproven. In vitro studies with a number of specific isothiocyanates have suggested mechanisms that might be the basis of their chemoprotective effects. The concentration and composition of the GLSs in different plants, but also within a plant (e.g. in the seeds, roots or leaves), can vary greatly and also changes during plant development. Furthermore, the effects of various factors in the supply chain of Brassica vegetables including breeding, cultivation, storage and processing on intake and bioavailability of GLSs are extensively discussed in this paper.

Quality function deployment in the food industry: a review

This paper presents a detailed literature review on the topic of the application of quality function deployment (QFD) in the food industry. This review is extended with a thorough description of the methodologies involved in the practice of QFD within food companies, exemplified with the help of a case study on ketchup quality improvement. The benefits, drawbacks and challenges of QFDs application in food Research and Development (R&D) are presented and discussed.

Predictive modelling of health aspects in the food production chain: a case study on glucosinolates in cabbage

Abstract In this paper, it is demonstrated that many steps in the food production chain of vegetable products can have large influence on the final intake of health protective phytochemicals. The wide variations in levels at each step in the production chain makes an experimental quantification of the dietary intake of phytochemical extremely difficult. We present a concept for predictive modelling of the effects of various processes in the production chain of vegetable products on the intake of phytochemicals with potential health benefits. This approach is intended to be used for the developments of tools to facilitate both product and process development for health products as well as epidemiological input data for bioactive substances in the diet. Protective glucosinolates present in Brassica vegetables are used to illustrate the value of such a predictive model. The described model provides a powerful tool for handling the variation of glucosinolate levels throughout the chain in a quantitative way. Product development, consumer advice and human intervention trials are important areas that could benefit enormously from this approach.

A consumer-oriented classification system for home meal replacements

Abstract This paper introduces a new definition and classification system for home meal replacements (HMR), based on convenience attributes as viewed by consumers. An overview of other food classifications, focusing on methodological aspects, is also presented. The classifying criteria chosen (shelf-life and required preparation) and their organisation in a 4×4 matrix structure demonstrated to provide a sound and effective way of classifying HMR. A qualitative analysis of HMR consumption in The Netherlands was performed by application of the developed system. Results showed that the use of a narrow range of HMR is characteristic of Dutch food consumption. The classification system is expected to provide valuable support for consumer-oriented product and process development.

Predictive modelling of migration from packaging materials into food products for regulatory purposes

Migration of low-molecular weight compounds is one of the most important problems of packaging plastics and other plastics intended to come into contact with food products. Since migration experiments are time consuming and expensive, predictive modelling has been introduced as a promising alternative. The main objective of this article is to review current knowledge on migration modelling and highlight the consequences of using modelling for regulatory purposes.

Exploring the use of consumer collages in product design

This paper presents the development, application and evaluation of a method for need identification in food product design, which combines the use of collage techniques and focus groups. Recent findings in neurobiology and psychology have considerable relevance for methodological improvement in consumer research. Based on these findings, a collage and focus group study aiming to identify feelings, emotions and experiences of consumers towards Home Meal Replacements, as well as relevant product attributes, is developed and performed. Its effectiveness is compared with that of (strictly) verbo-centric research previously carried out. Trends in image-based consumer research for product design are discussed.

Flavonoids as bioactive components in apple products.

This research focuses on determining the concentration and antioxidant activity of flavonoids in apples and apple products as a function of storage and processing. The results will be used to optimise apple products with respect to both flavonoid content and antioxidant activity.

Monitoring the Quality of Perishable Foods: Opportunities for Intelligent Packaging

This review paper discusses opportunities for intelligent packaging for monitoring directly or indirectly quality attributes of perishable packaged foods. The possible roles of intelligent packaging as a tool in supply chain management are discussed as well as the barriers to implement this kind of technology in commercial applications. Cases on pasteurized milk and fresh cod fillets illustrate the application of different intelligent packaging concepts to monitor and estimate quality attributes. Conditions influencing quality (e.g., temperature–time) can be monitored to predict the quality of perishable products when the initial quality is known and rather constant (e.g., pasteurized milk). Products with a highly variable initial quality (e.g., fresh fish) require sensors monitoring compounds correlated with quality.

A mechanistic perspective on process-induced changes in glucosinolate content in Brassica vegetables: a review.

Brassica vegetables are consumed mostly after processing, which is expected to give beneficial effects on the vegetable properties, such as improved palatability and bioavailability of nutrients, or shelf life extension. But processing also results to various changes in the content of health promoting phytochemicals like glucosinolates. This paper reviews the effects of processing on the glucosinolates content by using a mechanism approach underlying processing method employed. Cultural differences between Eastern and Western preparation practices and their possible effect on glucosinolate retention are highlighted. Boiling and blanching considerably reduce the glucosinolate content mainly due to mechanisms of cell lysis, diffusion, and leaching, and partly due to thermal and enzymatic degradation. Steaming, microwave processing, and stir frying either retain or slightly reduce the glucosinolates content due to low degrees of leaching; moreover, these methods seem to enhance extractability of glucosinolates from the plant tissue. Fermentation reduces the glucosinolate content considerably, but the underlying mechanisms are not yet studied in detail. Studying the changes of glucosinolates during processing by a mechanistic approach is shown to be valuable to understand the impact of processing and to optimize processing conditions for health benefits of these compounds.