Maria Papageorgiou

Classification and target compounds

Abstract Unsurprisingly, food production leads to the generation of many co-/by-products and waste material along the chain from collection through to various stages of processing and final manufacture. Such cogenerated products can pose environmental and economic problems thus reducing the profitability of the food industry. However, within the problem lies the solution, as these coproducts are rich in a variety of biomolecules of high relevance to the food and nonfood (e.g. pharmaceutical, cosmetic) industries and can command high value for the agro-food industry. In this chapter an overview is presented of some of the high added-value biomolecules identified in the different by-products generated by the most important industries (cereals, roots, tubers, pulses and oil crops, fruits, vegetables, meat, fish, and milk); the corresponding target compounds in each case as well as their potential applications in key sectors such as food, pharmaceutical, or biomedical are also outlined. The reader is guided to a number of relevant published articles for more in-depth descriptions, which are beyond the scope of this chapter.

Optimized and validated high-performance liquid chromatography method for the determination of deoxynivalenol and aflatoxins in cereals.

A simple, sensitive and accurate analytical method was optimized and developed for the determination of deoxynivalenol and aflatoxins in cereals intended for human consumption using high-performance liquid chromatography with diode array and fluorescence detection and a photochemical reactor for enhanced detection. A response surface methodology, using a fractional central composite design, was carried out for optimization of the water percentage at the beginning of the run (X1, 80-90%), the level of acetonitrile at the end of gradient system (X2, 10-20%) with the water percentage fixed at 60%, and the flow rate (X3, 0.8-1.2 mL/min). The studied responses were the chromatographic peak area, the resolution factor and the time of analysis. Optimal chromatographic conditions were: X1 = 80%, X2 = 10%, and X3 = 1 mL/min. Following a double sample extraction with water and a mixture of methanol/water, mycotoxins were rapidly purified by an optimized solid-phase extraction protocol. The optimized method was further validated with respect to linearity (R(2) >0.9991), sensitivity, precision, and recovery (90-112%). The application to 23 commercial cereal samples from Greece showed contamination levels below the legally set limits, except for one maize sample. The main advantages of the developed method are the simplicity of operation and the low cost.

HPLC-DAD-FLD Method for Simultaneous Determination of Mycotoxins in Wheat Bran

Aflatoxins, deoxynivalenol, ochratoxin A and zearalenone are the most important mycotoxins that everyone on its own, in groups or simultaneously contaminate cereals. The external layers of cereal grains (bran) apart from health promoting ingredients are also the most contaminated part with reference to mycotoxins presence. Therefore, consumption of a high fiber wheat-based diet represent an increased risk to consumers health. The objective of this study was to develop a simple and reliable high performance liquid chromatography method for the simultaneous determination of these mycotoxins in wheat bran (WB). A double extraction was applied with phosphate buffered saline/methanol and for the clean-up a multi-immunoaffinity column was utilized. The detection was carried out with diode-array and fluorescence detectors linked with a post-column photochemical reactor. After optimization of the chromatographic conditions, all mycotoxins were eluted within ~26 min. Limits of detection for each mycotoxin (0.12-12.58 µg/kg) were below the maximum levels provisioned by European Union regulations. Good linearity was observed for the analytes (r2 ≥ 0.9980). The recovery of analyzed mycotoxins ranged from 70.2 to 105.8%, with a relative standard deviation <12%. The method was successfully applied to quantify mycotoxins in 34 WB samples obtained after pearling of grains that were collected from different regions of Greece.

Introduction to cereal processing and by-products

Abstract Cereal grains have represented the principal component of the human diet for thousands of years. Their processing comprises an important part of the food production chain, but it is a complex procedure. The most common cereal processes include dry milling (wheat and rye), pearling (rice, oat, and barley), wet milling (corn and wheat), and malting (barley, corn, and wheat). During cereal processing, by-products that differ in their physical state and chemical composition are coproduced. Since cereals are an important source of carbohydrates, proteins, lipids, vitamins, mainly of B-complex and vitamin E, and inorganic and trace elements, the reutilization and valorization of their by-products is a great challenge toward the sustainable development of the agrofood sector. This chapter provides an introduction to cereal production processes and their corresponding by-products.