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Basic Nitrogen (basic + nitrogen)
Kinds of Basic Nitrogen Selected AbstractsRELATION BETWEEN THE FREE AMINO ACIDS, ANSERINE AND THE TOTAL VOLATILE BASIC NITROGEN PRODUCED IN MUSCLE OF HAKE (MERLUCCIUS MERLUCCIUS, L.) DURING ICED STORAGEJOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2002CLAUDIA RUIZ-CAPILLAS This work studied the development of free amino acids (FAAs) and dipeptide anserine as quality indices for gutted hake stored in ice for 25 days. The correlation of these compounds was determined with total volatile basic nitrogen (TVBN) which has been used as a quality index, for fish stored in ice. The most abundant free amino acids in hake muscle were found to be threonine, glycine, alanine, glutamic acid, ,-alanine methylhistidine. lysine and the dipeptide, anserine. The only hydrophobic free ammo adds which exhibit significant differences (P<0.05) throughout storage was tryptophan. moreover, this amino acid exhibited a very high correlation (r=0.951) with TVBN. A significant decrease in anserine (P<0.05) correlated with the increases in 1-methylhistidine and ,-alanine throughout storage. These changes also exhibited a very high correlation with TVBN. Therefore, 1-methylhistidine, ,-alanine anserine and tryptophan could be used as quality parameters for hake stored in ice. [source] Characterisation of the volatiles of yellowfin tuna (Thunnus albacares) during storage by solid phase microextraction and GC,MS and their relationship to fish quality parametersINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2007Ranjith K.B. Edirisinghe Summary Investigations were carried out to extract the volatile compounds of fish using solid phase microextraction (SPME) in order to develop a new rapid indicator for determining the quality of fish. Changes in the aroma composition of yellowfin tuna (Thunnus albacares) was studied at 30 °C and in ice, using SPME GC,MS, and their relationship with the fish quality parameters , total volatile basic nitrogen and sensory analysis , was determined using principal component analysis (PCA) and stepwise multiple regression analysis. Hexanal (30.9%) and 2-nonanone (28.4%) were recorded in relatively high amounts in fresh fish, whereas 3-methyl-1-butanol and 3-hydroxy-2-butanone increased with storage time. PCA clearly differentiated the volatile profile of each sampling stage (P < 0.05) throughout storage treatments. Regression analysis showed a significant relationship between the fish quality and the levels of 3-methyl-1-butanol and pentadecane. The findings highlight the possibility of developing a rapid quality evaluation method for fish using SPME GC,MS. [source] RELATION BETWEEN THE FREE AMINO ACIDS, ANSERINE AND THE TOTAL VOLATILE BASIC NITROGEN PRODUCED IN MUSCLE OF HAKE (MERLUCCIUS MERLUCCIUS, L.) DURING ICED STORAGEJOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2002CLAUDIA RUIZ-CAPILLAS This work studied the development of free amino acids (FAAs) and dipeptide anserine as quality indices for gutted hake stored in ice for 25 days. The correlation of these compounds was determined with total volatile basic nitrogen (TVBN) which has been used as a quality index, for fish stored in ice. The most abundant free amino acids in hake muscle were found to be threonine, glycine, alanine, glutamic acid, ,-alanine methylhistidine. lysine and the dipeptide, anserine. The only hydrophobic free ammo adds which exhibit significant differences (P<0.05) throughout storage was tryptophan. moreover, this amino acid exhibited a very high correlation (r=0.951) with TVBN. A significant decrease in anserine (P<0.05) correlated with the increases in 1-methylhistidine and ,-alanine throughout storage. These changes also exhibited a very high correlation with TVBN. Therefore, 1-methylhistidine, ,-alanine anserine and tryptophan could be used as quality parameters for hake stored in ice. [source] USING GELATIN-BASED ANTIMICROBIAL EDIBLE COATING TO PROLONG SHELF-LIFE OF TILAPIA FILLETSJOURNAL OF FOOD QUALITY, Issue 3 2002CHAN-YIN OU Skinless tilapia (Dreochromis niloticus x D. aureus) fillets were covered with a gelatin coating containing benzoic acid as an antimicrobial agent. Benzoic acid content of fish fillets was used to estimate the amount of gelatin coated on fillet surface, and it was found that the gelatin contents were between 16.3 mg and 17.3 mg per g of fillets. Aerobic and anaerobic microbial loads, volatile basic nitrogen (VBN) contents, and sensory evaluation were used as indicators to survey the feasibility of an antimicrobial gelatin coating to prolong the shelf-life of tilapia fillets under refrigeration. After 7 days of storage under refrigeration, tilapia fillets coated with gelatin containing benzoic acid had acceptable VBN contents, increased moderately in microbial loads, and showed no significant sensory difference (P < 0.05) from fresh fillets. The results indicate that an antimicrobial gelatin coating is suitable for preservation of tilapia fillets. [source] Effect of Thawing and Cold Storage on Frozen Chicken Thigh Meat Quality by High-Voltage Electrostatic FieldJOURNAL OF FOOD SCIENCE, Issue 4 2010Chang-Wei Hsieh ABSTRACT:, One of the most popular issues in electrostatic biology is the effects of a high-voltage electrostatic field (HVEF) on the thawing of chicken thigh meat. In this study, chicken thigh meat was treated with HVEF (E-group), and compared to samples stored in a common refrigerator (R-group), to investigate how HVEF affects chicken thigh meat quality after thawing at low temperature storage (,3 and 4 °C). The results showed that there were no significant differences in biochemical and microorganism indices at ,3 °C. However, the HVEF can significantly shorten thawing time for frozen chicken thigh meat at ,3 °C. After thawing chicken thigh meat and storing at 4 °C, the total viable counts reached the Intl. Commission on Microbiological Specification for Foods limit of 107 CFU/g on the 6 and 8 d for the R- and E-group, respectively. On the 8th d, the volatile basic nitrogen had increased from 11.24 mg/100 g to 21.9 mg/100 g for the E-group and 39.9 mg/100 g for the R-group, respectively. The biochemical and microorganism indices also indicated that the E-group treatment yielded better results on thawing than the R-group treatment. The application of this model has the potential to keep products fresh. [source] Lysosomal sequestration of amine-containing drugs: Analysis and therapeutic implicationsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2007Allyn M. Kaufmann Abstract Amine-containing drugs represent a very important class of therapeutic agents, with the majority of all drugs containing at least one basic nitrogen. For many decades, it has been known that weakly basic compounds can be sequestered into acidic organelles such as lysosomes. Some amines can achieve very high concentrations and induce a dramatic expansion (vacuolization) of the compartment. In the early 70s, Nobel laureate and discoverer of lysosomes, Christian de Duve et al. wrote an elegant commentary describing the theoretical basis for lysosomal sequestration of amines, referring to the process as pH-partitioning and the substrates as lysosomotropics. Recently, a resurgence of interest in the intracellular distribution of drugs has occurred considering its therapeutic importance. Specifically, lysosomal sequestration of amines has received considerable attention for reasons including its involvement in drug resistance, inducement of phospholipidosis, and its influence on whole body distribution/pharmacokinetics. Moreover, the sequestration phenomenon has been recently exploited in the development of a novel drug targeting strategy. This review will focus on these occurrences/developments and conclude with a commentary on the expected impact that knowledge regarding the intracellular distribution of drugs will likely have on future drug development processes. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 729,746, 2007 [source] Microbiological, chemical and sensory changes of whole and filleted Mediterranean aquacultured sea bass (Dicentrarchus labrax) stored in iceJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2003Dimitra Taliadourou Abstract The effect of filleting on the microbiological, chemical and sensory properties of aquacultured sea bass (Dicentrarchus labrax) stored in ice was studied. Pseudomonads, H2S-producing bacteria (including Shewanella putrefaciens) and Brochothrix thermosphacta were the dominant bacteria at the end of the 16 day storage period in ice for both whole ungutted and filleted sea bass. Enterobacteriaceae were also found in the spoilage microflora of whole ungutted and filleted sea bass, but their counts were always lower than those of pseudomonads, H2S-producing bacteria (including S putrefaciens) and B thermosphacta. Total viable counts for whole ungutted sea bass were always lower than those for filleted sea bass samples. Of the chemical indicators of spoilage, TMA (trimethylamine) values of whole ungutted sea bass increased very slowly, whereas significantly higher values were obtained for filleted samples, with respective values of 0.253 and 1.515 mg N per 100 g muscle being reached at the end of their shelf-life (days 13 and 9 respectively). TVB-N (total volatile basic nitrogen) values showed a slight increase for whole ungutted sea bass during storage, reaching a value of 26.77 mg N per 100 g muscle (day 13), whereas for filleted fish a corresponding value of 26.88 mg N per 100 g muscle was recorded (day 9). TBA (thiobarbituric acid) values increased slowly for whole ungutted and filleted sea bass samples throughout the entire storage period, reaching final values of 4.48 (day 13) and 13.84 (day 9) mg malonaldehyde kg,1 respectively. Sensory assessment of raw fish using the EC freshness scale gave a grade E for up to 5 days for whole ungutted sea bass, a grade A for a further 4 days and a grade B for an additional 4 days, after which sea bass was graded as C (unfit). Overall acceptability scores for odour, taste and texture of cooked whole ungutted and filleted sea bass decreased with increasing time of storage. The results of this study indicate that the shelf-life of sea bass stored in ice, as determined by overall acceptability sensory scores and microbiological data, is 8,9 days for filleted and 12,13 days for whole ungutted fish. Copyright © 2003 Society of Chemical Industry [source] Combination of bulk storage in controlled and modified atmospheres with modified atmosphere packaging system for chilled whole gutted hakeJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2001Claudia Ruiz-Capillas Abstract Whole gutted hake placed in boxes of ice were kept in modified and controlled atmospheres for 12 days with the gas mixture 60%CO2/15%O2/25%N2 (v/v/v) at 2,±,1,°C. Each lot of hake was then subdivided into two other lots and these were packed on trays, some of them in air and some in the same mixture of gases. The trays were kept at 2,°C until spoilage. The shelf-life of the hake stored in these conditions was assessed by physical (pH), chemical (TVBN (total volatile basic nitrogen) and TMA-N (trimethylamine nitrogen)) and sensory (inspection and taste panel) analyses. The results of these analyses indicated that the control lot (stored in air throughout) was rejected before the lots kept in adjusted atmospheres. However, the taste panel accepted all the lots, including the control lot, after 24 days of storage. The sample which was kept at 2,°C in a controlled atmosphere for 12 days and then packed in a modified atmosphere of the same gas mixture did not exceed pH 7 after 31 days of storage, nor the limits of TVBN and TMA-N of 40 and 12,mg per 100,g respectively. As regards oxidative rancidity, TBA (2-thiobarbituric acid) levels were very low under all storage conditions and did not exceed 2.5,mg malonaldehyde per 100,g muscle. According to the results of this study, bulk storage of whole gutted hake in boxes in ice under a controlled atmosphere could be combined with later packaging in a modified atmosphere on trays stored at 2,°C to extend the shelf-life of the hake. © 2001 Society of Chemical Industry [source] Changes in the quality of abalone (Haliotis asinina Linnaeus) packaged under atmospheric air, vacuum and modified atmospherePACKAGING TECHNOLOGY AND SCIENCE, Issue 3 2008Romanee Sanguandeekul Abstract Changes in the quality of abalone (Haliotis asinina Linnaeus) meat packaged under modified atmosphere (MA) of 40% CO2/30% O2/30% N2, vacuum and atmospheric air in polyvinylidene chloride (PVDC)/nylon/oriented polypropylene (OPP) pouches, and stored at 2 ± 1°C were investigated. Biochemical indices, such as pH, total volatile basic nitrogen (TVB-N), and trimethylamine (TMA) and sensory evaluation, as well as total plate counts of packaged abalone meat were determined periodically. TMA was not affected by the packaging conditions, and remained low during storage periods. A decrease in pH of the MA packaged abalones during the storage reflected the apparent absorption of CO2. The content of TVB-N slowly increased in the MA packaged abalone, whereas those stored in atmospheric air markedly increased during the storage. The sensory quality of MA packaged abalones was shown to be acceptable up to 15 days, while atmospheric and vacuum-packaged abalones were not acceptable after 3 days of storage. Copyright © 2007 John Wiley & Sons, Ltd. [source] Quality preservation of salted, vacuum packaged and refrigerated mahi sefid (Rutilus frisii kutum) fillets using an onion (Allium cepa) extractAQUACULTURE RESEARCH, Issue 8 2010Mehdi Zolfaghari Abstract The combined effect of light salting, vacuum packaging and onion extract on the shelf life of mahi sefid (Rutilus frisii kutum) fillets under refrigeration was assessed using chemical, microbiological and sensory methods. The shelf life of control, air-packaged, salted (APS), vacuum-packaged, salted (VPS) and vacuum-packaged, salted with onion extract (VPSOE) samples was determined to be up to 6, 9, 15 and 18 days respectively. The values of total volatile basic nitrogen, free fatty acid and thiobarbituric acid increased progressively during the storage period for all the treatments. However, the preservative methods applied led to an extended shelf life of fillets based on chemical indices and sensory attributes in the following order: VPSOE>VPS>APS>control group. The assay of the total viable count (TVC) revealed that 2% and 4%VPSOE produced a decrease in TVC throughout the storage period. According to the results obtained, the best method to preserve the mahi sefid fillet was by 4%VPSOE treatment. [source] | ||||||||||