Effect of pectinolytic juice production on the extractability and fate of bilberry and black currant anthocyanins

Bilberries (Vaccinium myrtillus L.) and black currants (Ribes nigrum L.), dark blue berries rich in anthocyanins, were processed with an aid of commercial pectinolytic enzyme preparations, and the effect of processing on berry anthocyanins was investigated. The enzyme preparations were dosed based on their polygalacturonase activity from 1 to 100 nkat/g of berry mash. The juice yields were determined by weighing, and anthocyanin analyses were performed with HPLC. The bilberry and black currant juice yields increased significantly in enzyme-aided treatments with comparison to control, even with the lowest (1 nkat/g) polygalacturonase dosage. The anthocyanin yield increased by up to 83% for bilberries and up to 58% for black currants in enzyme-aided treatments as compared to control. The results showed that higher polygalacturonase dosage was needed for black currant to achieve the maximal juice and anthocyanin yields than for bilberries. The stability and the profile of extracted anthocyanins were greatly affected by the glycosidase side activities present in the enzyme preparations, which were able to hydrolyze certain anthocyanins to the corresponding aglycones. In addition, the data indicate that anthocyanidin rutinosides were more easily extracted than those of glucosides, which prevailed over the arabinosides and galactosides. Thus, prior to processing it is important to know the intact anthocyanin structures of the raw material, and the activity profile of the enzyme preparation to obtain optimal anthocyanin extractability and enzyme dosage.     

Removal of metals and anions from drinking water by ion exchange

Five organic and two inorganic ion exchangers were evaluated for the removal of metals and anions from water of two drilled wells. Sodium titanate (CoTreat) and a chelating aminophosphonate resin were the most efficient exchangers in removing transition metals from the total of 1800 bed volumes processed. CoTreat was the best for almost all of the transition metals. The breakthrough level of manganese was below 1% with CoTreat even when its concentration in the feed water was high (1 mg/l). The weak acid cation resin took up transition metals relatively efficiently. Somewhat unexpectedly, the cation exchangers also removed arsenic from water. Arsenic may have been sorbed on iron species, which again was adsorbed and filtered by the exchanger beds. Most of the cation exchangers took up calcium and magnesium at low processing capacities (<400 BV), and the strong base anion resin took up nitrate, bromide and sulphate very efficiently below 700 bed volumes. Neither chloride nor fluoride was taken up by the exchangers tested.     

Sugars, sugar alcohols, fruit acids, and ascorbic acid in wild Chinese sea buckthorn (Hippophaë rhamnoides ssp. sinensis) with special reference to influence of latitude and altitude

Wild berries of Hippophaë rhamnoides ssp. sinensis were collected from nine natural growth sites in China in three consecutive years in order to get an overall profile of the sugars, sugar alcohols, fruit acids, and ascorbic acid, and especially of the influence of the latitude and altitude of the growth place on these components. The contents of fructose, glucose, and l-quebrachitol in the berry juice varied in the ranges of 0.01-7.17, 0.05-7.85 and 0.21-1.09 g/100 mL, respectively, those of malic, quinic, and ascorbic acids were 1.55-8.84, 0.07-2.94, and 0.25-1.66 g/100 mL, respectively. The berries from Hebei and Inner Mongolia were characterized by high contents of sugars and l-quebrachitol and low contents of malic acid and ascorbic acid. In contrast, the berries from Sichuan and Qinghai contained lower contents of sugars and higher contents of malic acid and ascorbic acid than the berries from other growth areas. The berries from Sichuan differed considerably from others by the remarkably low contents of sugars and the exceptionally high contents of acids. The contents of fructose, glucose, and total sugar decreased as the altitude increased and as the latitude decreased (p < 0.05). In contrast, the contents of malic acid and ascorbic acid increased as the altitude increased and as the latitude decreased (p < 0.05). The contents of quinic acid and l-quebrachitol correlated strongly and positively with the latitude (p < 0.01).     

Gravure printed organic rectifying diodes operating at high frequencies

Organic rectifier diodes operating at 10 MHz made using roll-to-roll compatible mass printing processes to define patterns and deposit inks are reported. The diodes consist of a layer of poly(triarylamine) sandwiched between layers of silver and copper. No high resolution prepatterning of any surfaces was performed, thus the entire process could be carried out on large-scale roll-to-roll production lines. The organic diode based rectifier circuit generates a DC output voltage of approximately 2.7 V at 10 MHz, using an input signal with zero-to-peak voltage amplitude of 10 V. The result demonstrates the possibility of printed organic diodes for RFID applications.     

Sourdough and cereal fermentation in a nutritional perspective

Use of sourdough is of expanding interest for improvement of flavour, structure and stability of baked goods. Cereal fermentations also show significant potential in improvement and design of the nutritional quality and health effects of foods and ingredients. In addition to improving the sensory quality of whole grain, fibre-rich or gluten-free products, sourdough can also actively retard starch digestibility leading to low glycemic responses, modulate levels and bioaccessibility of bioactive compounds, and improve mineral bioavailability. Cereal fermentation may produce non-digestible polysaccharides, or modify accessibility of the grain fibre complex to gut microbiota. It has also been suggested that degradation of gluten may render bread better suitable for celiac persons.The changes in cereal matrix potentially leading to improved nutritional quality are numerous. They include acid production, suggested to retard starch digestibility, and to adjust pH to a range which favours the action of certain endogenous enzymes, thus changing the bioavailability pattern of minerals and phytochemicals. This is especially beneficial in products rich in bran to deliver minerals and potentially protective compounds in the blood circulation. The action of enzymes during fermentation also causes hydrolysis and solubilisation of grain macromolecules, such as proteins and cell wall polysaccharides. This changes product texture, which may affect nutrient and non-nutrient absorption. New bioactive compounds, such as prebiotic oligosaccharides or other metabolites, may also be formed in cereal fermentations.     

On scalarizing functions in multiobjective optimization

Scalarizing functions play an essential role in solving multiobjective optimization problems. Many different scalarizing functions have been suggested in the literature based on different approaches. Here we concentrate on classification and reference point-based functions. We present a collection of functions that have been used in interactive methods as well as some modifications. We compare their theoretical properties and numerical behaviour. In particular, we are interested in the relation between the information provided and the results obtained. Our aim is to select some of them to be used in our WWW-NIMBUS optimization system. Received: June 11, 2001 / Accepted: October 31, 2001     

Evolution towards smart home environments: empirical evaluation of three user interfaces

Smart home environments have evolved to the point where everyday objects and devices at home can be networked to give the inhabitants new means to control them. Familiar information appliances can be used as user interfaces (UIs) to home functions to achieve a more convenient user experience. This paper reports an ethnographic study of smart home usability and living experience. The purpose of the research was to evaluate three UIs—a PC, a media terminal, and a mobile phone—for smart home environments. The results show two main types of activity patterns, pattern control and instant control, which require different UI solutions. The results suggest that a PC can act as a central unit to control functions for activity patterns that can be planned and determined in advance. The mobile phone, on the other hand, is well suited for instant control. The mobile phone turned out to be the primary and most frequently used UI during the 6-month trial period in the smart apartment.     

Best compromise solution for a new multiobjective scheduling problem

In future wireless networks, a mobile terminal will be able to communicate with a service provider using several network connections. These connections to networks will have different properties and they will be priced separately. In order to minimize the total communication time and the total transmission costs, an automatic method for selecting the network connections is needed. Here, we describe the network connection selection problem and formulate it mathematically. We discuss solving the problem and analyse different multiobjective optimization approaches for it.