UK Drinking Water: A European Comparison

Introduction of the drinking-water Directive has resulted in a much more quantified approach to drinking-water quality. Increased attention from environmental groups and the media, together with occasional breaches of the limits, have resulted in a loss of confidence in the product. Infringements depend upon the stringency of the limits and the quality of available raw water. The UK is one of the few EC countries having to use a high proportion of surface water. The Directive has now been fully implemented in all member states, but information on compliance is poor. Only the UK and Ireland produce compliance reports. Published papers indicate that infringement problems exist throughout the Community, particularly for pesticides, nitrate, lead, coliforms and iron. Nevertheless, drinking water is of very high quality within the EC, and UK supplies compare very favourably with the rest.     

SHELF-LIFE EXTENSION BY PHENYLGLYOXAL OF CLOSTRIDIUM SPOROGENES-INOCULATED VACUUM-PACKAGED GROUND BEEF

Phenylglyoxal (PG), an aromatic α-dicarbonyl, is used in a variety of industrial, medical, and biological research applications. The compound delays spore germination and inhibits vegetative cells of both aerobic and anaerobic sporeforming bacteria, interacts with several critical bacterial growth factors, and is structurally similar to a number of approved food flavoring agents. Previous research demonstrated inhibitory activity against Clostridium sporogenes in model systems. Therefore, we investigated the shelf-life enhancing effectiveness of PG in C. sporogenes-inoculated vacuum-packaged ground beef at 32C. During extended incubation under temperature abuse conditions, PG delayed undesirable color changes and prevented organoleptic spoilage. Five μg PG/g inhibited proteolysis, while 156 μg PG/g delayed conversion of myoglobin to metmyoglobin, prevented H₂S production, maintained product quality and texture for 25 days, and reduced thermal resistance of C. sporogenes spores at 90C. The observed activity of PG suggests that similar activity might be found with currently approved α-dicarbonyls. Furthermore, the compound's effect on thermal resistance may serve as an example of compounds that could be used to reduce thermal processing requirements of heat-sensitive and/or minimally processed foods.     

Solubility Limit of La in the Lead Zirconate-Titanate System

The disappearing-phase method was used to determine the extent of the solid-solution region of the PLZT system for conventionally sintered ceramics prepared at 1100° and 1300°C in a PbO atmosphere provided by pbZrO₃. A decrease in the firing temperature from 1300° to 1100°C lowers the solubility limit by 5 to 8 at.% La. Beyond the limits of solubility, additional La forms La₂Zr₂O₇ and/or La₂Ti₂O₇. The limit determined by the disappearing-phase method (1300°C firing) is compared to values determined by the parametric method. The Curie temperature is stabilized at 5 at.% La for modified PbZrO₃ (1300°C firing).     

Effects of Cooking and Chemical Treatment on Heme and Nonheme Iron in Meat

Treatment of ground beef samples with heat (conventional and microwave), ascorbic acid, or H₂O₂ increased nonheme iron concentrations. The increases ranged from less than 10% to more than 100% depending on the type, length, and severity of the treatment. Cooking of fresh beef round using common household methods (braising, roasting, microwave cooking) resulted in nonheme iron increases that were generally less than 10%. Treatment of hemin and meat extract solutions with heat and H₂O₂ resulted in destruction of the iron-porphyrin complex. Oxidative cleavage of the porphyrin ring followed by release of the iron is probably the mechanism for the observed increases in nonheme iron.     

Bovine Bone Marrow Lipids

Characteristics of marrow lipids in bones from three different anatomical locations (cervical, lumbar, femur) in steers and cows on low energy (range) or high energy (feedlot) diets are reported. Cervical marrow contained the least and femur marrow the most total lipid and triglycerides (TG) were the major type of lipid present in all marrows. Phosphatidyl choline was the major PL present in all marrows. The predominant fatty acids were 16:0, 18:0 and cis 18:1. There were no consistent effects due to anatomical location of bone, diet or sex upon any of the acids measured. TG structures were similar in all marrows and the fatty acid composition of TG from steer marrow resembled that of steer intramuscular TG.     

The study of fission track and other crystalline defects using confocal scanning laser microscopy

Confocal scanning laser microscopy (SLM) is a technique that offers geologists a new way of studying structures in minerals at the submicrometre level. As an example we show how the non-destructive nature of confocal SLM can be used to measure and count fission tracks (line defects formed by the spontaneous fission of²³⁸U) in the uranium-bearing mineral apatite, and to provide information about the geometry and crystallographic orientation of fluid inclusions trapped inside apatite grains during crystallization. The technique also provides a means of studying the internal geometry of chemical zonation in minerals. The digitized nature of the SLM images makes them amenable to a variety of image analysis techniques, and we show how image analysis can be used to measure fission tracks in mica sheets and provide crude estimates of track dip. Finally, using a chemically etched mica sheet we show how confocal SLM can be used to provide a detailed near-surface (1–5 μm) analysis of geological materials.     

Proximate Analysis of Cooked Chuck and Round Roasts from Two Beef Breed-Types on Two Feeding Regimes

Cooked roast samples from two beef breed-types and from two feeding regimes were assayed for proximate composition. Three muscle roasts from the round primal cut (semimembranosus, SM; semitendinosus, ST; biceps femoris, BF) were similar to each other in composition. Roasts from chuck primal cut (shoulder clod roasts) differed considerably in composition from round roasts: clod roasts were higher in fat and lower in moisture, protein and ash. Breed-type had minimal effect on proximate composition, but feeding regime did significantly affect composition. Beef fed a higher energy regime produced roasted meat which was higher in fat and lower in moisture content.     

National In-Home Consumer Evaluation of Pork Roasts From Pigs Administered Porcine Somatotropin (pSt)

Boneless pork loin (longissimus) or ham (semimembranosus) roasts from 60 control and 60 porcine somatotropin-produced (pSt) pigs (3 mg daily) were analyzed for composition and evaluated by 120 families in each of three major cities. In San Antonio and Portland each family received a loin roast from a control pig and a pSt-treated pig. In Buffalo, each family received a fresh ham roast from a control pig and a pSt-treated pig. Consumers were asked to evaluate the roasts during conventional in-home meal preparation and consumption. Overall, pSt roasts contained less intramuscular fat and no differences were noted in acceptability scores when control loin or ham roasts were compared with pSt-produced loin or ham roasts. No differences were noted in the preference scores for the loin roasts; however, consumers preferred the tenderness, juiciness and flavor of the control ham roasts.     

EXTRACT RELEASE VOLUME (ERV) RESPONSES WITH ASEPTIC AND INOCULATED PORK

SUMMARY– The extract-release volume (ERV) phenomenon, previously reported as a reliable rapid indicator of bacterial spoilage in meat, was observed for pork muscle obtained aseptically and for that inoculated with pure and mixed cultures of bacteria over a 20-day storage period at 2° and 10°C. ERV values obtained using pork longissimus dorsi muscle were found to be inversely related to bacterial numbers regardless of population type (homogeneous or heterogeneous) of the microorganisms. The correlations between ERV and bacterial numbers did not denote reliable prediction of the bacteriological quality of pork by ERV. Under conditions of mixed culture sample contamination the correlation between ERV and bacterial numbers was much higher than for pure culture sample contamination with psychrophilic, anaerobic, or acid-producing bacteria. Minor initial differences in ERV between control (aseptic) and inoculated samples indicated that ERV responded to growth of the bacteria rather than to their presence per se. Differences in ERV that were attributable to sample source (animal differences) by analysis of variance test indicated there was a wide range of hydration capacities in pork longissimus dorsi muscle samples. This disparity minimized the significance of the influence of bacterial growth on the ERV response for practical applications. Contrary to the usual ERV response observed with meat spoiled under refrigerator conditions, ERV was found to increase with storage time and bacterial growth when pork was contaminated with a putrefactive anaerobe (Clostridium perfringens) and stored at 35°C. Though pH appeared to influence the magnitude of the changes observed in ERV, decreases in ERV with bacterial growth or storage time could not be explained solely as a pH effect.     

Vitamin Retention, Color and Texture in Thermally Processed Green Beans and Royal Ann Cherries Packed in Pouches and Cans

Thiamin (B-1) ascorbic acid (AA) and vitamin B-6 (B-6) were determined in pouched and canned green beans immediately after processing and after storage at 24–26°C or 38°C. AA and B-6 were also determined in pouched and canned cherries before and after storage at 24–26°C. There was significantly more B-1 and AA in drained pouched green beans, and more AA in drained pouched cherries than in canned ones. B-6 values in the solids of the pouched and canned products were not significantly different. These three vitamins were significantly reduced in drained pouched and canned green beans after storage at 38°C. B-6 was significantly reduced in the stored cherries. Compared to canned, the pouched products were brighter and firmer in texture.