To read the full-text of this research, you can request a copy directly from the authors.
ABSTRACTA chemical quality index of canned tuna was established for estimating the extent of decomposition in fresh tuna prior to canning. Histamine has frequently been used as such an indicator but by itself it has not always proved useful. The relationship of 5 amines (histamine, putrestine, cadaverine, spermine and spermidine) was studied to generate a chemical index of tuna decomposition. The amines were extracted from authentic pack and commercially prepared canned tuna samples. The dansyl derivatives were formed and determined by reverse phase, linear gradient elution, high pressure liquid chromatography. An index was developed from the individual amines and the resulting chemical indices scores compared favorably to organoleptic and authentic pack value scores.
Request the article directly from the authors on ResearchGate.
... Small amounts of bioactive amines occur naturally in fish (Table 13.9). Under normal physiological conditions, fish muscle contains high levels of spermine and spermidine and low levels of histamine and putrescine (9,68,118). ...
... Studies have indicated that the levels of spermine and spermidine decrease and those of putrescine and histamine increase during storage and deterioration of fish such as tuna, rainbow trout, salmon, sardine and some fresh water fish, e.g. snapper, carp, catfish, 'tambaqui', 'lambari' and 'tilápia' (23,43,67,118). There is also formation and accumulation of cadaverine, tyramine, tryptamine and phenylethylamine. ...
... There is also formation and accumulation of cadaverine, tyramine, tryptamine and phenylethylamine. The rates of change, however, are affected by storage temperature, pH, oxygen, nutrients presents, incorporation of additives and packaging system (1,23,117,118,142,195,207). Studies on the influence of temperature on histamine formation by Morganella morganii and Hafnia alvei, prolific histamine formers, indicated that at 1°C, no histamine was formed, whereas at 19 and 30°C, highest levels were found (7). ...
... In view of the relevance of biogenic amines for food safety issues as emphasized above, it is important to monitor their levels in fish. Besides histamine, such secondary amines as putrescine and cadaverine are good indices of spoilage of marine fish (Mietz and Karmas, 1977). For instance, Haláz, et al. 1994; Rezaei, et al. 2007 reported that putrescine and cadaverine in refrigerated foods (e.g. ...
... Křížek, et al. (2004) have suggested that PUT and CAD and the sum of both amines are useful quality indicators for common carp flesh, In addition, PUT values lower than 10 mg kg −1 can represent the good quality of the common carp flesh, 10–20 mg kg −1 as acceptable quality and the value over than 20 can indicate the poor quality established on sensory evaluation (Hernández, et al. 2010). Mietz and Karmas (1977) claimed a strong dependence of histamine content upon the fish species, and accordingly proposed a biogenic amine index, BAI, calculated as (C putrescine +C cadaverine +C histamine )/(1+C spermidine +C spermine ) where C denotes concentration expressed in mg/kg; they suggested that BAI values exceeding 10 are an indication of excessive quality loss, and said statement was corroborated by Mendes (1999) after examining histamine formation in sardines and mackerel. ...
... These low levels are consistent with the results reported by Rabie, et al. 2009 to salted fermented fish (Feseekh), and for various sea fish species, e.g. salmon, rockfish, lobster and shrimp (Mietz and Karmas, 1977). ...
The levels of biogenic amines were assessed throughout storage at 4ºC, for up to 120 days, of canned sardines, anchovy and smoked fish. Histamine, tyramine, putrescine, cadaverin, spermidine and spermine levels increased in general with elapsing storage time; the concentrations of the former in sardine, anchovy and smoked fish reached maxima of 281.17 mg/kgdry weight (DW), 166.21 mg/kgDW and 104.51 mg/kgDW, respectively, by 120 days. Spermidine and spermine levels increased slightly, whereas significant differences were found (P<0.05) in the levels of cadaverine and putrescine throughout storage. The total amine contents (579.15 mg/kgDW) of anchovy were highest, followed by sardine (456.86 mg/kgDW) and smoked fish (210.79 mg/kgDW). Overall, canned anchovy and sardine appear to pose public health risks owing to their biogenic amine levels above accepted thresholds.
... Putrescine (Put), spermine (Spm) and spermidine (Spd) were extracted and determined in both shoots and roots of turnip and lettuce according to Mietz and Karmas (1977), Maijala and Eerola (1993) ...
The present study was conducted to investigate the impact of irrigation with industrial wastewater on soil and plant. For these purpose turnip and lettuce plants were cultivated in soil irrigated with wastewater then heavy metals content of the soil, plant growth, yield and the subsequent changes in biochemical constituents of plant were examined. Irrigation with wastewater was found to load the soil with heavy metals (Pb, Co, Ni and Cd) that were not detected in soil before irrigation. The magnitude of Cd in soils after irrigation with industrial wastewater exceeds the maximum allowable limit (3 mg Kg-1). Both turnip and lettuce exhibited significant decreases in leaf area, fresh weight and dry weight of shoots and roots as well as all the measured yield components in response to wastewater irrigation. The magnitude of decrease was positively correlated with the amounts of heavy metals detected in the soil and the inhibitory effect on turnip was much more pronounced than in lettuce. Furthermore, heavy metals accumulation in soil resulted in an oxidative damage to turnip and lettuce as indicated by the significant increase in lipid peroxidation and H 2 O 2 levels in both plants comparing to control values. The significant increases in putrescine in lettuce and turnip shoots and roots and spermidine in lettuce roots as well as total phenolics and flavonoids in plants cultivated in soil enriched with heavy metals are believed to be defense mechanisms in turnip and lettuce plants to counteract the oxidative stress resulted from heavy metals contamination generated from irrigation with wastewater.
... The amount of biogenic amines in foods is used to indicate the extent of food spoilage. In particular, putrescine and cadaverine can be used as indicators of toxicity in fish (Arnold and Brown, 1978;Mietz and Karmas, 1977). However, the same could not be extrapolated to this study. ...
... The supernatant phase containing the free polyamine fraction was stored frozen. HPLC and fluorescence spectrophotometry were used to separate and quantify the free polyamines according to the method of Mietz and Karmas (1977) and Ayesh et al. (2002). The samples were detected at 254 nm using a standard Spectrophotometer. ...
Irrigation with diluted seawater can act as an alternate water resource and thus plays an important role in saving fresh water resources as well as promoting agriculture. Two pot experiments were conducted to elucidate the effect of foliar application with amino acid mixture (0, 500, 1000 and 1500 mg/L as AA0, AA1, AA2 and AA3, respectively) on faba bean plants irrigated with different seawater levels (0.23, 3.13 and 6.25 dS/m as S0, S1 and S2, respectively) regarding some physiological and biochemical aspects, lipid peroxidation, antioxidant enzymes and endogenous polyamines of faba bean (Vicia faba L.) plants. Irrigation of faba bean plants with different levels of seawater caused significant increases in osmotic solutes (total soluble sugars, free amino acids and proline), phenol content, lipid peroxidation, some antioxidant enzymes (IAA-oxidase, polyphenol oxidase; PPO, peroxidase; POX, super oxide dismutase; SOD, Catalase; CAT, ascorbate peroxidase; APX) and endogenous spermidine and spermine compared with control plants. At the same time, indole acetic acid (IAA), putrescine and total endogenous polyamine contents were decreased in response to different seawater levels. Under salt stress, foliar application with different concentrations stimulated the salt tolerance of faba bean plants via improving osmotic solutes (total soluble sugars, free amino acids and proline), phenolic content, IAA and endogenous polyamines, whereas lipid peroxidation and antioxidant enzymes (PPO, POX, SOD, CAT and APX) were significantly decreased. These results emphasize the potential of application of amino acids mixture in sustainable agriculture in arid and semiarid regions. In addition, it opens up new research lines aimed at obtaining maximum benefit from the amino acids under salinity or other osmotic stress conditions.
Background. Since the beginning of humanity, the global burden of foodborne disease has had a decimating effect on populations, with biogenic amines (BAs) and aflatoxins in meat products implicated. While many developed countries have legitimized safety levels for BAs using evidence-based guidelines to attain high food quality standards for consumers of meat products, developing countries are still battling against poor food quality checking. Purpose. This study examines the level of health risk of biogenic amines and aflatoxin in meat products by extracting and estimating their residues and determining their indices as a way of monitoring the potential health impacts of these residues on consumers of meat products. Methods. A total of 40 imported meat products sampled and randomly collected, representing imported luncheon meat, hot dog sausages, corned beef, and minced meat. Using recommended laboratory protocols, eight residues of BAs and aflatoxins were extracted. Results. Eight BAs, histamine, tyramine, tryptamine, cadaverine, putrescine, β-phenyl ethylamine, spermine, and spermidine, were extracted and determined in all tested samples. Tyramine levels in luncheon meat were found to be significantly higher than in other meat products, while significantly high cadaverine levels were reported in corned beef samples. The results of biogenic amine index (BAI) revealed that the quality of imported minced meat and imported hot dog samples was good (BAI 5 µg/kg) in imported luncheon meat and imported hot dog meat samples. Conclusion. The general results indicate that testing meat products for biogenic amines and aflatoxins is a very good indicator for monitoring the freshness and quality of meat products.
The profile and levels of ten bioactive amines in fresh beef liver was determined and associated with physico-chemical parameters of quality. Furthermore, the influence of refrigerated storage at 0 ± 1 °C and 7 ± 1 °C and of pan-roasting on beef liver quality and safety was investigated. Fresh beef liver was characterized by pH of 6.71-6.92, TVB-N of 98.58-154.72 mg N/100 g and negative H2S. It contained high levels of spermine (up to 119 mg/kg), and low levels of spermidine, putrescine, tyramine and histamine. Therefore, beef liver constitutes one of the richest dietary source of spermine. During refrigerated storage, there were significant physico-chemical changes: the pH decreased, TVB-N increased, and hydrogen sulfide was moderate. The levels of most of the naturally occurring amines increased at rates which were faster at higher storage temperature. Two amines which were not initially detected, reached detectable levels - tryptamine and cadaverine. The proposed bioactive amines based indices of quality to access liver quality were not appropriate to follow gradual quality changes. A shelf life of up to 6 and 4 days during storage at 0 ± 1 °C and 7 ± 1 °C, respectively, is recommended. During pan-roasting at 180 °C for 10 min, the levels of the polyamines increased significantly.
This study investigates biogenic amine development (BA) vs. sensory, chemical and microbiological quality loss of anchovy (Engraulis encrasicolus) at three different chilled storage conditions which are commonly applied for fresh market and/storage prior to processing. The contents of BAs and sensory, chemical and microbiological quality parameters of anchovy were analysed daily during storage. Significant variations occurred (p<0.05) in the sensory, chemical and microbiological values among the storage groups. The highest shelf-life was found as 8 days for samples kept in chilled freshwater. Water-ice mix application resulted in lower TBA content indicating beneficial effect on its quality. Histamine results closely supported sensory values in terms of legally permitted levels set by US Food and Drug Administration (FDA). Histamine forming bacteria counts supported the formation of his-tamine in most groups while total bacteria counts were in agreement with sensory results in terms of acceptability. Moreover, some existing formulated indexes created from various BA levels were not found suitable to estimate spoilage degree of anchovy kept at these conditions. This study suggests that using ice and water-ice mix can improve shelf-life of anchovy stored at refrigerated temperatures in terms of food quality and safety. The results of this study can be used to guide seafood industry for testing fresh anchovy quality and safety at different chilled conditions.
The effects of vacuum packaging followed by E-beam irradiation treatment on the shelf life of common carp (Cyprinus carpio) fillets were studied by measuring biogenic amines and sensory analysis. Samples were irradiated at doses of 0.10, 0.50, 1.0 and 2.0 kGy. Putrescine, cadaverine, histamine and tyramine showed very good correspondence with the irradiation dose and the time of storage. Spermine, spermidine, tryptamine and phenylethylamine did not show statistically significant changes with the time of storage. According to the sensory assessment and biogenic amines index (BAI), the shelf life of unirradiated common carp fillets was found to be approximately seven days. The 1 and 2 kGy irradiation doses extended the shelf life of samples up to 66 and 77 days, respectively. High values of correlation coefficients (r < −0.86) between BAI and sensory evaluation indicated that BAI could be considered as a quality indicator of common carp fillets.
The skin is an epithelial tissue witch prevents microorganisms from entering the chicken body, acting as a protective layer against microbial contamination. it is well known that most of the spoilage bacteria are found on the chicken skin. We studied the initial microbial content of the skin of refrigerated chicken carcasses after slaughter, especially total viable count and psychotrophic count. In the first day of storage we found a total viable count of 5.11 log CFU/cm 2 and psychotrophic count of 4 log CFU/cm 2. Also, we were interested to determine the microbial variation during storage at 4ºC correlated with skin pH. We found that chicken skin pH was steadily increasing during the 21 days of storage at 4ºC, and also the microbial content was increasing. Thus, in the first day of storage total viable count was higher than psychotrophic count with 21.72%, after 14 days of storage the counts were approximately equal and after 21 days of storage the psychotrophic count was higher than total viable count with 0.38%. in chicken skin bioactive amines occur mainly due to enzymatic processes of microbial activity. We studied the presence and variation of following bioactive amines: tryptamine, β-phenylethylamine, putresceine, cadaverine, histamine, serotonin, tyramine, spermidine and spermine in chicken skin during the refrigeration of carcasses. The obtained results indicated that during carcasses storage the content of tryptamine, β-phenylethylamine, putresceine, cadaverine, histamine, serotonin, and tyramine in chicken skin increased. Spermidine and spermine content in chicken skin decreased. Cadaverine was not detected in the first day of storage.
Shrimp paste is an important fermented commodity in the Philippines, but so far their quality parameters are hardly characterized. Paste samples were procured in the province Agusan del Norte, Philippines from three different traditional manufacturers and one from a commercial supermarket. All samples were analyzed for their chemical composition.
Both traditional and commercial shrimp pastes ranged in content of protein (12.9-15.3 g/100 g), fat (0.50-1.94 g/100 g), SAFA (32.6-39.1 g/100 g FAME), MUFA (15.1-18.7 g/100 g FAME), and PUFA (30.7-40.8 g/100 g FAME). The pH value ranged between 6.8-7.7. The samples were microbiological stable due to the low aw -value and high NaCl content, ranging between 0.70-0.74 and 4.04-5.15 g/100 g respectively. Although samples were processed in the same country and under similar conditions, differences were observed for the following parameters: TBARS (2.32-5.03 μgMDA/g), total NPN (3.07-5.15 gN/100 g), free NPN (1.17-2.39 gN/100 g), biogenic amines and mineral content. The Biogenic Amine Index varied between 0 and 976 for the different samples, resulting that only one sample could be considered as class 1 quality.
Results showed that there is a high variation in the quality of the product which could be linked to differences in the fermentation process and hygienic quality.
This article is protected by copyright. All rights reserved.
Fifteen-day-old seedlings of two wheat varieties (Side 1 & Gimmiza 7) were randomly separated into three equal groups to investigate the effect of chilling stress on their antioxidant defense system. Moreover, the possible role of polyamines (PAs) pretreatment during alleviating chilling injuries. The first group was kept in a green house at 21/15°C (day/night) and 10: 14h light/dark (−ve control). Second seedlings group were chilled at 5°C for 6 or 9 hours (+ve control). The Seedlings of the third group were divided into three sub-groups and sprayed with 0.5, 1.0 and 2.0mM spermidine (Spd). After 12 hours of polyamine pre-treatments, the seedlings were incubated at 5°C for 6 or 9 hours. At the end of the chilling period, the treated plants were transferred to the pre-experimental conditions in the greenhouse where they recovered for 10 days. Chilling stress induced a significant increase of lipid peroxidation, membrane leakage and hydrogen peroxide level, while Spd treatments resulted in a significant decrease. In addition, endogenous PA level increased in response to chilling stress. Activities of catalase, peroxidase and ascorbate peroxidase declined after the exposure to chilling whereas glutathione and free ascorbate increased. Spd treatments alleviated the injury caused by chilling stress by preventing the decrease in the activity of the antioxidant enzymes. It can be concluded that the stress protection caused by spermidine treatment probably contributes to the enhancement of the activity of the free-radical scavenging systems. Moreover, it was clear that the Sids-1 cultivar was more tolerant to chilling stress than Gemmieza-7cultivar.
Putrescine and cadaverine are biogenic diamines that are produced during fermentation or spoilage of different food products. Therefore, they are used as indicators to determine food quality. Unfortunately, their chemical analysis is not an easy task. The use of "cold on-column" gas chromatographic (GC) injection together with a new base-deactivated fused silica capillary column is evaluated for the direct GC analysis of putrescine and cadaverine. Multiple injections of standard mixtures containing putrescine, cadaverine, and heptylamine are made in order to determine reproducibility. Standard mixtures at concentrations from 20 to 400 ppm are also injected to determine the linearity of response with both the column and the flame ionization detector. Excellent resolution of the three amines is achieved as well as symmetrical peaks. Multiple injections produce reproducibilities of 1 % for peak areas and 0.03% for retention times. A good linear response is obtained between concentrations of 20 to 400 ppm.
Biogenic amines (BA) are formed by the decarboxilation of the corresponding α-amino acids. Their content in human organism has to be monitored due to their physiological role (hormones, neurotransmitters) in balance with their toxic effects. Wines contain different quantities of biogenic amines depending on the α-amino acid content of grape and the climate of the viticulture area, the vinification process and the hygiene kept throughout the processing. The present paperwork presents the analysis of biogenic amine content (histamine, tyramine, 2-phenylethylamine, putrescine, cadaverine, iso-pentyl-amine) from some Romanian wines produced by three vineyards situated in three different regions with distinct microclimates for grape production.
Changes in the concentrations of biogenic amines (BAs) in fresh beef, pork, and chicken breast and leg were investigated during storage, and the relationship between the content of volatile basic nitrogen (VBN) and BAs was evaluated. As the storage period increased, the levels of putrescine (PUT), cadaverine (CAD) and tyramine (TYM) increased in all the meat samples, except for TYM in beef (p<0.001). The level of BAs in beef, pork and chicken changed but the extent of these changes was different among the kinds of BAs and meats. Measurement of the VBN content was confirmed as a good index for interpreting the specific BAs content in general, such as PUT, CAD, and TYM, as well as evaluating a meat's freshness during storage. However, the kinds of BAs which can be predicted from the VBN content varied in different meats (p<0.05).
Filleting effect of refrigerated bonito with and without ice on the quality changes and food safety was investigated. Significant variations occurred (P P −1. All samples contained acceptable trimethylamine levels for 15 days despite unacceptable sensory values after certain days. Although filleting seemed to increase the lipid oxidation, ice application resulted in lowering thiobarbituric acid content. Histamine results closely supported sensory values in terms of legally permitted levels usually by set FDA. While WBR contained histamine value over EU permitted level as 113.78 ppm on the 7th day, the value for FBRI was 56.13 ppm on the 15th day. Histamine‐forming bacteria counts supported histamine formation in most groups, while total bacteria counts were in agreement with sensory results. This study suggests that using ice and filleting can improve shelf‐life of bonito stored at refrigerated temperatures in terms of food quality and safety.
Biogenic amines are formed as a result of amino acid decarboxylation and are linked to food deterioration. Analysis of these metabolites may be of great importance to determine food quality. The aim of this study was to quantify the biogenic amines (putrescine and cadaverine), and evaluate the physicochemical parameters (pH, ammonia and total volatile bases) of rainbow trout meat (Oncorhynchus mykiss). Fifteen samples were packed in ice and transported in a Styrofoam container to the laboratory. Analyses were performed daily until the 15th day of storage. Biogenic amines concentrations and pH increased signifcantly throughout the storage period. No signifcant differences were observed in total volatile bases values over the time. Ammonia was detected after the 11th day of storage. Based on these results, cadaverine and putrescine may be used as a quality index of rainbow trout; however, total volatile bases may not be adequate parameter for this matrix.
Abstract The freshness of red porgy slaughtered in ice slurry and stored in melting ice was evaluated instrumentally, biochemically and sensorialy. Additionally, postmortem skin colour changes were monitored, in an attempt to demonstrate the use of chromaticity parameters as a reliable and convenient approach to quality assessment. Dielectric properties showed a statistically significant decrease (PL*) and hue (H°ab) at the dorsal skin area were observed on days 1 and 3 following harvesting. Finally, there was a marked decrease in the entire colour index (ECI – a combination of skin hue and chroma) of both the dorsal and the ventral area in day 3 onwards to day 7, as well as a statistically significant correlation between all the estimated freshness indices and ECI. Based on all these, we inferred that the total polyamines (or putrescine to spermidine and spermine ratio) and ECI could be reliable estimators of freshness, at least under the experimental conditions applied.
The variation of six biogenic amines (BAs) and total viable count (TVC) in common carp (Cyprinus carpio) stored in ice with 0, 4 and 8 h delay before icing was evaluated in a period of 4 days. Delayed icing led to significant (p < 0.05) increases in TVC throughout the period of storage and showed a good correlation with BAs content. The obtained data showed that putrescine and cadaverine were predominant in all samples and it was indicated that they could be proper indicators to determine the carp quality. Spermidine and spermine increased slightly toward the end of storage and the levels of dangerous BAs (histamine and tyramine) were under the limit over the period. As a result, it is indicated that delaying time affects on formation of BAs and the effect in samples with 8 h delay was significantly (p < 0.05) more than those with 0 and 4 h delay.
The exposure of wheat plants cv. Giza 168 to high temperature stress (35°C±2) for 4 or 8 hours significantly decreased the growth parameters, the yield components, putrescine (Put), total endogenous polyamines (PAs) contents, total amino acid and total essential amino acid contents, where as, the endogenous spermidine (Spd) and spermine (Spm), ethylene, NH+4, glutamic acid, arginine, proline were increased. Treatment of wheat plants before their exposure to high temperature with arginine or putrescine (1.25 and 2.5 mM) enabled the plants to tolerate the injurious effect induced by high temperature stress via increasing the endogenous Put, Spd, the total PA contents, the content of total amino acids, essential amino acids and the ratio of essential to non-essential amino acids and decreasing the ethylene and NH+4 contents as compared with plants exposed to the high temperature stress or the untreated plants. These effects were much more pronounced by applying 2.5 mM of either arginine or putrescine.
In this study quality attributes (microbial and chemical change) of yellowfin tuna (Thunnus albacares) factors during ice storage were investigated. Production of three biogenic amines (histamine, putrescine, cadaverine) for whole yellowfin tuna (Thunnus albacares) stored in ice on-board of catch vessels, after towing, were also studied. The maximum mean concentration of putrescine, cadaverine and histamine were 23.39 μg/g, 12.37 μg/g and 4.30 μg/g, respectively. During ice storage psychrophilic bacteria became the dominant microbial population of the sample and their number exceeded the maximum permitted limit (107 cfu/g) established by the International Commission of Microbiological Specifications for Foods (ICMSF) (>108 cfu/g in this study). Results showed that putrescine was the main biogenic amine formed and its highest value was 23.39 mg/kg, also the highly correlation showed between putrescine content and psychrophilic bacterial numbers (r 2=0.94). Histamine development was found to be lower than the safety level detrimined by Food and Drug Administration. In this study the mean concentration of putrescine and cadaverine detected in some samples were higher than the acceptable range but most of the fishes stored in the catch vessels with this storage method (ice storage) are still suitable for consumption after towing out.
Monitoring of biogenic amines in food is important for quality control, in terms of freshness evaluation and even more for food safety. A novel and cost-effective method was developed and validated for the determination of the main biogenic amines: histamine, putrescine, cadaverine, spermidine and spermine in fish tissues. The method includes extraction of amines with perchloric acid, pre-column derivatization with Pyrene Sulfonyl Chloride (PSCl), extraction of derivatives with toluene, back-dissolution in ACN after evaporation and determination by reversed phase high performance liquid chromatography with UV and intramolecular excimer fluorescence detection. The structure of the pyrene-derivatives was confirmed by liquid chromatography–mass spectrometry with electrospray ionization. The standard addition technique was applied for the quantitation due to significant matrix effect, while the use of 1,7-diaminoheptane as internal standard offered an additional confirmation tool for the identification of the analytes. Method repeatability expressed as %RSD ranged between 7.4–14% for the different amines and recovery ranged from 67% for histamine up to 114% for spermine. The limits of detection ranged between 0.1–1.4 mg kg−1 and the limits of quantification between 0.3–4.2 mg kg−1. The method was applied to canned fish samples and the concentrations of the individual biogenic amines were below the detection limit up to 40.1 mg kg−1, while their sum was within the range 4.1–49.6 mg kg−1.
This study aimed to investigate the presence of eight biogenic amines (BAs): tryptamine (TRP), phenylethylamine (PHE), putrescine (PUT), cadaverine (CAD), histamine (HIS), tyramine (TYR), spermidine (SPD) and spermine (SPM) in cheese, fish & fishery products and meat & meat products obtained from the Croatian retail market. A selective and robust method of high-performance liquid chromatography (HPLC) with diode array detection (DAD) was applied for the determination of BAs in a total of 91 samples in accordance with the performance criteria outlined in the European legislation. A high inter- and intra-food group variability of the amounts of BAs was observed. In the analysed samples, the most represented amines were TYR, HIS, CAD and PUT. Based on the highest content of the most toxic BAs (HIS and TYR) and consequential food safety concerns, the studied food groups can be ranked in the following order: cheese (HIS up to 106.4 mg/kg; TYR up to 206.6 mg/kg), fish &fishery products (HIS up to 98.8 mg/kg; TYR up to 47.9 mg/kg), and meat & meat products (HIS up to 20.0 mg/kg; TYR up to 117.5 mg/kg). The total BA content was significantly higher (p < .05) in fermented in comparison with other food. The study aimed to contribute to the knowledge on BA toxicity and food quality, as well as to support the indispensable future studies of consumption data and exposure assessment, to the end of defining allowable BA concentrations in food.
In this work, a new methodology for the determination of biogenic amines in cheese is presented, which includes an innovative sample preparation approach based on salting-out assisted liquid-liquid extraction (SALLE). The method features a pre-extraction of the soluble biogenic amines with hydrochloric acid, a derivatization with dansyl chloride, the use of the salting-out effect, and the analysis of the derivatized biogenic amines using high-performance liquid chromatography with fluorescence detection. Several extraction parameters were studied and optimized, such as the HCl extraction time, concentration of the derivatization reagent and influence of the medium’s pH, among others. For the considered biogenic amines, the developed method exhibits adequate limits of detection (0.015 to 1.77 mg L−1) and quantification (0.050 to 5.91 mg L−1) and average recoveries between 94 and 110%, with the highest determined amounts found for putrescine, dimethylamine and histamine. Furthermore, mass spectrometry studies identified and confirmed the presence of several biogenic amines in the samples. SALLE stands as a good alternative to existing methods, since it simplifies the sample preparation step, while improving the overall selectivity of the process. It may also be adopted for the determination of biogenic amines in different solid samples besides cheese, such as meat, fish or other food products.
An ion-pair HPLC method with postcolumn o-phthalaldehyde (OPA) derivatization and fluorescence detection was validated for quantitative determination of five biogenic amines (histamine, tyramine, cadaverine, putrescine, and agmatine) in canned fish products (mackerel, sardine, and tuna) marketed in Ghana. The validated method exhibited excellent selectivity and good linearity (R2 > 0.9990) for all the amines. The limits of detection and quantification for studied biogenic amines were in the range of 0.32–0.78 mg·kg−1 and 1.10–2.57 mg·kg−1, respectively. Also, a satisfactory recovery was obtained for all the amines (82.1–101.4%), and the relative standard deviations were lower than 9.3% under repeatability conditions for the studied amines. Subsequently, the method was applied to the analysis of biogenic amines in canned fish products to estimate the safety of Ghanaian consumers. The maximum levels of histamine, tyramine, cadaverine, putrescine, and agmatine detected in the analysed canned fish products were 64.05 mg·kg−1, 27.44 mg·kg−1, 27.23 mg·kg−1, 18.74 mg·kg−1, and 52.72 mg·kg−1, respectively. Thus, the levels of biogenic amines detected in the canned fish products were lower than the acceptable levels and, therefore, can be considered relatively safe for human consumption.
The influences of nanoemulsions based on citrus peel (orange, lemon, mandarin, and grapefruit) essential oils on the biogenic amine (BA) formation in rainbow trout (Oncorhynchus mykiss) fillets stored 4 ± 2°C were investigated. The results demonstrated that main BAs in the trout fillets were putrescine, cadaverine, spermidine, spermine, serotonin, tyramine, dopamine, and agmatine. It was determined that nanoemulsion application had generally suppressive effect on the formation of BAs during storage. It was also found that especially orange and lemon nanoemulsion groups were effective on histamine formation. Histamine values ranged from 0.00 to 4.08 in all groups during storage and the levels were below the limit values of FDA and EU throughout the storage period for all treatment groups. Similarly, Quality Index (QI) values of BAs were found to be below legal limits in all groups. Consequently, it was found that nanoemulsions prepared from essential oils kept the BA formation at a lower level during storage.
“Plant milks” are water-based beverages, such as, extracts from cereals, pseudo-cereals, oil seeds, legumes or fruits. Plant milk consumption is rising in European and North American markets due to problems related to cow milk allergies, intolerances, but also because of vegan diets and sensitivity to environmental issues. There is no specific regulation for these beverages, therefore their composition can vary considerably, even in the same category. The aim of this study is to characterize the main categories of cereal and pseudo-cereal milks on the market by studying the profile of 8 biogenic amines (histamine, serotonin, spermine, spermidine, putrescine, β-phenylethylamine, cadaverine, tyramine) through a RP-HPLC/FD method with a pre-column derivatization. Biogenic amines are ubiquitous compounds, produced by the decarboxylation of the respective amino acids and they have been proposed as quality and safety markers of different foods and beverages. In the analyzed samples, the total biogenic amines content ranged from a minimum of 1.92 mg/L, to a maximum of 9.27 mg/L. The main biogenic amine found in the samples was histamine. The results show a low content of biogenic amines in all types of analyzed products. This ensures the quality and safety of cereal and pseudo-cereal milk samples.
Heat shock stress causes alteration in the physiological and molecular characteristics in plants due to the generation of reactive oxygen species which cause reduction in plant growth. In this study, four maize hybrids (Sc122, TWC 321, TWC 324 and TWC 352) were grown under normal temperature (25 °C) and after 12 days, a set of the four hybrids with three replicates was exposed to heat shock (45 °C) for 2 h. The results showed on the one hand that heat shock stress caused an increment in phytohormones (auxin, gibberellic acid and zeatin) except abscisic acid in two maize hybrids (Sc122 and TWC 321). On the other hand, all the parameters mentioned above were decreased significantly in the other maize hybrids (TWC 324 and TWC 352). In addition, osmolytes (proline and glycine betaine), polyamines (spermidine, putrescine, and spermine) and total soluble sugars were significantly increased in all maize hybrids but the most pronounced increases were recorded in the two maize hybrids Sc122 and TWC 321. These results confirm a previous study that the maize hybrids Sc122 and TWC 321 are considered as tolerant genotypes and the other two hybrids (TWC 324 and TWC 352) as sensitive genotypes. Differential gene expression under normal and heat shock conditions were adopted to search for some heat responsive genes in Egyptian maize hybrids. Three out of the five designed primers produced fragments. Alignment analysis revealed resemblance of the resulted fragments and some heat responsive genes in different species.
We analyzed the volatile basic nitrogen content, pH, total viable cell count, and biogenic amine contents in chub mackerel (Scomber japonicus) stored at 5 and 25°C to examine changes in freshness. Among the various parameters, we found the volatile basic nitrogen content had the highest correlation with cadaverine content (r2 = 0.72 to 0.88). We also tried to measure cadaverine contents at different times during storage by using near-infrared (NIR) spectroscopy. However, because of the high water content in the fish, we could not obtain meaningful results. Next, we prepared samples for NIR spectroscopy by dilution with 0.1 N HCl, ultrafiltration (3 or 10 kDa) with a glass filter, and dehydration. The samples prepared with the 3-kDa filter had peaks in the NIR spectra between 1,379.3 and 1,388.9 nm, and those prepared with the 10-kDa filter had peaks in the spectra between 1,897.3 and 1,898.6 nm. The correlation coefficient (r2) between the NIR spectroscopy and high-performance liquid chromatography with cadaverine results was 0.98 to 0.99. We concluded that the biogenic amine content could be used to evaluate freshness in fish products, and that NIR measurements could be used to rapidly and accurately determine freshness.
L'étude des réseaux uniformes de Doehlert a conduit à la compréhension des interactions entre les constituants du LP-s et à l'optimisation de leur concentration. A 25°C, la peroxydation du SCN- est augmentée par le glucose et la LPO, et est affectée par les interactions GOD/glucose, GOD/pH et LPO/pH. Le LP-s optimisé avec une concentration initiale en SCN- de 50 mg.I-1 est composé de 85,5 UI.I-1 de GOD, de 1,5 g.I-1 de glucose et de 3930 UI.I-1 de LPO avec un pH initial de 6,5. L'activité inhibitrice de ce LP-s optimisé a été expérimentée sur la croissance de L. monocytogenes DSM 20600T, de B. thermosphacta DSM 20171T, de C. maltaromaticum DSM 20700T et de S. putrefaciens CIP 80.40T en cultures pures et mixtes, à 4°C, en milieu TSB-YE et en milieu modèle poisson créé pour cette étude. En milieu TSB-YE et en cultures pures et mixtes, L. monocytogenes DSM 20600T est la plus affectée par la présence du LP-s. En milieu modèle et en cultures pures, la croissance des quatre souches tests est très affectée par la présence du LP-s. En milieu modèle et en culture mixte, les croissances de S. putrefaciens CIP 80.40T, L. monocytogenes DSM 20600T et B. thermosphacta DSM 20171T sont totalement inhibées; dans ces conditions, le LP-s a un effet uniquement bactériostatique sur la croissance de C. maltaromaticum DSM 207001T
The present research focused on the biogenic amines (BAs) formation in skipjack tuna (Katsuwonus pelamis) throughout the whole canning process. In agreement with its wide employment on this species, on-board brine immersion freezing (BIF) was tested as post-mortem processing. The study included fish samples corresponding to different stages of the canning process such as frozen, thawed, cooked and canned; after cooking, two kinds of tuna muscles were considered, that is, whole fillets (main product) and grated muscle (off-product arising from small pieces). For the BAs (tryptamine, putrescine, cadaverine, histamine, spermidine and spermine) assessment, an HPLC-DAD method was developed and validated in skipjack tuna samples, in agreement with different parameters such as suitability, linearity, limits of detection and quantification, precision, accuracy and robustness. Tuna submitted on-board to BIF procedure provided low levels of spermine and spermidine (up to 27.6 mg kg⁻¹), while contents on the remaining BAs maintained below the limit of detection. Throughout the different stages of the canning process, skipjack tuna showed a low formation of most BAs; interestingly, histamine content was found below 10.6 mg kg⁻¹ level. The highest values were obtained for spermidine, these related to cooked grated tuna (from 22.6 to 66.7 mg kg⁻¹) and canned grated tuna (from 70.6 to 104.4 mg kg⁻¹). Values for pH assessment in all kinds of tuna samples corroborated the results obtained for BAs determination. BIF procedure proved to be an amenable post-mortem processing to guarantee the quality of canned skipjack tuna.
Biogenic amines (BAs) are a group of substances with low molecular weight organic compounds such as aliphatic, aromatic or heterocyclic structures that are naturally present in animal tissues. The aim of this study was to investigate the changes on the formation of biogenic amine, bacterial load and biochemical characteristics in blue swimmer crab (Portunus pelagicus) at different storage temperatures (4 and 20 °C) up to 96 h. From seven BAs only four biogenic amines (tryptamine, putrescine, histamine, and tyramine) were detected while, the cadaverine, spermidine and spermine were absent in all investigated samples. Histamine was the major biogenic amine formed during the storage times and reached the highest concentration of 7.55 ± 0.46 mg/100 g and 17.68 ± 1.30 mg/100 g after 96 h at 4 and 20 °C, respectively. This level of histamine exceeded the maximum tolerance level of 5 mg/100 g. However, the proper icing procedure retarded the histamine effects, resulting only 7.55 mg/100 g after 96 h of ice storage. Spoilage indicator putrescine was only detected after 24–96 h of storage at 4 and 20 °C, respectively. The total volatile base nitrogen and the trimethylamine-nitrogen concentrations were considered to be reliable indicators of freshness index in blue swimmer crab. An aerobic mesophilic plate count of 6.68 and 7.31 log CFU/g were noted for crab stored in ice and ambient temperature after 96 h storage, respectively. It could be concluded that the biogenic amine forming bacteria and other susceptible perishing factors responsible for the biogenic amine formation could be prevented by continuous storage of P. pelagicus at low temperature.
An improved quality benchmarking and shelf life evaluation of freshly harvested black tiger shrimp (penaeus monodon) was pursued by combining sensory and chemical methods. This involved developing a quality index method (QIM) to further assess both freshness and shelf life of the studied shrimp samples. The quality index included the use of trimethylamine (TMA-N), total volatile basis nitrogen (TVB-N), histamine, and hypoxanthine, which were performed at scheduled times during the ten days of ice storage (0°C). Shelf life of the studied shrimp was most likely to be 8 days, and there were positive linear correlations between quality indices (QI) and storage period. The quality of shrimp decreased over storage time. In fact, significant changes of chemical and sensory characteristics of the shrimp samples would become more obvious from day 5 onwards. Besides, quality classification of black tiger shrimp involved four main levels, namely: excellent, good, moderately acceptable, and just acceptable.
The presence of biogenic amines (BAs) is a consequence of specifific free amino acid decarboxylation present in foods of animal origin. If adequate conditions of storage and commercialization are not implemented according to the standards of each product, there is the possibility of bacterial growth, decomposition and formation of these metabolites. Analysis of BAs is important to public heath not only for their relationship with intoxication episodes, but also as useful indicators of food quality. Liquid chromatography with ultraviolet or flfluorescence detection is a more suitable technique to identify and quantify BAs in foods. However, some variations in extraction, derivatization and equipment condition are performed according to the food matrix evaluated (meat, milk, fifish, honey, and others). Due to the current relevance of BAs in the food industry and consumer safety, researchers have tried to develop new analytical methods for fast, reliable analysis of foods in the market. ThThis review presents some of the liquid chromatographic techniques applied to monitoring BAs in different foods of animal origin.
Chitosan coating and plastic wrap coating were investigated for their effects on the quality of grass carp fillets stored at 4±1℃ for a period of 20 days. The fillets were divided into groups of untreated (Control), wrapped with sterile preservative film (PE), and chitosan treated (1%, 2%, 2.5% w/v corresponding to CH1, CH2, CH2.5, respectively). The final result demonstrated that chitosan coating has positive effects on microbial inhibition of total volatile count, lactic acid bacteria, Enterobacteriaceae, Pseudomonas, H2S-producing bacteria (including Shewanella putrefaciens), and Staphylococcus. With regard to the results of biogenic amines, putrescine and histamine were the major amines, and their concentration was significantly (P < 0.05) higher in Control and PE than in chitosan coated fillets at the end of storage. The final concentration in Control, PE, CH1, CH2, and CH2.5 was 143.7, 160.1, 83.0, 59.4, and 44.2 mg/kg for putrescine and 228.0, 57.1, 4.1 3.2, and 2.9 for histamine, respectiv...
This study was carried out to evaluate the quality of the three edible tissues (muscles, hepatopancreas and gonads) of the male and female Chinese mitten crab (Eriocheir sinensis) in natural harvest season, based on total volatile base nitrogen test (TVBN) and biogenic amines analysis at intervals time of 3 h extended for 24 h during 30 °C storage (a mean ambient temperature in harvest season). In addition, the relationship between the value of TVBN and storage time or main biogenic amine was evaluated. Results showed that TVBN level of female gonad reached the recommended limit (30 mg/100 g) at 3 h, and the times of reaching the recommended limit were 15 h in both sexes muscles, while in male and female hepatopancreas reached the recommended limit at times of over 24 and 24 h respectively. Moreover, putrescine was highest in amount in all biogenic amines analyzed. We suggested that TVBN value could be as a good indicator for Chinese mitten crab freshness. According to analysis for biogenic amine accumulated in edible tissues of crab, it was possible that dead crab poisoning may be caused by putrescine. Dead Chinese mitten crabs for over 24 h, should be not recommended for eating or processing.
Biogenic amines (also known as biologically active amines) are low-molecular weight organic compounds produced in biological systems by enzymatic decarboxylation of certain amino acids such as histamine and tyrosine. Examples include dopamine, histamine, norepinephrine, serotonin, and tyramine. They function
in the body as neurotransmitters and relay signals between neurons across synapses to impact on mental functions, blood pressure, body temperature, appetite, and several other physiological processes. The levels of biogenic amines in the body are regulated for proper functioning of the various physiological processes that they are associated with. Certain foods contain biogenic amines that can add to the amounts naturally present in the body. High intake of these foods could upset the balance of biogenic amines in the body to cause health problems such as hypotension, hypertension, gastrointestinal distress, headaches and migraine, and others. Thus, it is crucial to curtail the formation and levels of these compounds in certain food products. This chapter discusses the formation and occurrence of biogenic amines in selected food products, their effects of human health and significance to the food industry, their detection, and their fate during processing and storage. The chapter also covers regulation of biogenic amines in foods.
The biogenic amine contents in fillets of three freshwater fish of kutum (Rutilus frisii), common carp (Cyprinus carpio), and Caspian salmon (Salmon caspius) were monitored during storage at 4°C for 20 days. The amounts of biogenic amines were determined at regular intervals using high performance liquid chromatography after derivatization with benzoyl chloride. Significant differences in the levels of selected biogenic amines among the fish samples were found (P<0.05) during storage times. While the amount of putrescine, cadaverine, histamine, and tyramine in the fish fillets increased during the storage time, the changes in spermine and spermidine contents of the fish species were minor and both showed low and inverse correlations with storage time. For each of the three fish species, the sensory acceptability limit was found to be 4-8 days. The quality and biogenic amine indices of fish samples showed high correlation with storage time (r>0.9). The principal component analysis of the results indicated that the formation of biogenic amines displays a certain behavioral pattern in all fish samples.
The aim of this work was to determine the changes in quality of cooked Southern King Crab (Lithodes santolla) meat during storage at 0°C for 5 and 10 days and -20°C for 10, 30, 60, and 90 days. Chemical indices varied from the initial to the final storage time in refrigerated and frozen samples as follows: TVB-N= 15.8-29.2 mg/100 g and 15.8-23.2 mg/100 g, TMA= 0.0-8.3 mg/100 g and 0.0-1.2 mg/100 g, formaldehyde: 0.5-8.6 mg/kg and 0.5-3.7 mg/kg, indole: 3.3-20.7 µg/100 g and 3.3-6.6 µg/100 g, lactic acid: 16.4-39.1 mg/100 g and 16.4-16.6 mg/100 g, and P-ratio= 0-28.4% and 0-5.2%, respectively. The total nucleotide content rendered 6.77 µmol/g, with adenosine monophosphate (AMP) the main component. The nucleotide indices varied in refrigerated and frozen samples as follows: K= 7.37-27.5% and 7.37-10.3%, Ki= 58.3-86.5% and 58.3-82.7%, H= 30.2-54.9% and 30.2-38.0%, G= 19.4-57.8% and 19.4-15.8%, P= 17.2-42.3% and 17.2-14.7%, and Fr= 41.6-13.4% and 41.6-17.3%, respectively. Biogenic amines found at both storage temperatures were spermine, spermidine, tyramine, and agmatine. Spermine may be considered as a potential freshness index for refrigerated samples and spermidine for frozen storage. Tyramine level should be monitored. During the storage period tested, none of the chemical indices studied exceeded the legal limits.
The grains of Oryza sativa L. Sakha 101 cultivar (salt tolerant) were irradiated with 0.0, 5, 10 and 15 KR of gamma rays and their mature embryo-derived calli were exposed to different levels of drought-stress, in order to reveal the bases of physiological behavior of in-vitro cultured rice under gamma-irradiation or drought-stress. The effect of pre-treatment with gamma-irradiation on the response of rice to drought was also evaluated. The results showed that treatment with PEG highly significantly reduced the fresh and dry weight of the most investigated rice calli. However, the magnitude of loss was much less in the irradiated calli than the non-irradiated ones. For each increase in PEG-stress level there was a concomitant increase in total soluble sugars content of both the non-irradiated and irradiated samples. However, most of the irradiated calli exhibited higher tendency to accumulate soluble sugars than the non-irradiated ones in response to higher PEG concentrations. Though diminishing the content of most mineral elements by PEG, the irradiated cells could keep more of their phosphorus, K + , Ca 2+ and Mg 2+ than the non-irradiated ones. Polyamines (PAs) accumulated in rice calli under drought or radiation-stress. Accumulation of Put and Spd was higher than Spm in response to radiation-stress, while that of Spd and Spm was higher than Put in response to drought. While drought stress caused the disappearance of the 78 and 45 kDa polypeptides, radiation increased their expression. The 93 and 30 kDa polypeptides were expressed only under drought stress either with or without irradiation. The 69 and 60 kDa polypeptides were intensified in response to both radiation and PEG. It was concluded that the pre-exposure to gamma-irradiation had alleviated the harmful effect of drought on rice calli.
Fish as Food; Production, Biochemistry and Microbiology
Chemical compounds formed during the spoilage of fish
The spoilage of fish and its preservation by chilling
Simple test for the degree of putrefaction of raw fish
A review of the value of volatile reducing substances for the chemical assessment of the freshness of fish and fish products
Symposium on Foods: The Chemistry and Physiology of Flavors
Chemical changes that occur in the proteins, nucleotides, and lipids of fish tissue during storage at low temperatures were investigated. Homogenized tissue, prepared from fresh rock-fish (striped hass, Roccus species), was stored up to six days at temperatures from -10° to 4°C and then analyzed. At 0°C and below, the solubility of myofibrillar proteins decreased. There were also changes in polyacrylamide gel electrophoretic patterns of protein extracts. The total nucleotide content decreased rapidly at all temperatures. The lipids were extracted from each sample and separated into neutral lipids, phospholipids, and free fatty acids by column chromatography. The fatty acid composition of each fraction was determined by gas chromatography. In the fresh tissue, polyunsaturated acids occurred in greatest proportion in the free fatty acid and phospholipid fractions, whereas inono-unsaturated acids were inofe highly concentrated in the neutral lipids. The percentages of saturated acids were approximately the same in all fractions. During storage, there were considerably larger losses of individual acids from phospholipids than from neutral lipids. The polyunsaturated acids of the phospholipid fraction were affected most. Over 10% of these aeids were lost in six days at ice temperature, but only a small proportion of the losses was accounted for by increases in free fatty acids. Oxidative proo esses may account for the imbalance because the rate of oxidation, as measured by the thio-barbituric acid test, increased with storage temperature in the same manner as the rale at which unsaturated fatty acids were lost from the pliospliolipuls. Losses of polyunsaturated acids from the neutral lipids were much smaller, suggesting a selectively protective mechanism or environment in that fraction. The changes in the phospholipid fatty acids may provide the basis for useful objective tests of fish lecomposilion.
Amines, extracted from tissues of sablefish (Anoplopoma fimbria), coho salmon (Oncorhynchus kisutch), and salmon roe (genus, Oncorhynchus), were analyzed by gas chromatography, and also by thinlayer chromatography-spectrophptofluorometry of the corresponding 5-dimethylamino-l-naphthalene-sulfonamides. The data provide evidence for the presence of dimethylamine in long-stored frozen salmon flesh and its absence in sablefish flesh above a detection limit of 7 ng/g wet tissue. The methyl-amines and diethylamine were the only amines confirmed at levels above the limits of detection.
The basic constituents of a highly volatile fraction collected during molecular distillation of menhaden oil have been examined by paper chromatography and thin-layer chromatography. Tentatively identified were ethylenediamine and 1,4-butanediamine as major components with smaller amounts of propyl- and hexylamines. Secondary and tertiary amines or quaternary ammonium bases were not detected.
The hypoxanthine contents of fresh fillets taken from three species of fish in Pacific Northwest waters were found to he almost zero, and increased at a fairly uniform rate during the first 8-10 days of storage in melting ice. The hypoxanthine content reached maximum values in about 8-10 days. Total nucleotides reached a minimum in about 6-8 days. Fillets stored at −20°F showed practically no change in hypoxanthine content during four, months of storage.
Hypoxanthine can be rapidly measured and the data can be used to judge the length of time fish has been held in storage.
Gas chromatography on an alkaline Dowfax 9N9 column has been found to be suitable for the qualitative and quantitative analysis of alkylamines in dilute aqueous solution. The method has been applied to the analysis of trimethylamine (TMA) and dimethylamine (DMA) in fish and has been used to throw further light on uncertainties concerning the use of the “picrate” procedure for TMA determination.
Rapid estimates of hypoxanthine concentration in muscle extracts by xanthine oxidase reaction agreed well with those obtained by ion-exchange chromatography. Assay by precipitation as the silver salt was subject to some inaccuracy. Concentrations of hypoxanthine increased throughout the period of useful storage of a number of species. The increases correlated well with most evaluations of quality by taste panel.
Studies have been made on the extractives and volatile substances (amino-acids, amines and other nitrogenous compounds, sugars, etc.) of freshly caught cod muscle and of some of the changes that occur during autolysis (storage at 0° under sterile conditions) alone or combined with bacterial spoilage as in normal trade practice (storage in ice). The merits of some of these changes as objective indices of quality, particularly in relation to taste panel assessment, are discussed.
The concentration of a number of amines was determined in fresh and processed pork bellies. Analyses were conducted for spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine, and ethanolamine. Fresh, pickled, and fully cured and smoked bellies were obtained from two commercial sources. The amines were recovered from perchloric acid extracts of the lean meat and derivatized with dansyl chloride. The fluorescent derivatives were separated by thin-layer chromatography, extracted, and then quantitated spectrofluorometrically. The concentration per 100 g of tissue ranged from 0.03 mg for cadaverine to 8.1 mg for spermine. There were considerable variations in the levels of the individual amines within different specimens of the same sample. Processing did not significantly alter the levels of the free amines.
The stability of fish lipids during storage of fish tissue at ice temperature was investigated. Homogenized tissue from rockfish (striped bass, Roccus species) was stored 16 days at melting ice temperature. Lipids were extracted at intervals and separated into various components by silicic acid column chromatography. Changes in the weights of individual lipid components were correlated with gas chromatographic data on changes in individual acids of these components. In the fresh tissue, the phospholipid fraction contained the highest proportion of polyunsaturated acids and the neutral lipid fraction contained the highest proportion of monounsaturated acids. During storage of the tissue, there were decreases in the weights of total phospholipids and neutral lipids and an almost equivalent increase in the amount of free fatty acids. Although there were changes in all acids during storage, the polyunsaturated acids, eicosapentaenoic (C20:5) and docosahexaenoic (C22:6), were affected most and were lost at a faster rate from phospholipids than from neutral lipids. The loss of polyunsaturated acids was apparently by a selective process because most of the loss was from the cephalin fraction, even though it contained only about ¼ of the total polyunsaturated acids. Relatively small amounts of these acids were lost from the neutral lipids and virtually none from the lecithin.
IN earlier papers1,2 we have reported studies on the changes in acid-soluble nucleotides of carp muscle in which they found the accumulation of inosinic acid as a result of slow freezing. Further, the changes of these compounds with time in red lateral and in dorsal muscle of rainbow trout were followed by using ion-exchange chromatography. It was found that the enzyme activities of the former affecting the breakdown of nucleotides are greater than of the latter.