VARIATION IN pH AND LACTATE LEVELS IN MALTS

Malt pH, defined as the pH of worts prepared by the Institute of Brewing Methods of Analysis, was examined in commercial malts from a single malting plant over four crop years, 1990 to 1993. Batch to batch variability was found, in addition to a distinct pattern within two of the years, with a gradual decrease in the winter months following commencement of malting of the new crop barley, followed by a subsequent increase in the late summer. Variability in pH and the longer term trend were not related to any measured processing variables or characteristics of the barley used for malting. Possible reasons for the differences in pH were examined and a negative relationship between malt pH and wort lactate content was demonstrated in a selection of malts from two crop years. A method is proposed for extraction and purification of lactate directly from malt and using this method it was shown that lactate in wort derives mainly from malt with only small amounts being produced during mashing.     

AFLATOXIGENIC ASPERGILLI IN FOODS AND FEEDS IN UGANDA

Studies conducted during the sixties and the seventies on food crops in Uganda showed that the populace was exposed to consumption of aflatoxin-contaminated foods. These studies also linked the highest incidence of liver cancer in the world to the presence of high levels of aflatoxins in the food and beverages. After a lapse of a decade, it was of interest to investigate the occurrence of aflatoxins and aflatoxigenic fungi in staple Ugandan food crops and poultry feeds derived from these foodstuffs. A simple, rapid and reproducible procedure was used. The procedure consisted of growing or culturing feed grains on a selective medium, Aspergillus flavus/parasiticus agar (AFPA) followed by screening for aflatoxin producing fungi on a coconut agar medium (CAM) under UV light with a subsequent confirmatory screening method for aflatoxin production by the fungi in pure culture. Fifty-four samples consisting of corn and peanuts, soybean and poultry feed were analyzed for content of aflatoxigenic. A. flavus/parasiticus and 25 of the samples were also screened for aflatoxins B₁ and G₁, zearalenone, sterigmatocystin, ochratoxin A, citrinin, vomitoxin, and diacetoxyscirpenol (DAS). Aflatoxigenic A. flavus/parasiticus was detected from the majority of corn (77%), peanuts (36% human food and 83.3% animal feed) and poultry feed (66.6%). but not from soybean samples. Two samples out of 25 contained detectable levels of aJatosin B, (20 ppb). For the jirst time other mycotoxins, zearalenone (3 samples) and vomitoxin (2 samples) were detected in corn from Uganda.     

METHOD TO INVESTIGATE DIFFERENCES IN CHEWING BEHAVIOUR IN HUMANS

This study examines whether the patterns of muscle activity measured from the masticatory muscles during a chew are sufficiently reproducible to form the basis of a characterisation of chewing behaviour, and whether they express the degree of variation evident between individuals. Electromyograph (EMG) readings of the repetitive activity involved in chewing gum were analyzed for 10 subjects, each on three separate occasions. For each individual the temporal aspects of the chew cycle (duration of the activity burst, period between bursts of activity and duration of the complete cycle) were reproducible between EMG recording sessions. Consistency was also found for amplitude aspects of the EMG record: mean voltage within the activity burst, maximum voltage, and the area under the EMG trace. For all six parameters there was significant variation between subjects. The study showed that variations in the chewing pattern, as occur for chewing on opposite sides of the mouth, were reflected in the 6 EMG parameters examined, and that the changes elicited were different for each individual. Moreover, encouraging subjects to concentrate on the act of chewing caused them to modify their chewing pattern, highlighting the importance of avoiding such attention when assessing habitual chewing behaviour.     

CRACKING IN POTATOES

Cracking in two varieties of potatoes was investigated by compressing whole tubers between flat plates at low compression rates. It was found that resulting crack areas correlated directly with the energy stored at cracking. Of the energy imparted to the tuber, a large proportion is dissipated during compression.
Cracking occurs when the stored energy exceeds a critical value, approximately 1.6 J for Sebago and 0.9 J for Pontiac. The extent of cracking is determined by the fracture toughness, calculated to be 1350 Jm⁻² for Sebago and 1230 Jm⁻² for Pontiac. The Sebago variety is thus more resistant to cracking than Pontiac. The energy dissipative mechanisms in hysteresis and crack propagation are explained in terms of the structure of potato tissue.     

DEVELOPMENTS IN THE COMMON AGRICULTURAL POLICY IN THE DAIRY SECTOR

The development of the Common Agricultural Policy in relation to the dairy sector and its progress since 1968 are discussed, showing the intricacies of the pricing policy and the need for stabilization of the markets. Export of dairy produce with the various schemes adopted to enlarge the market, general consumer subsidies, and structural measures are described. The difficulties implicated in the skim milk surplus in major dairying countries and the limited markets are examined, world problems in the dairy sector are outlined and the need for a sound and constructive policy emphasized. The paper also stresses the importance of finding solutions for effective use of resources. ( Editor's summary )     

鞣制材料及成品革中甲醛的研究

甲醛通常是用于合成鞣剂制备的一种基本原材料。即使目前的工业生产过程采用电脑进行控制,但也可能在最终产品中含有甲醛。甲醛是一种对于人体或其他生物极具危害性的物质。因此,在一些强制性条文中明确规定了这种物质在成品革中的最大含量以及测定其存在所应参照的分析方法。然而皮革中甲醛含量的测定方法不能完全适用于鞣剂产品中甲醛含量的测定,实际上会有很多因其他物质的存在而产生的干扰因素。所以不可能把鞣剂材料中甲醛含量和成品革的甲醛含量之间进行比较。论文对以上这些因素的数据进行了研究,旨在降低鞣剂产品及其所生产皮革中的甲醛含量。     

CHANGES IN SUGARS AND LYSINE IN BABY FOODS DURING STORAGE

The effect of storage on sugar content (fructose, glucose, sucrose) and free lysine in vegetable, meat, fish and fruit baby foods for a period of two years and at temperatures of 5, 15 and 25C were studied. The results showed that under these storage conditions a decrease occurred in fructose, glucose and sucrose for vegetable, meat and fish foods. A drop in sucrose was found in the fruit sample, together with an increase in fructose and glucose. The increase of reducing sugars in this sample is attributed to the hydrolysis of sucrose, an effect which is favorable because of storage temperature. A drop in free lysine was found for the four types of samples; this decrease was dependent on storage temperature but mainly on the time of storage. After one year, the levels of lysine were decreased by half or more at all temperatures. Although infants can get lysine from other sources such as milk and cereals, the lysine loss can be important leading to negative nutritional consequences if infants mainly eat baby foods stored at least for one year. The loss of reducing sugars and of lysine showed that during storage of these products a Maillard browning reaction between reducing sugar and lysine occurred.     

OCCURRENCE OF AFLATOXINS IN VARIOUS NUTS COMMERCIALIZED IN TURKEY

Nuts are important agricultural commodities in Turkey as they are exported and largely consumed domestically. Two hundred and seventeen samples of hazelnuts, pistachio nuts and peanuts were randomly collected from public markets, bazaars, supermarkets and retail stores in several regions of Turkey and analyzed for the incidence of aflatoxin (B1, B2, G1, G2) contamination by high-performance liquid chromatography. The levels of aflatoxin B1 (AFB1) and the total aflatoxins in the majority of samples analyzed (87.09%) were so low that they were not quantifiable. Thirty-one samples (14.28%) were found to have low levels of aflatoxins, below the Turkish National regulatory limits of 5 µg/kg for AFB1 and 10 µg/kg for total aflatoxins. However, four samples (1.84%) showed a level of contamination that exceeded the maximum tolerated levels set in the Turkish regulations. The highest value of AFB1 was 36.81 µg/kg in pistachio nuts. This article reports the data of the first survey on the presence of aflatoxins in nuts sampled in three distinct regions of Turkey.

PRACTICAL APPLICATIONS

The formation of aflatoxins depends not only on the genetic potential of mold strains but also on environmental factors, especially during post-harvest transportation and storage. Although further national surveys must be performed on a regular base, the results of the present study indicate a reduced level of aflatoxin contamination of nut-based products compared to earlier observations. The results conclude that implementation of stricter quality control measures, technical assistance to private sector actors and regulatory initiatives to support employment of these strategies undertaken in recent years by the National Authorities have paid back.     

甲壳素和壳聚糖在食品工业中应用的新进展

甲壳素和壳聚糖在食品工业中的应用非常广泛。对甲壳素或壳聚糖用于抗菌剂；免疫增强剂；减肥／降脂、降血压以及保护肠道功能剂；液体食品的澄清剂、果蔬保鲜剂、食用包装膜；食品废水处理、饮用水净化剂；食品加工剂、肉制品抗氧化剂；固定化酶载体以及霉菌污染检测等方面的应用进行了综述。     

MODERN MILK PRODUCTION METHODS IN THE EEC - IN SCOTLAND

The future of the farming industry in Scotland as planned in the Government White Paper, and the significance of the part played by milk production is discussed. Comparisons between average herd sizes in the EEC and those of Scotland, the North of Scotland and Morayshire are given and methods of milking and feeding shown. The need for better grass, better management and building, also the importance of simple record keeping is stressed (Editor's summary).     

HEAT INDUCED CHANGES IN THIOL GROUPS IN SQUID PROTEINS

Changes in the thiol groups were determined in the mantle meat of the squid (Illex argentinus) after heating at 98°C for 45 min. The contents of -SH groups in the raw mince was about 90 μmoles/g protein and after heating decreased by about 30%. The total contents of -SH groups after reduction of disulfide bridges by NaBH₄ was 120 μmoles/g protein in the raw sample and did not change significantly in the cooked meat. After 45 min of cooking the mince contained about 18 times more dimethylamine and only twice as much free formaldehyde as the raw samples. The correlation coefficients between free -SH groups contents and the solubility, degree of thermal coagulation of proteins as well as the water holding capacity of the meat were +0.936, -0.947, and +0.880, respectively.     

CONTAMINATION OF PATULIN IN CLEAR APPLE JUICE IN MASHHAD, IRAN

Patulin is a frequent contaminant of moldy and rotten apples and apple products. The aim of this study was to evaluate patulin contamination in 58 apple juices collected from a retail market in Mashhad during winter and spring of 2006.
Samples were assayed for patulin by high-performance liquid chromatography. Fifty-four samples were positive for patulin at levels that ranged from 10.5 to 121.8 µg/L, and six samples had patulin levels higher than 50 µg/L. The overall mean of patulin concentration was 29.2  ±  19.5 µg/L. Forty-eight samples had patulin concentration between 5 and 50 µg/L. Although the mean concentration of patulin samples was lower than Iranian maximum tolerated level of 50 µg/L, contamination of 10% of the samples at levels higher than 50 µg/L indicated the need for improving production techniques by the industry.

PRACTICAL APPLICATIONS

Studies have shown that the concentration of patulin may exceed the determined limits in apple juice and in other fruit products. Its presence can be a potential threat to the health of consumers, particularly children. The results may help us in understanding what should be the level of patulin in apple juice. The awareness of the apple industry of patulin contamination in fruit and the implementation of improved techniques for the production of apple products with reduced patulin concentrations have contributed to the quality of apple juice that are available on the Iranian market.     

DEVELOPMENTS IN THE MALTING AND BREWING INDUSTRIES IN GERMANY*

Changes in the methods of malting and brewing which have been introduced into the industry in Germany are reviewed. In general, these changes have allowed economy in malting time and in time required for fermentation and maturation, without having any deleterious effect on beer quality. Mashing, by the decoction system, and wort boiling have not altered greatly though closed cooling systems are now more general. All these modifications of procedure have to be geared not only to the changing drinking habits of the public but also to the need to supply a wide range of different products.     

SEASONAL VARIATIONS IN FATTY ACID COMPOSITION OF OIL IN DEVELOPING COCONUT

ABSTRACT

Studies on seasonal variation in oil and fatty acid profile of developing solid endosperm of two cultivars, West Coast Tall (WCT) and Chowghat Orange Dwarf (COD), and their hybrids indicated that oil percentage increased from 30% in 6‐month‐old nuts to 63% in matured nuts (12 months old). Nuts sampled during July from different levels of maturity had high oil percentage and followed by those sampled during April, October and January. During nut development to maturity, the percentages and contents of medium and long chain saturated fatty acids increased except that of palmitic and myristic acids. Concentration of long chain unsaturated fatty acids (LCUFAs) in developing coconut kernel were high at 5 and 6 months after fertilization and then decreased toward maturity. The LCUFAs were high in nuts developing during October; consequently, saturated to unsaturated fatty acid ratios were low during October. Results indicated that nuts matured during October had better nutritional quality for human consumption and those matured during January are more suitable for industrial purpose due to higher medium chain fatty acid concentrations.

PRACTICAL APPLICATIONS

Coconut is consumed either as the tender nut (5–6 months after fertilization) or as the kernel from mature nut (12 months after fertilization). Recent technologies of making snowball tender nut use the nuts aged 7–8 months old. Kernel also is consumed in this product. Apart from this, the coconut is being increasingly used for making different kernel‐based value‐added products. This information is useful, as the value‐added products are being developed using different maturities of coconut. Hence, it is of paramount importance that the fatty acid profile of coconut kernel is known in detail for assessing the safety of food consumption from the human health point of view. Apart from this, information on the seasonal variation in fatty acid profile of developing endosperm gives an integrated knowledge so as to optimize the usage of coconut kernel for both human consumption and industrial exploitation.

     

QUALITY CHANGES IN ORGANIC TOMATOES PACKAGED IN BIODEGRADABLE PLASTIC FILMS

Quality changes in organic tomatoes stored in four biodegradable packages and in LDPE‐bags at 11 ± 1C and 75–85% RH were studied for three weeks. Organic tomatoes were packed in perforated LDPE‐bags and the following biodegradable packages: a perforated Mater‐Bi®‐bag, a Biopol®‐coated paperboard tray overwrapped with a perforated Mater‐Bi®‐bag, a polylactide coated paperboard tray overwrapped with a perforated Mater‐Bi®‐bag, and a perforated cellophane bag. The tomatoes were analyzed for weight loss, moisture content, color, firmness and flavor. Package type had no significant influence on the tomatoes' sensory quality, whereas storage time significantly (p < 0.05) influenced the fruits' color, flavor and firmness. The tomatoes' firmness decreased, their redness (a*value) increased and their flavor diminished during storage. The tomatoes lost more of their weight in biodegradable packages than in LDPE packages.     

柚、柑桔副产物利用的研究进展

柚子、柑桔的副产物包括果皮、种子等，富含多种功能成分，具有重要的开发价值。阐述了柚子及柑桔副产物中主要功能性成分的提取方法及其生物活性和药理特性，综述了国内外对它们开发利用的研究进展，旨在为柚子及柑桔副产物综合利用提供参考依据。     

COMBINED EFFECTS IN PREVENTING ENZYMATIC BROWNING REACTIONS IN MINIMALLY PROCESSED FRUIT

Fresh sliced apples were dipped in ethanol or cysteine solutions and/or packaged in air or modified atmosphere in order to retard oxidative browning. Modified atmosphere packaging was effective in inhibiting darkening for at least nine days at refrigerated storage conditions. The combination ethanol dip/modified atmosphere packaging resulted as a suitable method in maintaining the original color in apple slices even after exposure to air.     

LIPIDS IN WORT

Material balances have been constructed for lipids during wort preparation in commercial breweries. 4–5% of malt lipids were released into the wort using the mash filter, 1·0% with the lauter tun but only 0–3% with the mash tun. Up to 30% of malt lipids may be oxidised during mashing. Hop products make a contribution to the lipids in the copper though these lipids are not readily extracted. Efficient removal of spent hops and hot break will ensure a low level of wort lipids in the fermentation vessel.     

IN MILK BOTTLES

Visual inspection of milk bottles with the current labour problems and costs, has shown the need for an effective and economical method of inspection and the role of modern electronics in its development is discussed. Various types of the latest inspection machines are considered, showing the transition from the vacuum tube to the transistor and the development during the last few years of integrated circuit technology. The impact on many industries as well as on the dairy industry, with the complex logical operations now possible is stressed.