Global occurrence of aflatoxin M1 in milk with particular reference to Iran

Aflatoxin M₁ (AFM₁) is an hydroxylated derivative of aflatoxin B₁ (AFB₁), which occurs in the milk of lactating animals. The aim of the present study was to determine the concentrations of AFM₁ in raw milk samples collected from 18 dairy farms in Qazvin, Iran, over a period of 1 year and compare them with those found in other countries. Samples (30 per farm) were collected in the four seasons, Spring, Summer, Autumn and Winter occurring between April 2009 and March 2010, giving a total of 2160 samples. They were centrifuged and 100 μl of the resulting skimmed milk were tested for AFM₁ contamination by competitive enzyme immunoassay (EIA). All samples (100 %) were contaminated with AFM₁ with concentrations ranging from 0.04 to 148.01 ng.l^?1 and a mean of 38.82 ng.l^?1. Summer samples with a mean of 64.69 ng.l^?1 and autumn samples with a mean of 0.14 ng.l^?1 had the highest and lowest concentrations, respectively, and differed significantly (P?<?0.05). AFM₁ content in 722 samples (33.4 %) was higher than the maximum tolerance limit of 50 ng.l^?1 accepted by the European Union (EU). As contamination of milk with AFM₁ is a potential risk for human health, raw milk should be monitored for its presence.     

Assessment of aflatoxin M1 levels in selected dairy products in north‐western Iran

The purpose of this survey was to evaluate the natural occurrence and content of aflatoxin M_1, AFM_1, in dairy products marketed in Urmia. During September 2007, 40 samples of pasteurised milk, 40 samples of ultra high temperature‐treated (UHT) milk, 40 samples of creamy cheese and 40 samples of Iranian Feta cheese were collected from different supermarkets in Urmia city. AFM₁ contents were determined by the competitive enzyme‐linked imunosorbent assay (ELISA) technique. All milk samples analysed showed a mean of AFM₁ concentrations lower than the permissible level of 50 ng/kg in Iran (23.22 and 19.53 ng/kg in pasteurised milk and UHT milk respectively). The mean levels of AFM₁ contamination were 43.31 ng/kg in Feta cheeses and 21.96 ng/kg in creamy cheeses. The potential risk of human exposure to aflatoxin M₁ via consumption of milk and milk products is well known. Dairy products must therefore be evaluated for aflatoxin and kept free from fungal contamination as much as possible.     

Composition and occurrence of aflatoxin M1 in cow's milk samples from Razavi Khorasan Province,Iran

The composition and occurrence of aflatoxin M₁ (AFM₁) were investigated in 60 samples of cow's raw milk samples from Razavi Khorasan Province of Iran. Only percentages of milk samples protein, lactose and total solids in samples collected during summer were slightly lower than the Iranian reference values. Compared with summer samples, higher percentages of milk samples components were observed in the winter. The overall mean AFM₁ level was 61 ± 8 ng/L, with 24 samples (40%) showing concentrations above the maximum permitted level established in Iran (50 ng/L). Control measures are urgently needed to avoid aflatoxin in milk samples produced in Razavi Khorasan Province.     

Occurrence of Aflatoxins and Ochratoxin A in Baby Foods in Portugal

Infants have a more restricted diet and they generally consume more food on a body weight basis than adults. Therefore, the significance and potential health risk of any contaminant in foods consumed by infants is increased and diligent attention must be paid to this particular area. The present study aims to determine the occurrence of aflatoxin M₁ (AFM₁), aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) in processed cereal-based foods (flours) and infant formulae (milk powder) available in the Portuguese market, both sold as conventional and organic origin. Mycotoxin determination was carried out using a method previously applied to duplicate diet samples. This method employed chloroform extraction, liquid–liquid extraction, immunoaffinity column (IAC) cleanup and HPLC analysis with fluorescence detection after post-column derivatisation. Quantification limits were 0.014, 0.004 and 0.028 μg kg⁻¹ for AFM₁, AFB₁ and OTA, respectively. These toxins could only be quantified in 12 of 27 analysed samples (15 positive results): two samples with AFM₁, two samples with AFM₁ and OTA, one sample with AFB₁ and OTA and seven samples with OTA. Positive results concerned four for AFM₁ (26%), one for AFB₁ (7%) and ten for OTA (67%). For these samples, contents ranged between 0.017–0.041 μg AFM₁ kg⁻¹, 0.034–0.212 μg OTA kg⁻¹, and one sample had a value of 0.009 μg AFB₁ kg⁻¹. Considering the presented results, we could provisionally conclude that the presence of these mycotoxins in baby foods does not constitute a public health problem. These are the first results concerning the occurrence of mycotoxins in marketed baby foods in Portugal and this is the first study using the HPLC method, proposed for duplicate diets, in baby food sample analysis.     

Detection of aflatoxin M1 in milk,cheese and sour cream samples from Costa Rica using enzyme-assisted extraction and HPLC

Aflatoxins are toxic fungal metabolites, which can be found in feed. Aflatoxin M₁ (AFM₁) is excreted into milk when ruminants ingest aflatoxin B₁ contaminated feedstuffs. Due to its carcinogenic potential, contamination of milk and dairy products with AFM₁ may pose a risk for consumers. Hence, it is considered a public health concern. In this survey, the level of AFM₁ contamination of dairy products marketed in Costa Rica was determined by enzyme-assisted extraction, immunoaffinity clean-up and high-performance liquid chromatography coupled with a fluorescent detector (HPLC-FLD) in fluid milk (n = 70), fresh cheese (n = 70) and sour cream (n = 70) collected at local convenience stores and supermarkets. AFM₁ concentrations in milk and fresh cheese ranged from 19 to 629 ng/L and from 31 to 276 ng/L, with mean values of 136 ng/L and 74 ng/L, respectively, whereas none of the sour cream samples analysed tested positive for this aflatoxin. In 30 milk samples, and 10 cheese samples, AFM₁ concentrations surpassed threshold concentrations as established by the European Commission. Thus, sour cream and – to a lesser extent – cheese manufacturing seems to reduce the amount of AFM₁ present in milk, possibly due to fraction redistribution or microbiological degradation. The survey results reveal improper quality control procedures in the Costa Rican dairy industry. Therefore, a surveillance programme for dairy products in our country is recommended.     

Effects of nitrates and nitrites on Lactobacillus helveticus and Lactobacillus casei dairy cultures

 The aim of this work was to observe the effects of nitrites and nitrates on the titratable acidity of milk after addition of Lactobacillus helveticus (TX 121) and L. casei (CAD 154) dairy cultures and on the levels of nitrate and nitrite. After adding L. helveticus and nitrites the increasing concentrations of the latter brought about a marked decrease in titratable acidity. In milk containing 100 mg·kg^–1 nitrite the resulting concentration was 39.33 mg·kg^–1 NaNO₂. Nitrates caused a less obvious decrease in titratable acidity, giving 13.27 g·l^–1 lactic acid. In milk containing 100 mg·kg^–1 NaNO₃ the resulting concentration was 24.99 mg·kg^–1 NaNO₃. Experiments with L. casei and a nitrite additive revealed a decrease in titratable acidity to 8.89 g·l^–1 lactic acid. After incubation, nitrite levels were reduced from 100 mg·kg^–1 NaNO₂ to 37.81 mg·kg^–1 NaNO₂. Nitrates were also stated to inhibit the titratable acidity of the sample, which decreased to 11.42 g·l^–1 lactic acid. Nitrates were reduced to 46.99 mg·kg^–1 NaNO₃. The present study shows that nitrites, more than nitrates decrease the titratable acidity of milk after addition of L. helveticus and L. casei dairy cultures. A reduction of nitrates and nitrites in milk samples by Lactobacillus was also found. The results of this study can be used in the dairy industry in the production of several types of hard cheese as well as fermented milk products that use L. helveticus and L. casei dairy cultures. Received: 31 March 1999 / Revised version: 6 September 1999     

OCCURRENCE OF AFLATOXIN M1 IN RAW MILK DURING THE SUMMER AND WINTER SEASONS IN HAMEDAN, IRAN

A survey on the occurrence of aflatoxin M₁ (AFM₁) was carried out in summer and winter in raw milk samples from 93 traditional and industrial dairy farms of the Hamedan district in order to address representative data on AFM₁ in milk collected from these regions. Of the 186 milk samples, AFM₁ was detected in 119 samples (63.97%). The mean concentration of AFM₁ in contaminated samples was 43.4 ng/L, and the minimum and maximum levels were ≤10 and 410 ng/L, respectively. Fourteen (11.76%) contaminated samples had AFM₁ in concentrations in excess of the maximum levels specified in European Union regulations, i.e., 50 ng/L. The contamination ratio of milk in summer and winter months was 56.5 and 71.7%, respectively (P < 0.02). This is the first report on AFM₁ determinations in raw milk from western Iran, one of the main milk‐production areas, as well as comparison between milk obtained from different dairy farms in Iran.     

Aflatoxins in dairy cow feed,raw milk and milk products from Turkey

This study aims to detect aflatoxins (AFs) in dairy cow feed, milk and milk products using a high-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method. All the validation parameters met the method performance criteria of the European Union. The samples comprised 76 dairy cow feeds and 205 milk and milk products (including yoghurt and yoghurt-based beverage, ayran). AFs were present in 26.3% of the feed samples. Two feed samples exceeded the maximum limit (ML) of 5 µg kg^?1 for AFB₁ as established by the EU. Nineteen milk samples (21.1%) contained aflatoxin M₁ (AFM₁) of which three exceeded the EU ML of 0.05 µg l^?1. In addition, only two yoghurt samples and one ayran sample contained AFM₁, but the levels were lower than the EU ML.     

Determination of Melamine in Liquid Milk and Milk Powder by Titania-Based Ligand-Exchange Hydrophilic Interaction Liquid Chromatography

A simple and rapid high-performance liquid chromatography (HPLC) procedure for the analysis of melamine in liquid milk and milk powder has been developed. Decrease of acetonitrile percentage and phosphate buffer concentration in mobile phase, and lowering of buffer pH and column temperature would benefit the retention of melamine on titania. Taking advantage of the ligand-exchange and hydrophilic interaction mixed retention mode on bare titania column, neither complex pretreatment nor ion-pair reagent was required. The whole analysis for one sample including sample pretreatment and HPLC analysis could be accomplished within 30 min. The method presented good linearity (R ² = 0.9998) in a wide range of 0.02–10 μg mL⁻¹. The limit of detection (3σ) and limit of quantification (10σ) of the method were 6 and 20 μg L⁻¹, respectively, which were equivalent to 15 and 50 μg kg⁻¹ melamine in liquid milk, 60 and 200 μg kg⁻¹ melamine in milk powder, respectively. Such sensitivity could be compared with those obtained by HPLC with solid-phase extraction or HPLC coupled with tandem mass spectrometry and was adequate for the screening of melamine in tainted dairy products. The repeatability (RSDs) of the retention times and peak areas of 11 replicate detections of 1.0 μg mL⁻¹ melamine were 0.32% and 2.5%, respectively. The intermediate precision on three consecutive days (RSDs, n = 6) of the retention times and peak areas were 1.1% and 2.3%, respectively. The recovery of spiked melamine in dairy samples ranged from 95.2% to 105%. The simplicity, sensitivity and rapidity of the proposed method make it an effective alternative detecting technique for melamine.     

Optimization and Modeling of Process Parameters for Lipase Production by Bacillus brevis

Statistical evaluation of fermentation conditions and nutritional factors by Plackett–Burman two-level factorial design followed by optimization of significant parameters using response surface methodology for lipase production by Bacillus brevis was performed in submerged batch fermentation. Temperature, glucose, and olive oil were found to be the significant factors affecting lipase production. Maximum lipase activity of 5.1 U ml⁻¹ and cell mass of 1.82 g l⁻¹ at 32 h were obtained at the optimized conditions of temperature, 33.7 °C; initial pH, 8; and speed of agitation, 100 rpm, with the medium components: olive oil, 13.73 ml l⁻¹; glucose, 13.98 g l⁻¹; peptone, 2 g l⁻¹; Tween 80, 5 ml l⁻¹; NaCl, 5 g l⁻¹; CH₃COONa, 5 g l⁻¹; KCl, 2 g l⁻¹; CaCl₂·2H₂O, 1 g l⁻¹; MnSO₄·H₂O, 0.5 g l⁻¹; FeSO₄·7H₂O, 0.1 g l⁻¹; and MgSO₄·7H₂O, 0.01 g l⁻¹. The lipase productivity and specific lipase activity were found to be 0.106 U (ml h)⁻¹ and 2.55 U mg⁻¹, respectively. Unstructured kinetic models and artificial neural network models were used to describe the lipase fermentation. The kinetic analysis of the lipase fermentation by B. brevis shows that lipase is a growth-associated product.     

A promising innovative technique for mycotoxin detoxification from beverages using biofilms of lactic acid bacteria

This study assessed the removal of aflatoxin M₁ (AFM₁) and ochratoxin A (OTA) from artificially contaminated whole UHT milk and red grape juice, respectively, using biofilms from Lactobacillus rhamnosus GG. Using ELISA, the level of AFM₁ and OTA removal from beverages was determined depending on various factors. Biofilms of various ages demonstrated varying degrees of AFM₁ removal capacity from phosphate-buffered saline (PBS). Different levels of AFM₁ contaminated whole UHT milk (0.1, 0.2, and 1 μg/L) and OTA contaminated red grape juice (2 and 4 μg/L) were tested in the detoxification process. The binding ability of mycotoxins was improved by increasing the biofilm surface area up to 70 cm². L. rhamnosus GG biofilm was effective in removing mycotoxins within a short contact time ranging from 1 to 10 min. The proportion of bound AFM₁ and OTA by L. rhamnosus GG biofilm was 64.6 and 98.3% respectively. A new machine has been proposed and used as a trial for detoxication purposes which would be a promising application in liquid food industries.     

Total Mercury, Inorganic Mercury and Methyl Mercury Determination in Red Wine

This study deals with the development of a method for total Hg, inorganic Hg and methylmercury (MeHg) determination in red wine by using flow injection-cold vapour generation–inductively coupled plasma mass spectrometry (FI-CVG-ICP-MS) and gas chromatography-ICP-MS (GC-ICP-MS). For Hg speciation analysis, a derivatization step was carried out using a 1% (m/v) sodium tetraphenylborate (NaBPh₄) solution, followed by extraction of Hg species and their quantification by GC-ICP-MS. The main parameters evaluated were the make-up gas flow rate, volume of the NaBPh₄ solution, time for derivatization reaction/analyte extraction and solvent used for Hg species extraction. Accuracy was evaluated by analyte recovery, whereas recoveries ranged from 99% to 104% for Hg(II) and MeHg. The limits of detection (LODs) for Hg(II) and MeHg were 0.77 and 0.80 μg L⁻¹, respectively. Wine from Argentina, Brazil, Chile and Uruguay were analysed. The wine samples were also acid digested for total Hg determination by FI-CVG-ICP-MS. The LOD of the method used for total Hg determination was 0.01 μg L⁻¹. The concentrations of Hg species in red wine measured by GC-ICP-MS were lower than the respective LODs. Only total Hg was detected in the analysed samples, where the highest concentration of Hg found was 0.55 ± 0.02 μg L⁻¹.     

Concentrations of cadmium and lead in different types of milk

 Concentrations of Pb and Cd were determined in samples of human, raw and pasteurized cow's and goat's milk and powdered infant formula. The following mean Cd concentrations (and ranges) were recorded: in human milk, 2.70 μg/l (0.6–11.3, n=55); in raw cow's milk, 4.88 μg/l (0.7–23.1, n=47); in pasteurized cow's milk, 4.30 μg/l (3.4–5.9, n=6); in goat's milk, 7.81 μg/l (1.0–18.4, n=38); and in powdered, infant formula, 3.81 μg/l (3.4–4.1, n=5). The concentrations (and ranges) of Pb were: in human milk, 8.34 μg/l (0.1–32.3, n=55); in raw cow's milk, 14.82 μg/l (1.3–39.1, n=28); in pasteurized cow's milk, 10.25 μg/l (6.9–19.6, n=6); in goat's milk, 11.86 μg/l (0.4–38.5, n=36); and in powdered, infant formula, 8.30 μg/l (5.1–10.6, n=5). Our data were within the normal ranges for each kind of milk. The Cd and Pb concentrations in goat's milk were significantly higher than the concentrations observed in the other milks, whereas human milk and powdered infant formula presented the lowest Cd and Pb concentrations. A considerable decrease in the concentration of Cd with the stage of lactation was observed. The concentrations of Cd and Pb in human, cow's and goat's milk also varied according to the time of year. The concentrations of Pb and Cd in the different milks did not present any risk to human health (infants or adults). Received: 26 May 1998     

Determination of Histamine in Some Foods by Isotachophoretic Method with Simple Sample Preparation

A one-dimensional capillary isotachophoretic method in cationic system of the separation has been applied for histamine determination in food samples. The proposed electrolyte system consisted of 0.01 M potassium hydroxide with l-valine to pH = 9.9 as the leading electrolyte and 0.02 M 2-amino-2-hydroxymethyl-propane-1,3-diol adjusted to pH = 8.3 with 0.1 M hydrochloric acid as terminating electrolyte. Proposed method was characterized by linearity range 5–50 mg L⁻¹ and R ² = 0.9982, accuracy (recoveries ranged from 95% to 102%), detection (2.10 mg L⁻¹), and quantification (7.01 mg L⁻¹) limits. The sample preparation for proposed electrophoretic method included only simple extraction with trichloroacetic acid with filtration and derivatisation stage are avoided. The histamine concentration was determined in meat (turkey, chicken, beef and pork) and meat products (ripened sausage and dry-cured ham), fish (smoked salmon and mackerel), and different kind of mildew and mold ripened cheeses samples. The histamine content ranged from not detected level for fresh meat to 29.63 mg 100 g⁻¹ for cheese samples. The reversed phase HPLC was applied as reference method and the F-Snedecor test and the t test were employed to compare the precision and accuracy of the both methods. Positive correlations were found between the two analytical methods for histamine determination in food products. The obtained results indicate that the proposed electrophoretic method is simple, precise, accurate, and convenient.     

Electrochemical Determination of Phenothrin in Agricultural Formulations, Vegetables, and Storage Bags of Wheat and Rice by Differential Pulse Adsorptive Stripping Voltammetry (DP-AdSV)

An electroanalytical method has been developed for the determination of the pesticide phenothrin by differential pulse adsorptive stripping voltammetry on a hanging mercury drop electrode in universal buffer as supporting electrolyte. The best adsorption conditions were found to be pH 6.0, an accumulation potential of −0.6 V, and an accumulation time of 75 s. Effects of stirring rate, scan rate, pulse amplitude, and purge time were examined for the optimization of instrumental conditions. Calibration curve is linear in the range 2 × 10⁻⁹ to 2 × 10⁻⁷ mol l⁻¹ with a detection limit of 1.9 × 10⁻¹⁰ mol l⁻¹. The correlation coefficient and relative standard deviation were 0.995% and 1.1%. The method is applied to the determination of the phenothrin in agricultural formulations, vegetables, and storage bags of wheat and rice under Food Corporation of India’s storage system.     

Screening of Fluoroquinolone Residues in Caprine Milk Using a 5-kg Luminescence Photometer

Fluoroquinolone (FQ) residues in caprine milk were screened by terbium-sensitized luminescence (TSL). After extraction and cleanup using Oasis HLB columns, TSL was measured at λ _ex = 300 nm and λ _em = 546 nm using a 5-kg luminescence photometer. A common threshold was established at x _F50–3σ _F50, where x _F50 and σ _F50 were the mean and standard deviation, respectively, of TSL intensities of milk samples (n = 18) spiked with flumequine at 50 ng/g, its maximum residue limits (MRL) set by the European Union. Enrofloxacin, ciprofloxacin, and danofloxacin at their respective MRLs had higher TSL responses, so could be screened below their MRLs. Among 48 blind samples, each randomly spiked with one FQ at up to 200% of its MRL, 36 were screened correctly without false negative. This rapid protocol can reduce a sample pool to a small fraction for confirmation, hence improve throughput and save assay costs.     

Analytical Methods for the Evaluation of α-<Emphasis Type="SmallCaps">l</Emphasis>-Fucosidase Activity in Sheep Milk

The lack of analytical methods for measuring the activity of highly thermolable endogenous enzymes in sheep milk is a factor that hampers the protection of typical Protected Designation of Origin (PDO) dairy products made from raw milk. In order to provide a solution, this study assesses, tests, and fully validates analytical procedures for the determination of α-l-fucosidase activity in sheep milk. While the UV–VIS method has been optimized for this matrix in order to solve clarification problems before the spectrophotometric reading, a reversed phase high-performance liquid chromatography literature method proposed for bovine milk has been successfully applied also to sheep milk. Both methods have been fully validated in terms of sensitivity, linearity, precision, and accuracy, displaying low detection and quantification limits, excellent linearity over a wide enzymatic activity interval, very good repeatability and reproducibility, and the lack of any bias. The analysis of a number of real samples of whole sheep milk has allowed the evaluation of an average value (46.78 ± 5.49 U mL⁻¹) and range (from 29.27 ± 2.60 to 72.64 ± 1.17 U mL⁻¹) of α-l-fucosidase activity. Such activity does not seem to differ substantially from those measured for bovine milk. Finally, marked seasonal variability has been observed in this preliminary dataset.     

Aflatoxin M1 contamination in cow and buffalo milk samples from the North West Frontier Province (NWFP) and Punjab provinces of Pakistan

A total of 178 milk samples (94 of buffalo and 84 of cow) were randomly taken from Punjab and the North West Frontier Province (NWFP) of Pakistan (n?=?89 in each province) and analysed for the presence of aflatoxin M1 (AFM₁) by HPLC-FLD. From Punjab about 46% of buffalo's and 49% of cow's milks were contaminated with AFM₁ as compared with 52% and 51% for milk samples from NWFP, respectively. Overall, the mean AFM₁ concentration was 0.046?µg?kg^?1 with a maximum of 0.350?µg?kg^?1. All samples complied with the Codex Alimentarius limit of 0.50?µg?kg^?1 for AFM₁ in milk, but 16.3% of samples exceeded the European Union maximum level of 0.05?µg?kg^?1. Another set of 415 buffalo's and cow's milk samples (213 morning milks and 202 evening milks) were analysed. Statistical analysis revealed significant differences (p?<?0.05) between mean AFM₁ concentrations in milk during the morning (0.043?µg?kg^?1) and the evening (0.028?µg?kg^?1) lactation times.     

Aflatoxin M1 in raw milk and aflatoxin B1 in feed from household cows in Singida,Tanzania

Aflatoxin M₁ (AFM₁) contamination in raw milk from household cows fed with sunflower seedcakes or sunflower-based seedcake feeds was determined in 37 milk samples collected randomly from different locations in Singida region, Tanzania. Aflatoxin B₁ (AFB₁) contamination in sunflower-based seedcake feed was determined in 20 feed samples collected from the same household dairy farmers. The samples were analysed by RP-HPLC using fluorescent detection after immunoaffinity column clean-up. Recoveries were 88.0% and 94.5%, while the limits of detection (LOD) were 0.026 ng mL^?1 and 0.364 ng g^?1 for AFM₁ and AFB₁, respectively. Of the analysed cow’s milk samples, 83.8% (31/37) contained AFM₁, with levels ranging from LOD to 2.007 ng mL^?1, exceeding both the European Commission (EC) and Tanzania Food and Drug Authority (TFDA) limit of 0.05 ng mL^?1. Of the contaminated samples, 16.1% exceeded the Codex Alimentarius limit of 0.5 ng mL^?1. AFB₁ was present in 65% (13/20) of the feed samples with levels ranging from LOD to 20.47 ng g^?1, 61.53% exceeding the TFDA and EC maximum limits of 5 ng g^?1 for complete dairy animal feed. The observed AFM₁ and AFB₁ contamination necessitates the need to raise awareness to dairy farmers in Tanzania to safeguard the health of the end-users.     

Stability and Degradation Kinetics of Bioactive Compounds and Colour in Strawberry Jam during Storage

The effect of storage time and temperature on degradation of bioactive compounds such as ascorbic acid, anthocyanins, total phenols, colour and total antioxidant capacity of strawberry jam were investigated. The results indicated that lightness (L) value decreased significantly (p < 0.05) over 28 days of storage at 4 and 15 °C, with lower values measured at higher temperatures. Anthocyanins, ascorbic acid and colour degradation followed first-order kinetics where the rate constant increased with an increase in the temperature. The reaction rate constant (k) increased from 0.95 × 10⁻² day⁻¹ to 1.71 × 10⁻² day⁻¹ at 4 and 15 °C for anthocyanins. Similarly, k increased from 2.08 × 10⁻² day⁻¹ to 4.54 × 10⁻² day⁻¹ at 4 and 15 °C for ascorbic acid. In general, total antioxidant activity for strawberry jam samples stored for 28 days at 4 and 15 °C exhibited lower values as compared to control (day 0). The results showed greater stability of nutritional parameters at 4 °C compared to 15 °C.