Darryl Small

This study optimises a protocol for the estimation of α-amylase activity in a condensed starch matrix in the vicinity of the glass transition region. Enzymatic activity on the vitrified starch system was compared with that of a reference substrate, maltodextrin. The activity was assayed as the rate of release of reducing sugar using a dinitrosalicylic acid procedure. The condensed carbohydrate matrices served the dual purpose of acting as a substrate as well as producing a pronounced effect on the ability to enzymatic hydrolysis. Activation energies were estimated throughout the glass transition region of condensed carbohydrate preparations based on the concept of the spectroscopic shift factor. Results were used to demonstrate a considerable moderation by the mechanical glass transition temperature, beyond the expected linear effect of the temperature dependence, on the reaction rate of starch hydrolysis by α-amylase in comparison with the low-molecular weight chain of maltodextrin.

In the processing of a number of fresh plant tissues, the enzymes catalase and peroxidase have been measured as indicators that a sufficiently rigorous heat treatment has been applied. This has generally ensured that all other deteriorative enzymes will have been ...

... 3. Herold, A. and Lewis, DH (1977) ,dew Phytol. 79, 1. 4. Franz, G. (1973) Phytochemistry 12, 2369. 5. Baddiley, J., Blumson, NL, Di Girolamo, A. and Di Girolamo, M. (1961) Biochim. Biophys. ... and Peck, EJ, Jr. (1972) The Enzymes (Boyer, PD, ed.) 3rd edn, Vol. 6, p. 407. ...

This article reviews the applications of CE that are relevant to the analysis of small molecules in foods. CE has been applied to a wide range of important areas of food analysis and is rapidly being established as an alternative technique to chromatographic methods including HPLC and GC within analytical food and research laboratories. In recent years the analysis of food by CE has become more frequent and important and as such a variety of compounds have been separated and quantified. Although many other analytes have been detected by CE, this review will highlight areas relating primarily to the rather broad chemical classes of free amino acids, carbohydrates, organic acids, vitamins and a variety of antioxidants. In addition, information relating to the analyte, sample matrix, mode of CE employed, scope of the methodology and the detection and derivatization of the small molecules are considered and discussed.

In this study, a new system for analysis using a dual comprehensive two-dimensional gas chromatography/targeted multidimensional gas chromatography (switchable GC×GC/targeted MDGC) analysis was developed. The configuration of this system not only permits the independent operation of GC, GC×GC and targeted MDGC analyses in separate analyses, but also allows the mode to be switched from GC×GC to targeted MDGC any number

Enriched caricain was able to detoxify a major proportion of the gliadin in wholemeal wheat dough by allowing it to react for 5h at 37°C during the fermentation stage. A reduction of 82% in toxicity, as determined by the rat-liver lysosome assay, was achieved using 0.03% enzyme on weight of dough. Without enzyme, only 26% reduction occurred. The difference in reduction of toxicity achieved is statistically significant (p<0.01). The results are very similar to those obtained in our previous work using an immuno assay and the same enzyme preparation. They confirm the value of caricain as a means of reducing the toxicity of gliadin and open the way for enzyme therapy as an adjunct to the gluten free diet. This approach should lead to better control over the elimination of dietary gluten intake in conditions such as coeliac disease and dermatitis herpetiformis.

Recent studies of cereal foods have been focused upon water soluble vitamins and many of these are relatively unstable during processing. Among the conditions that are important determinants of retention are processing steps of heating as well as pH. However, it has also been shown that procedures for extraction and analysis of the vitamin require careful adaptation for particular foods as well as evaluation and validation. The purpose of the current study has been to investigate methods for measurement of vitamin E in cereal foods. The challenge is to measure up to eight vitamer forms including both tocopherol and tocotrienols and a number of HPLC methods have been compared. As alternatives to the normal phase approaches commonly used, reversed-phase systems have been trialled as a means of reducing cost and environmental issues associated with the solvents required. None of the alternative approaches have been effective and so normal phase options have been compared. Newly reporte...

INTRODUCTION Caricain is a proteolytic enzyme obtained from the papaya plant along with papain. Recent studies indicate that caricain appears to have potential to act with some specificity on the amino acid sequence that has been implicated in the problems encountered by individuals with sensitivity to gluten proteins (Cornell, et al., 2005; Cornell & Stelmasiak, 2007; Cornell et al., 2010). Therefore this may have potential application in processing designed to provide gluten-free foods for thos with coeliac disease or other sensitivities to gluten proteins. AIM The purpose here has been to study the potential of the enzyme caricain in food systems where gluten is present. MATERIALS AND METHODS Wheat dough sample preparation Doughs were prepared using strong bakers flour, salt and water as well as the crude caricain preparation (see table 1) using a small bench mixer, 3 min on slow speed and 5 min on fast. The dough was then placed in a glass beaker, covered with plastic wrap to pr...

ABSTRACT All forms of baking and processing cause a loss of nutrients, including vitamin E, but little is known about these occurrences or if they could be avoided. The objective of this research was to study the incorporation of palm oil and the stability of vitamin E in palm oil during breadmaking. Wheatmeal and rye breads were baked with and without the addition of 0, 2, 5 or 8 % palm oil. The eight E group vitamers (tocopherols and tocotrienols) were extracted using accelerated solvent extraction, freeze dried then analysed using normal phase HPLC. Compared to the controls, the inclusion of palm oil was found to increase the quantity of all forms of vitamin E in the final baked products. It is concluded that palm oil is very effective in increasing the vitamin E content of wholegrain bread.

ABSTRACT The effect of inulin addition on rheology and texture of nonfat yogurt (NFY) was studied by the large (texture analyzer) and small (dynamic oscillatory rheometry) deformation tests. Skim milks (12% solids) were supplemented with three commercial chicory inulins with different chain lengths at 4% level and inoculated with mixed cultures of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. Textural and rheological tests were conducted after an overnight storage at 4C and during a shelf life of 28 days. A good correlation was observed between the two tests. During storage, all inulin-containing yogurts in comparison with the control NFY were characterized by lower values of firmness, apparent viscosity, yield stress, complex viscosity, storage modulus and loss modulus. NFYs supplemented with long-chain inulin demonstrated a rheological behavior closer to that of control full-fat yogurt. The use of inulin and oligofructose in the food industry has grown recently because of their interesting nutritional and technological properties. In the work presented here, three commercial inulin products with different chemical composition and functions were added to yogurt milk, and changes in rheological properties of yogurt were investigated in comparison with nonsupplemented control yogurts. According to the manufacturer's specifications, Raftiline HP and Raftiline GR are suitable for fat replacement because of the presence of long-chain inulins, while Raftilose P95, being rich in mono- and disaccharides, is highly recommended for sugar replacement. The knowledge obtained from this study may be applied for the development of nonfat yogurts to satisfy the nutritional expectations of ever-increasing health conscious consumers and at the same time to match the sensory and textural characteristics of full-fat yogurt.

Cereal based foods, including Asian noodles which represent the end use of at least one-eighth of global wheat production, are potentially good sources of thiamine. However, there is a lack of data on the stability of thiamine during processing. The aim of this study was to investigate the thiamine contents of three styles of Asian noodle products: white salted, yellow

Milk concentration permeate (MCP), a low-value by-product of ultrafiltration plants and calcium carbonate-based catalysts were used for lactulose production. The results obtained show the effectiveness of oyster shell powder and limestone for lactose isomerisation as a replacement for egg shell powder. With the reaction conditions of 12mg/ml catalyst loading, reflux time of 120min at 96°C, a maximum yield of 18-21% lactulose was achievable at a cost of <50% of original lactose degradation (measured by HPLC). De-proteination of MCP by acidification prior to isomerisation helped lactulose formation in the earlier stages, but did not significantly increase the yield. The resulting lactulose MCP (40°B) incorporated at the rate of 3-4% was effective in enhancing the growth rate and acid production of Lactobacillus acidophilus (LA-5) in probiotic products.

Asian styles of noodle products represent the end-use of at least one eighth of all wheat produced globally and are potentially a good dietary source of essential nutrients. In order to investigate the factors influencing thiamin content, three styles of noodles were made under controlled laboratory conditions. The losses during preparation of dried white salted noodles were low. Boiling of

Optimal conditions for fructan precipitation from Jerusalem artichoke concentrate by adding ethanol were established by response surface methodology. The combination of the starting syrup concentration (9.9–40°B), ethanol-to-syrup (E/S) ratio (2.3:1–15.7:1) and precipitation temperature (3.1–62°C) was varied at design points of a central composite rotatable design. Significant regression models describing the changes of average chain length, fructan precipitation yield and purity value of fructans were developed with the coefficient of determination greater than 0.8. The results suggested that higher syrup concentration resulted in an increased fructan yield, but further increase in concentration had a reverse effect on average chain length and purity values. The optimum conditions for fractionating fructan composition by ethanol were estimated to be 32°B initial syrup concentration, E/S ratio of 13 and temperature of 42°C.

Proteins from Brassica sp. were prepared by alkaline extraction followed by acid precipitation. A double-enzyme (As1.398 and Flavourzyme) two-stage hydrolysis was used to hydrolyse Brassica sp. proteins, and the hydrolysates were used to generate meat-like flavourings. The effect of processing conditions on the volatile products generated from the thermal reaction between the protein hydrolysates and other additives was studied. The