The aim of this study was to examine the contribution of sugar, organic acid, neutral phenol, and anthocyanin fractions and added ascorbic acid to grape and pomegranate-nectarine juice total phenol, ORAC, FRAP, and DPPH values. Neutral phenol and anthocyanin fractions contributed ≥75% of the total antioxidant capacity (TAC) for both juices. Intrinsic synergy and antagonism among the fractionated constituents occurred inconsistently in each assay. Sugars and organic acids antagonized pomegranate juice neutral phenols and anthocyanins in the DPPH assay by 50% and the grape juice ORAC value by 21%, but were synergistic to the grape juice FRAP value. The added ascorbic acid was dose-dependently synergistic with pomegranate and grape juice total phenol, DPPH, and FRAP assays, but less so in the ORAC assay. Thus, the interactions between grape and pomegranate juice constituents determine TAC and total phenol values, and synergy in these assays could not be attributed solely to polyphenols.
The study was performed to evaluate the flavour profiles of low-fat comminuted sausage (LFS) as affected by the addition of various concentrations of glucose, fructose and sucrose combined with 0.1 m lysine. Among thirty-five volatile compounds, the concentrations of furfural, 2-furan methanol, 2-methoxy phenol, 2-methoxy-4-methyl phenol, myristicine and pentadecanal occupied approximately 60% of the total concentration of volatile compounds identified in full- and low-fat smoked sausages. Phenols and hetero-compounds derived mainly from the smoking process were the predominant chemical groups. Nine volatile compounds were affected by fat content and the reduction of fat predominantly increased the headspace concentration of myristicin and pentadecanal. The headspace concentration of total volatile compounds detected in LFS control was significantly higher than those of LFS treatments with the various sugars and lysine. The headspace concentration of most volatile compounds decreased with the addition of various sugars. The results indicate that the addition of glucose, fructose and sucrose at the concentrations higher than 0.05 m in combination with 0.1 m lysine delays the release of some flavour compounds in LFS.
Penicillium sp NIOM-02 was isolated from the marine sediment, produced red pigment. The pigment extracted from this fungus scavenged 2, 2-diphenyl-1-pycrylhydrazyl (DPPH) radical. Penicillium sp NIOM-02 grown in media containing corn steep liquor scavenged 72–88% of DPPH radical. During solid-state fermentation on wheat (S1), the fungus produced more pigment (9.232 OD Units). Penicillium sp NIOM-02 grown on sugarcane bagasse scavenged 91% of DPPH radicals. It secreted more amylase (246 U mg−1) in culture medium No. 5 and the zymogram analysis revealed its molecular mass (53 kDa). The taka-amylase like character of amylase was determined by acarbose incorporated studies in the culture media. Production of pigment and radical scavenging activity of Penicillium sp NIOM-02, suggested its applications in food, pharmaceuticals and nutraceutical industries.
The effect of commerical olive oil refining processes on the total polyphenol and 1,2-diphenol content of the oil was investigated. the mean losses of total polyphenols and 1,2-diphenols of the crude oils were 84-87% and 79-88% respectively. There was no difference between the chemical and physical refining processes in reducing phenols in the oil samples.
Response Surface Methodology (RSM) was used to establish the optimum time and temperature for production of acid-hydrolysed winged bean protein (aHWBP) and acid-hydrolysed soybean protein (aHSBP). Seven hours of hydrolysis at 125 °C was the optimum condition for producing aHWBP, whereas it was 5 h of hydrolysis at 125 °C for production of aHSBP. Although aHWBP and aHSBP produced using these conditions had favourable sensory qualities, they were found to have up to 25 mg kg−1 of 3-monochloropropane-1,2-diol (3-MCPD). This exceeds the maximum level permissible in Commission Regulation (EC) No 466/2001. However, additional alkaline thermal treatment at pH 8.5 for 2 h at 100 °C effectively reduced the 3-MCPD contents of aHWBP and aHSBP to undetectable levels. aHWBP has a distinctive flavour, which is different from that of aHSBP. The former has higher mean scores for meaty and vegetable attributes but lower mean scores for soy, umami and beany attributes than the latter.
Commercial wheat germ lipase inactivation was analysed at various temperatures with reference to conventional and microwave heating. A temperature controlled water-bath was used for conventional heating. A custom designed microwave temperature control system was used to maintain test samples at selected temperatures either by full exposure to microwaves (microwave heating) or partial exposure by immersion in water (in a beaker) maintained at the desired temperature using the microwave oven (mixed mode). Lipase inactivation was analysed using first-order kinetics resulting in activation energies (Ea) of 20.9, 25.4 and 18.7 kcal mole-1 for the conventional, microwave and mixed mode heating, respectively. the activation energies of conventional and mixed mode heating were somewhat more comparable, while the microwave mode resulted in a slightly higher activation energy. the higher enzyme inactivation rate constants observed under microwave heating conditions were attributed to possible non-thermal effects associated with microwave energy
The non-edible portion of cauliflower (cauliflower waste) was subjected to drying by different methods. While conventional sun drying (CSD) took 1920 min to dry the waste, microwave drying (MWD) took only a few minutes. As against the L value of 41.27 in samples with fresh cauliflower waste, the sample dried at 50 °C showed L value of 38.16, and those dried at 200 °C indicated an L value of 16.61. Highest glucoamylase (GA) activity was found in the samples containing waste dried at 50 °C and the least in samples dried at 200 °C. However, in samples containing waste dried at 70 °C, using combinations, such as MWD and CSD, MWD and drying at 50 °C, CSD showed comparable GA activity. The results indicate that the sample dried using the combination of MWD and drying at 50 °C resulted in shorter drying period, good colour retention in the final product, and its incorporation resulted in significant enzyme production.
The heat resistance of Staphylococcus aureus NCTC 10652 in tris-maleate buffer pH 7.0 was increased by 4 or 8% w/v NaCl (P= 0.001). At pH 6.5 the D60°C in both buffer and meat macerate was increased by 8% w/v NaCl. Addition of NaNO2 had little effect on the heat resistance.
Ethyl acetate was found to be produced in large quantities in aged cultures of the soy yeast Saccharomyces rouxii NRRL Y-1096 grown on medium containing glucose. The synthesis of ethyl acetate was investigated. The present study shows that the process of ester synthesis is essentially an aerobic one. Glucose and ethanol were the main substrates for the synthesis of ethyl acetate although to a limited extent the yeast cells were also able to synthesize the ester from ethanol alone but not from either glucose or acetate. From the results of the present study, it is suggested that the flavour-producing moromi stage of soy-sauce fermentation is necessarily a prolonged one because ethanol has first to be produced in a semi-anaerobic environment for the synthesis of the esters responsible for the characteristic bouquet and flavour of the mature soy-sauce. It should therefore be possible to shorten this stage of soy-sauce fermentation by the addition of ethanol to the moromi.
The glucose metabolism of Saccharomyces rouxii NRRLY—1096, the soy yeast, under aerobic and anaerobic conditions, was investigated. The study was carried out at pH 4.5 and 7.0 with cells previously grown at either pH. The pH at which the cells had been grown as well as the pH at which glucose was fermented were found to affect the pattern of fermentation. A typical yeast type fermentation was obtained with cells grown at pH 4.5 and fermenting glucose at the same acid pH. An ability to fix CO2 for formic acid synthesis was demonstrated by cells grown at neutral pH. Acetic acid was produced by cells fermenting glucose at neutral pH irrespective of the pH at which they had been grown. Various schemes of glucose fermentation were therefore proposed. From results of the present study, optimal conditions for the formation of the desired fermentation products, resulting in the flavour and bouquet of good quality soy sauce, are suggested.
The effects of sodium chloride concentration, pH and temperature on the growth characteristics of Saccharomyces rouxii NRRLY-1096 are described. It was found that sodium chloride increased the lag phase of the growth curve and reduced the total amount of growth. Doubling time was less at 37°C during the exponential growth phase as compared to that at room temperature (28°C). Total amount of growth was however, greater at room temperature. Saccharomyces rouxii NRRLY-1096 grew over a wide pH range in the presence of relatively high concentrations of salt, but pH 4.0 to 6.0 was most favourable to its growth.
SummarySDS gel capillary electrophoresis (Beckman–Coulter ProteomeLab) and the lab-on-a-chip technology (Agilent 2100 Bioanalyzer) were used to quantify the relative amount of 7S and 11S fractions in twenty different soybean cultivars. The better repeatability of the migration times and peak areas was achieved for the Bioanalyzer. Both lab-on-a-chip instrument and a traditional capillary gel electrophoresis were shown to be adequate for analysis of soy-based products. Integrating the area of peaks within a certain range of molecular weights was used to calculate the relative content of each protein subunit. Poor agreement in the classification in the protein subunit groups between the two instruments was observed. Therefore, the approach of visual identification taking into account both the variability in the position of the peaks and the detection of different number of peaks between the profiles was applied. This resulted in statistically significant correlation being observed between 11S/7S ratios determined by Bioanalyzer and ProteomeLab (R = 0.82). The reported differences in 11S and 7S content between the studies are likely to be affected by the differences in the techniques used to analyse soy protein subunits. A brief presentation of the chemometric analysis of electrophoretic profiles as a common method for transforming electrophoretograms to multivariate data sets is shown.
The heat resistance of spores of Clostridium botulinum strain 213B heated in phosphate buffer (pH 7.0) was determined over the temperature range 120 to 140°C using a computer controlled thermoresistometer. The predicted D121°C value of approximately 0.13 min and z value of 11.0°C (obtained by linear regression) was close to the classical D121°C of 0.2 min and z value of 10°C used in process calculations. These data indicated that, according to the heat resistance of this culture, the z value of C. botulinum can be considered constant over the whole range 120 to 140°C. This also provided support for the recommended classical process calculations, using a z value of 10.0°C, being adequate if extrapolated to 140°C.
The effect of the addition of a β-glucan fibre fraction from barley to durum wheat pasta was evaluated in terms of cooking characteristics, structure, texture and in vitro starch digestibility. Barley β-glucan (BBG) fibre fraction was incorporated into pasta at 2.5%, 5%, 7.5% and 10% inclusion rates. Incorporation of the BBG fibre fraction to pasta attenuated reducing sugar release during in vitro digestion, the magnitude of reduction being related to the level of BBG fibre fraction inclusion. Changes to pasta cooking quality and texture were observed with BBG fibre fraction addition, including greater solid loss during cooking, increased pasta swelling and loss of hardness compared with the control pasta. Investigation of pasta microstructure and characterisation of starch gelatinisation events indicated that a combination of changes to the starch–protein matrix and the high water binding capacity of β-glucan alters the physico-chemical properties and digestibility of the pastas.
As aquaculture has developed, a range of bacterial diseases have been encountered that have caused both major production problems and animal welfare difficulties. These diseases were initially controlled almost exclusively by the use of antimicrobial agents. Fish farming is now a sufficiently large and mature an industry to have justified the development of an effective range of vaccines that have largely supplanted the use of antimicrobial agents for most bacterial diseases in salmonid farming in Europe and North America. For most salmonid bacterial diseases, use of antimicrobial agents is now largely confined to emergency use in the event of breakdown of vaccine protection. In addition to the increasing availability of vaccines, aquaculture is steadily developing a range of improved husbandry methods to reduce the impact of disease. Although there is evidence that antibiotic resistance can be selected for in normal therapeutic use in aquaculture, the risks of transfer of such resistance to human consumers by any of the possible routes appears to be low. Where new species are under development for aquaculture and during the development of these species, bacterial diseases may be expected to occur that will need use of antimicrobials for disease control before vaccines can be developed. If antimicrobials were not available for use with new species, development would be likely to transfer to countries with poorer controls on antibiotic use. Use of antimicrobial agents in ornamental fish, particularly in some exporting countries, is significant, and evidence exists that multiple antibiotic resistant bacteria may be frequent in such animals. Although ornamental fish are not eaten, they do enter homes and are in close contact with humans.
This work describes the application of high resolution 13C nuclear magnetic response (NMR) to the study of fatty acid composition in animal fats. It allows both the proportions of saturated, mono- and polyunsaturated fatty acid chains and the positional isomerism on glycerol to be determined. Olefinic carbon shifts gave quantitative information on the distribution of saturated, mono- and polyunsaturated fatty acid chains in animal fat triglycerides. Carbonyl carbon shifts gave information about the degree of saturation of fatty acid chains and their positions on the glycerol. The NMR values agree with the results from gas chromatographic analysis.
The fat content and fatty acid profiles of 14 varieties of date seeds were measured by gas chromatography–mass spectrometry (GC–MS). Fat content ranged from just over 5% (w/w) to about 9%. Eleven fatty acids were found with nearly 50% oleic acid in most varieties and an overall range from about 12 to 0.2%.
The differences between samples were ascribed to both varietal and cultural differences. Some varieties had similar names but it is not known whether they are identical.
The uses of dates seeds, which are currently only used for animal feed, is assessed with suggestions for potential uses as sources of edible oils and pharmaceuticals.
Dairy products are suitable vehicles for delivering beneficial microorganisms to consumers. Both Lactobacillus reuteri RC-14 and Lactobacillus rhamnosus GR-1 are considered as probiotic agents with therapeutic properties. The objective of this study was to monitor growth and survival of these bacteria in milk during storage period. Four formulations of milk (1% fat) with 0.33% yeast extract (Y), 0.4% inulin (I), 0.33% yeast extract and 0.4% inulin (YI) and one with no additives (N) were prepared. The mixtures were autoclaved for 15 min, cooled to 37 °C and inoculated with 1% of starter culture. They were then incubated anaerobically at 37 °C overnight. Viable numbers of L. reuteri RC-14 and L. rhamnosus GR-1 were determined after 1, 7, 14, 21 and 28 days of storage at 4 °C. Both bacteria were able to grow and survive in all samples; however, they showed a higher survival rate (P < 0.05) in YI treatment. After 1 day of storage, the total colony counts of treatment YI for L. reuteri RC-14 and L. rhamnosus GR-1 were 2 × 108 and 1 × 109 CFU mL−1, respectively. The total colony counts for treatment YI decreased by 1 log cycle for both bacteria after 28 days of storage. The results of this study indicate that these bacteria can remain viable over the storage period, and there is potential for incorporating them into fermented dairy products.
Protein extractability, muscle pH and organoleptic toughness have been measured in cod fillets stored for up to 34 weeks at −7°C and −14°C. The decrease in protein extractability and the increase in toughness of fillets stored at −7°C proceeded at a faster rate than in fillets stored at −14°C. In order to assess if a fillet stored at −7°C or −14°C had an acceptable or a tough texture it was necessary to measure both protein extractability and muscle pH.
SummaryA computer-controlled thermoresistometer for the determination of the heat resistance of bacterial spores has been designed and constructed. The thermoresistometer is capable of operating between 100 and 150°C0.1°C with exposusre times as short as 0.1 sec. Five samples (0.01 ml) of spore suspension can be exposed to steam at each time/temperature combination using a computer-controlled piston-driven exposure system. Temperature control of the apparatus is achieved using platinum resistance probes linked to the computer, which then actuates a variable steam control valve.
The effects of doses of gamma radiation of up to 16 Mrad on some plastic packaging materials have been studied in relation to properties considered desirable for the vacuum packing of fish. Nylon 11 appears to be the most suitable in terms of the tests applied.
In this study we investigate the spoilage of ultra high temperature UHT mango juice as well as a carbonated fruit juice blend to identify organisms contributing to the spoilage. The mango concentrate, the final product, as well as the other ingredients used during manufacturing, were tested for the presence of Alicyclobacillus by polymerase chain reaction (PCR) and sequencing analyses. Microbiological examination of the mango pureé and spoiled fruit juices, using YSG agar [yeast extract 2 g, glucose 1 g, soluble starch 2 g, pH 3.7 (adjust with 2N H2SO4), H2O 1000 mL, bacto agar 15 g] incubated at 55 °C, detected sporeforming, acid dependent and thermotolerant bacteria. The hyper variable region of the 16S rDNA was amplified. The nucleotide sequence of the PCR fragments was determined using the ABI Prism 310 automated DNA sequencer and the collected sequencing data were analysed and compared with the non-redundant database using NCBI-BLAST. Alicyclobacillus acidocaldarius were isolated and identified by 16S rDNA gene sequences analyses. The results indicated that the mango purèe, as well as the final product of mango juice and the fruit juice blend, were positive for Alicyclobacillus. The preventative measures of low pH, pasteurization of mango juice and the subsequent use of aseptic packaging were not regarded as sufficient to prevent the outgrowth of Alicyclobacillus spoilage organisms.
A molecular f(DNA) method based on 16S rDNA polymerase chain reaction (PCR) was developed by employing universal oligonucleotide primers followed by direct automated sequencing of the PCR amplicon. The employment of the methodologies allowed for the reliable identification of collection of eubacteria isolated from several food and water sources. Highly variable portions of the 16S rRNA sequence provided unique signatures to any bacterium and useful information about relationships between them. Employment of partial 16S rDNA PCR and sequencing provided a valuable and reliable method of identification of environmental bacteria associated with food and water.
In the hot breast and leg muscles of broiler chicken the level of ATP, the ‘R’ value, the lactic acid content, the pH value, the length of sarcomers, the water and fat retention capacity, the fat emulsion stability, thermal drip, and the extractability of protein fraction were investigated. It was found that in the breast muscles the onset of rigor mortis commenced within 30–60 min, and in the leg muscles as early as 15–30 min after killing of the birds. The deepest rigor mortis occurred between the first and fourth hour, and then gradually declined, sooner in the leg than in the breast muscles. The addition of sodium chloride (2.0–2.5%) to the minced pre-rigor meat not later than 40 min after slaughter, or better, an injection of NaCl brine into intact muscles 15 min after slaughter of birds, preserved their good technological properties.
The tenderness and the thermal drip of hot salted and chilled salted muscles showed no significant differences, but water retention and fat emulsifying capacity were better in the hot salted meat samples. The hot salted and cooked muscles were preferred by the sensory panel to corresponding samples of chilled muscles.
From the hot salted chicken meat more sarcoplasmic and myofibrillar proteins were extracted than from meat salted after chilling. However, after frozen storage the extractability of myofibrillar proteins were higher in the salted chilled meat.
This study examined the effect of lemon juice on sensory, biochemical and microbiological quality of sous vide (SV)-packaged bonito. Bonitos were salted (0.2%) and divided into two groups. The first group (SV) was vacuum-packaged in a gas barrier plastic pouch, pasteurised (70 °C, 10 min) and stored at 4 ± 1 °C. The second group [(lemon juice-treated sous vide (LSV)] was treated with lemon juice, vacuum-packaged, pasteurised and stored similarly. LSV samples had lower pH, mesophilic and psychrophilic aerobic counts than SV samples (P < 0.05), and they had better sensory quality. SV samples spoiled on the 35th day, while the LSV samples were acceptable until 49th day of storage. This result shows that treatment with lemon juice increased the acceptability and shelf life of SV packaged bonito for 2 weeks (40%). When compared to several other mild preservation procedures, addition of lemon juice to SV fish is inexpensive and uncomplicated method.
In the present study, chemical and sensory qualities of fish burgers prepared from deep flounder (Pseudorhombus elevatus Ogilby, 1912) with and without coating (Group A and Group B, respectively) or batter and breading materials were determined during frozen storage at −18 °C for 5 months. According the statistical results, Total volatile base nitrogen of two groups increased significantly (P < 0.05) but a significant decrease (P < 0.05) was observed at the third month for Group A. Thiobarbituric acid value of Group A decreased significantly (P < 0.05) with the storage time from 1.01 to 0.22, whereas a significant increase (P < 0.05) was observed for Group B from 0.15 to 0.62 at the end of storage time. There were significant differences of pH in either the Group A or Group B between the beginning and end of the storage periods (P < 0.05). Parameters of colour, texture, taste and general acceptability for two groups decreased (P < 0.05) but Group B indicated better scores than Group A at the end of the storage period.
Chicken soup was made from the broth collected after the pressure cooking of deboned chicken frames (bones). The quality of stored chicken soup (S1) was compared with the soup prepared from the stored chicken broth (S2) at refrigerated (4 ± 1 °C) and frozen (−18 ± 1 °C) storage up to 12 and 90 days, respectively. Thiobarbituric acid reactive substances values and microbial counts were significantly (P < 0.01) higher in stored soup (S1) compared with fresh soup (S2). Psychrotrophs and coliforms were not detected. Appearance and odour scores of broth were satisfactory throughout the storage. Sensory attributes were rated better for fresh soup (S2) made from stored broth than stored soup (S1) but all the attributes were decreased with increasing storage period. The stored soup was acceptable up to 9 and 90 days in refrigeration and frozen storage respectively, while the soup made from refrigerated stored broth was acceptable for 12 days.
Wild sea bass (Dicentrarchus labrax) captured from north eastern Mediterranean in autumn and winter were stored at −18 °C, and their chemical and sensory quality were investigated for up to 9 months. At the end of autumn storage period, pH, total volatile basic nitrogen, thiobarbituric acid values, free and bound formaldehyde, free formaldehyde and protein solubility were 6.69, 15.59 mg 100 g−1, 0.086 mg MA kg−1, 1.23 mg kg−1, 3.58 mg kg−1 and 15.72 g 100 g−1, respectively. The same parameters for winter storage were 6.55, 12.08 mg 100 g−1, 0.308 mg MA kg−1, 3.38 mg kg−1, 4.95 mg kg−1 and 14.39 g 100 g−1, respectively. None of the chemical quality parameters exceeded the acceptability limits. These results were supported by the results of sensory analyses (colour, odour, flavour, texture and overall acceptability). It was also concluded that differences in initial proximate composition and chemical quality scores of wild sea bass captured in autumn and winter did not have an effect on the chemical and sensory quality during frozen storage.
Fresh samples of whole and gutted anchovies were blast frozen at −35°C and stored at −18°C. The quality of the samples was examined as organoleptic, microbiological and chemical changes during the storage period. Gutting had no significant effect on the quality of the final product. Sensory quality was good for up to 90 days of storage. No increase in microbial activity was detected, but some oxidative and hydrolytic deterioration of fats were observed. The final product was still edible after 180 days.
Ascorbic acid (AA) degradation and colour changes, measured by the lightness index (L*), were determined in cashew apples (at low dissolved O2 concentrations) heated at high temperature (100–180 °C) in a hermetically sealed cell. A nonisothermal method was developed to estimate thermal degradation kinetics. The results showed that reaction kinetics during heat treatments were well represented by first-order reactions. The temperature dependence of the kinetic constants was described by an Arrhenius type equation. The activation energy (Ea) for AA degradation and lightness index were 94 ± 3 and 98 ± 3 kJ mol−1, respectively. The reaction rate constant at 140 °C for AA degradation (64 × 10−5 ± 3 × 10−5 s−1) was twice that for the lightness index change (33 × 10−5 ± 2 × 10−5 s−1). Results allow generating temperature profiles of heat processes that would help preserve the AA of cashew apples as well as control the colour formation during high-temperature processes.
Chemical, microbial and sensory quality indices of raw and marinated sea urchin Paracentrotus lividus Lamark, 1816, were determined. Marinades were prepared using three different formulations and stored over a 75-day period at 6 °C, under vacuum and air (control) packaging conditions. Significant differences were found between chemical (pH, moisture, ash, NaCI, ammonia and lactic acid), microbial [pseudomonads (Ps), lactic acid bacteria (LAB) and yeast–moulds] and sensory analysis of three different marinated groups (P < 0.05) during the storage period. The marinating process did not lead to significant differences in fatty acid, protein, fat and carbohydrate contents relative to raw sample. A notable decrease of the ω-3 per ω-6 ratio after marinating and during storage in both packages was observed. Ammonia concentration changes were found to be useful as index of freshness and decomposition of roe in storage. Shelf life of roe marinades at 6 °C was found to be 75 and 60 days under vacuum and air storage conditions respectively.
Production of a dry sausage from African catfish and determination of its microbial, chemical and sensory properties during a 70-day storage at both 4 and 22 °C were prompted. pH of the samples at 4 and 22 °C did not significantly change during the storage (P > 0.05). Moisture content of the samples was 74%, and reduced to 45% at 4 °C and to 22% at 22 °C. Protein content of the samples was 20.71%, and increased to 42.5% at 4 °C and to 57.99% at 22 °C. Total lipid content was 4.5%, and increased to 10.98% at 4 °C and to 15.68% at 22 °C (P < 0.05). Microbial analyses showed that there was a significant reduction in total aerobic mesophilic and psychrotrophilic bacteria, total mould and yeast, total lactic acid bacteria, total Enterobacteriaceae and Staphylococcus aureus counts at both 4 and 22 °C (P < 0.05). Samples stored at 4 °C had significantly higher sensory ratings than that of the samples stored at 22 °C (P < 0.05).
The aims of this study were to evaluate the nutritional quality (proximate composition, amino and fatty acid profiles, cholesterol and mineral contents) of African catfish (Clarias gariepinus) and determine the effect of different cooking methods (grilling, boiling and frying) on biochemical composition. Frying produced the highest water loss and fat gain (P < 0.05). Frying also affected the fatty acid composition significantly (P < 0.05), increasing oleic (18:1n-9) and linoleic (18:2n-6) acid contents. The major essential amino acids were arginine and lysine, and the limiting was the sulphur amino acid methionine. The changes in the cholesterol and mineral contents (K > P > Na > Mg > Ca > Zn > Fe > Cu > Mn) and nutrient-recommended dietary intakes are discussed and several indices (chemical score, amino acid score, essential amino acid index, biological value, nutritional index, retention values, atherogenic index, thrombogenic index and hypercholesterolaemic potential) are presented. The valorisation of these products may stimulate the development of aquaculture production and consumers’ interest in Europe.
Chemical, microbial and sensory quality aspects of the marinated ascidia Microcosmus sabatieri Roule, 1885, were examined over a 150-day period at 6 °C, under vacuum and air (control) packaging conditions using three different formulations (with 12% sodium chloride and 3%, 5% or 7% acetic acid). Significant differences were found between chemical and sensory analysis of three different marinated groups (P > 0.05) during the storage period. There were also significant differences in pseudomonads, lactic acid bacteria and yeast and moulds of the marinated groups by which lower bacterial counts were determined. N-3 polyunsaturated fatty acids concentrations decreased significantly (P < 0.05), while total viable counts, ammonia and total saturated fatty acid concentrations increased significantly (P > 0.05) in all three groups during storage. The differences in fatty acid and ammonia concentrations were found to be useful as indexes of freshness and decomposition of marinated M. sabatieri in storage. Shelf life of M. sabatieri marinades was found to be 5 and 4 months under vacuum and air (control) packaging conditions respectively, at 6 °C.
Results of 188 analyses for aflatoxin in edible nuts imported into the U.K. during 1982–84 are presented. Most samples (140/188, 74%) had aflatoxin B1, content ≤ 5 μg/kg. Brazilian peanuts may be identified as consistently unreliable as regards aflatoxin contamination.
In a survey of aflatoxins B1, B2, G1, G2 and ochratoxin A in 209 ungraded and graded samples from the 1989 Saudi Arabian wheat crop, only one sample was found to contain ochratoxin (1.8 μg Kg-1) and a trace of aflatoxin.
Response surface methodology was used to study the production of acid casein from skim milk powder and to investigate the effects of pH, concentration and washing conditions (agitation, time, temperature and wash water ratio) on the end product. The washed curd was analysed for residual ash, minerals and lactose. The critical variables were found to be concentration and pH in relation to mineral content; and concentration and washing time for lactose. Surface response methodology provides a unique insight into the relationships between the variables related to the process and the results are used to explain the observations in terms of milk chemistry. The washing process was further evaluated in terms of the Murphree Stage Efficiency to elucidate the effect of the number of washing stages on residual whey components in the casein curd. This study contributes to understanding the extrusion process of skim milk powder which makes use of higher milk solids concentrations.
The present study has been devised to prepare prime (67% lean), choice (57% lean + by-products) and economy (47% lean + by-products + extenders) chicken emulsions from broiler spent hens and to evaluate quality of these emulsions at refrigerated (4 ± 1 °C) storage to be used as semi-convenience product by preparing chicken patties. The variables studied were, pH, emulsion stability, proximate composition, TBARS number, colour and odour changes and microbiological parameters [standard plate count (SPC), psychrotrophic count, staphylococcal count, streptococcal count, Coliform count, yeast and mould count and detection of salmonella], patties yield, texture and acceptability. Prime and choice emulsions were found superior to economy both in fresh and stored conditions. SPCs increased during storage period and approached 7 log10 CFU g−1 counts in choice and economy formulations, while psychrotrophic counts exceeded 6 logs on day 12. Counts of pathogens (streptococci and staphylococci) decreased during storage indicating decreased risks of stored emulsions from these microbes and salmonella were absent. Refrigerated storage of prime, choice and economy formulations up to 12 days resulted in chicken patties of high acceptability without adverse effect on any of the sensory attributes. All the three emulsions were found suitable as semi-convenience product both on microbial quality of emulsions and yield and palatability of patties for prestoring at 4 ± 1 °C for 9 days.
1H NMR spectroscopy was used to determine first order rate constants at four temperatures (300, 304, 308, 312 K) and activation energies of the autoxidation reaction for oxymyoglobin. the haeminic pigment was purified from two bovine muscles with different colour stabilities (psoas major (PM) and longissimus lumborum (LL)) at 2h (day 0) and 192 h (day 8) post mortem. to characterize this autoxidation reaction, we have focused attention on the time-temperature dependent disappearance of the Val-E11 methyl group signal. This study showed that, whatever the time post mortem, although the myoglobin autoxidation rate was greater for PM than for LL muscle, the activation energies were similar. It was also worth noting that, in the range 300–312 K, the average ratio of autoxidation rate constants between day 8 and day 0 was near 1.6 for the two muscles studied. It is reasonable to think that oxidative processes developed during 8 days meat storage have led to a structural change within the cavity of the heme pocket of the myoglobins. Moreover, only one orientation of the porphyrin within the heme pocket was noted for the two muscles studied.
Six accessions [three with maroon-coloured seed coat and three with white-coloured seed coat) of sword bean (Canavalia gladiata (Jacq.) DC.], were collected from six different locations in south India. They were analysed for their proximate and mineral composition, amino acid profiles of total seed proteins, in vitro protein digestibility (IVPD) and certain antinutritional factors. The essential amino acid profile of total seed proteins compared favourably with FAO/WHO requirements, except that there were deficiencies of sulphur containing amino acids in all the six accessions and also the leucine, lysine and tryptophan contents were low in maroon-coloured seed coat accessions. The IVPD of the accessions ranged from 63.39 to 76.92%. Antinutritional substances like total free phenolics, tannins, l-DOPA (3,4-dihydroxyphenylalanine), trypsin inhibitor activity and phytohaemagglutinating activity were also investigated. The antinutritional factors that were detected were thought to have little nutritional significance if the beans are properly processed.
Functional foods, also known as nutraceuticals, medical foods or nutritional foods, are driving food markets around the world and are expected to be one of the emerging trends for the food industry in the new millennium. The concept of functional foods is rooted in a tradition, particularly in Asia, where people have always believed that a balanced diet and some herbal foods are therapeutic. However, while extensive studies in biochemistry and immunology, as well as clinical trials, have been conducted on selected functional foods or ingredients, the scientific features of most traditional herbals remain almost unknown. However, the fastest growing food market in the United States is that of herbal-based nutraceuticals such as ginseng, garlic and medical mushrooms. This review describes different aspects of functional foods and the Chinese medicated diet on the basis of current knowledge, discusses the building blocks for the science of functional foods and proposes a possible way to fuse a Chinese medicated diet into functional foods.
Critical control points (CCPs) were identified in the risk assessment of octopus (Octopus vulgaris) processing and implemented in the hazard analysis critical control point (HACCP) plan. In the hazard analysis worksheet the different hazards were identified at each processing stage, whereas in the HACCP plan each CCP is identified and accompanied with the relevant significant hazard, critical limit, monitoring of the CCP and corrective actions. In this work comparison of ISO 22000 analysis with HACCP is carried out over octopus processing and packaging. ISO 22000 Analysis Worksheet was employed for determination of some prerequisite programmes (PrPs). Comparison between the two systems has been carried out using the hazard analysis worksheet. The PrPs are the main difference between the two systems. The incorporation of PrPs in the ISO 22000 made the system more flexible as a smaller number of CCPs was introduced.
This work studied the cultivation conditions for the production of carotenoids by Sporidiobolus salmonicolor (CBS 2636) in a bioreactor. A Plackett–Burman design was used for the screening of the most important factors, followed by a complete second order design, to maximise the concentration of total carotenoids. The maximum concentration of 3425.9 μg L−1 of total carotenoids was obtained in a medium containing 80 g L−1 glucose, 15 g L−1 peptone and 5 g L−1 malt extract, with an aeration rate 1.5 vvm, 180 r.p.m., 25 °C and an initial pH of 4.0. Fermentation kinetics showed that the maximum concentration of total carotenoids was reached after 90 h of fermentation. Carotenoid bio-production was partially associated with cell growth. The specific carotenoid production (YP/X) was 238 μg carotenoids/g cells, whereas YP/S (substrate to product yield) was 41.3 μg g−1. The specific growth rate (μx) was 0.045 h−1. The highest cell and total carotenoid productivity were 0.19 g L−1 h−1 and 56.9 μg L−1 h−1, respectively.
Freshly caught sardines contained high levels of bacteria located mainly on the skin and the gills. These bacteria invaded and grew rapidly in sardine muscle, reaching 5x108 c.f.u. g-1 and 6x108 c.f.u. g-1 respectively after 24h at ambient temperature and 8 days in ice.
Histidine, arginine, lysine, tyrosine and methionine levels decreased during storage. The other amino acids, except proline and taurine, accumulated in the fish muscle, indicating an extensive proteolysis.
Histamine, cadaverine and putrescine accumulated to levels of 2350ppm, 1050ppm and 300ppm respectively, after 24h storage at ambient temperature. Histamine and cadaverine reached similar levels after 8 days storage in ice, whereas putrescine formation was insignificant. Spermidine and spermine levels increased slightly under ambient conditions.
Salting the fish at 8% delayed bacterial and chemical changes but only in iced sardines.
The high content of free histidine found in sardines and the susceptibility of its muscle to histamine and cadaverine formation could explain its increasing implication in incidents of histamine poisoning.
Summary The efficacy of nisin at three different concentrations, 12.5, 25 and 50 ppm, on the keeping quality of fish sausage in synthetic casing at ambient (28 ± 2 °C) and refrigerated (6 ± 2 °C) temperatures was assessed. Gel strength, expressible water content, total volatile base nitrogen, total plate count and aerobic spore counts were affected by the storage temperatures and nisin concentrations used. Fish sausage treated with 50 ppm of nisin was acceptable after storage at ambient temperature for 20–22 days compared with the control, which were acceptable only for 2 days. The keeping quality of the sausages, at refrigerated temperature, varied from 30 days in the control to 150 days in 50-ppm nisin-treated samples. The residual nisin decreased slowly in samples stored at refrigerated temperature, whereas, in fish sausages stored at ambient temperature, the decrease was rapid. Nisin at 50-ppm level showed a significant effect (P ≤ 0.05) on the gel strength and overall acceptability scores both at ambient and refrigerated temperature.
Functionality of black sesame seed methanol extracts (BSME) including radical scavenging activity and apoptotic effects on human colon cancer cell lines were measured. Radical scavenging activities of BSME was determined by 2,2′-diphenyl-1-pycryl-hydrazil (DPPH) and 2,2′-azino-bis [3-ethylbenzthiazoline-6-sulphonic acid (ABTS)]methods. Total phenolic contents (TPC) were also measured. Cell toxicity effects of BSME on human colon cancer cell HT-29 were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and apoptotic effects were tested by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labelling (TUNEL) assay and reverse transcription-polymerase chain reaction (RT-PCR) expressions of BCL-2 and BAX. TPC of BSME was 4.80 ± 0.21 μm tannic acid equivalent mg−1 BSME. DPPH and ABTS radical scavenging abilities by BSME in EC50 were 27.10 and 6.12 mg mL−1 BSME, respectively. Concentration from 6.7 to 10.0 mg mL−1 BSME exhibited proper cell toxicity based on the results of MTT assay and was enough to increase the apoptosis of colon cancer cells with typical apoptotic characteristics from TUNEL assay. In RT-PCR, 6.7–10.0 mg mL−1 BSME reduced the expression of BCL-2 and increased the expression of BAX, compared with untreated controls. BSME possessing phenolic compounds with radical scavenging ability may be related with inducing colon cancer cell death.