ПРИМЕНА НА РЕВЕРЗНО-ФАЗНА ВИСОКОЕФИКАСНА ТЕЧНА ХРОМАТОГРАФИЈА ЗА ОПРЕДЕЛУВАЊЕ НА АКТИВНИТЕ КОМПОНЕНТИ ВО ПРЕПАРАТОТ INTER OF

Fast, simple, precise and accurate methods development for simultaneous determination of active ingredients phenmedipham, desmedipham and ethofumesate in a pesticide formulation Inter Of using reversed-phase (RP) high performance liquid chromatography (HPLC) and ultraviolet diode array detector (UV/DAD) is presented in this work. For realization the established purpose seven analytical columns are used: Hypersil ODS (25 cm 0.46 cm, 5 m), HS 3 3 C-18 (3.3 cm 0.46 cm, 3m), HS 3 3 C-8 (3.3 cm 0.46 cm, 3 m), LiChrospher 100 RP-18 (25 cm 0.4 cm, 5 m), Chromolith Performance RP-18e (10 cm x 0.46 cm), LiChrospher 60 RP-select B (12.5 cm x 0.4 cm, 5 m) and LiChrospher 60 RP-select B (25 cm x 0.4 cm, 5 m). RP-HPLC method is carried out on a LiChrospher 60 RP-select B (25 cm x 0.4 cm, 5 m) analytical column, with mobile phase of methanol/water (60/40, V/V), flow rate of 1 mL/min, constant column temperature at 25 oC, UV detection at 230 nm and 0.5 AUFS sensitivity level. The following parameters are determined for the developed method: retention factor, separation factor, limit of detection, limit of quantification, repeatability or intermediate precision of obtained results for retention time, peak area and peak height, the fit type between the mass of analyte and peak area or peak height, recovery of analyte and active ingredients quantity in a pesticide formulation

DETERMINATION OF SOME PESTICIDE RESIDUES IN APPLE JUICE BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

A new, simple and reliable reversed-phase high-performance liquid chromatography (RP-HPLC) method for determination of 2,4-D ((2,4-dichlorophenoxy)acetic acid), atrazine, malathion, fenitrothion and parathion residues in apple juices has been developed and validated. Successful separation and quantitative determination of analytes were performed on Purospher STAR RP-8e (30 x 4 mm, 3 μm) analytical column, with mobile phase consisted of acetonitrile/water (45/55, V/V), flow rate of 1 mL/min, constant column temperature at 25 oC and UV detection at 220 nm and 270 nm. A solid-phase extraction (SPE) was used for concentration and clean-up of analytes. Specificity, selectivity, linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ) were tested for the method validation according to European Commission guidelines for pesticide residue analytical methods, and all performance characteristics were found within acceptance criteria. Calibration curves were linear within the range less than 50 % of the maximum residue limit (MRL) values and 20 % above for all investigated pesticides (R2 > 0.95). Under the stipulated conditions, values for relative standard deviations (RSD) of retention times and peak areas were 0.12 % - 0.28 % and 0.08 % - 8.50 %, respectively. The obtained values for recoveries ranged from 93.65 % - 118.62 %, with RSD ≤ 5.64 %. This method was successfully applied for determination of investigated pesticide residues in apple juice samples, which were taken from Macedonian markets. The run time of assay obtained from this chromatography condition was about 4 min

HPLC METHOD FOR DETERMINATION OF ACTIVE INGREDIENTS IN PESTICIDE FORMULATION SWITCH 62,5 WG

Analytical quality control for pesticides achieved using appropriate methods is essential in providing their safe and adequate use in agriculture. This study presents a precise, fast, and a simple analytical method for determining active ingredients cyprodinil and fludioxonil in a fungicide formulation Switch 62,5 WG using high-performance liquid chromatography (HPLC). The development of the HPLC method was performed on a ZORBAX Eclipse Plus C18 (50 x 4.6 mm, 1.8 µm) analytical column using isocratic elution with a mobile phase consisting of acetonitrile and water in volume ratio 70:30, a flow rate of 1 mL/min, a constant column temperature at 25 ºC and UV detection at 220 and 270 nm. The run time of analysis under these chromatographic conditions was about 1.5 min. The method was validated by testing specificity, linearity, precision, recovery, LOD, LOQ, and accuracy according to the CIPAC (Collaborative International Pesticides Analytical Council) and SANCO (Directorate General Health and Consumer Protection) guidelines, and all the tested parameters were found within acceptance criteria. The values for multiple correlation coefficient (R2 ≥ 0.99), relative standard deviation (RSD < 1 %), recoveries ranged from 98.95 - 102.26 %, revealed that the developed method has a good linearity, precision and accuracy. The proposed method is suitable for routine analysis of active ingredients cyprodinil and fludioxonil in the formulation Switch 62,5 WG

MARKET RESEARCH - HOW INTERESTED ARE CONSUMERS IN MEAT PRODUCTS WITH FEWER E-NUMBERS IN THEIR DECLARATION

Abstract Market today offers a wide range of meat products. Additives are widely used in the meat industry. Their usage is aimed to make meat products safer to eat, to extend their shelf life, improve their sensory characteristics, etc. The main objective of the paper is to be done market research and how interested are consumers in meat products with fewer Е-numbers in their declaration by carrying out a survey. In order to describe the analysed sample statistical analysis is applied and the results are shown in an analytical and graphical form. According to the results obtained from this research it can be concluded that out of 210 respondents, 126 (60.00%) are informed about the meaning of the term "additive", 159 (75.71%) respondents know that the additives are labelled with E-numbers, whereas 122 (58.10%) respondents know the purposes why food additives are used in the food industry. However, competent institutions need to work on educating and informing consumers. Most respondents avoid meat products due to the presence of: flavour enhancers, emulsifiers, preservatives, food colours and stabilizers. 159 (75.71%) of the respondents believe that the market should offer meat products with a reduced presence of E-numbers in the declaration. Today, modern consumers are becoming more health conscious and they are changing their eating habits. Therefore, they are increasingly focused on natural meat products, where E-numbers are less represented in the declaration

RAPID RESOLUTION LIQUID CHROMATOGRAPHY METHOD FOR DETERMINATION OF CHLOROGENIC ACID IN ECHINACEA EXTRACTS

This study presents a development and validation of a new, fast, efficient and cost effective reversed-phase rapid resolution liquid chromatography (RP-RRLC) method for determination of chlorogenic acid in echinacea extracts. The optimum separation with symmetrical peak shape and good index purity of the analyte was achieved on a Poroshell 120 EC-18 (50 mm x 3 mm; 2.7 µm) analytical column, mobile phase consisted of acetonitrile/(water with 1 % phosphoric acid), (10/90, V/V)in isocratic elution with flow rate of 1 mL/min and UV diode-array detection (UV-DAD) at 325 nm. The developed method was validated by testing specificity, selectivity, linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). The calibration curve of chlorogenic acid followed Beer’s law within the range 28.97 ng - 362.19 ng (R2 = 0.9994). The LOD was 0.29 pg, while LOQ was 0.96pg. The intra-day precisions was evaluated for the retention time, peak area and peak height and the calculated values for relative standard deviations (RSD) were 0.21 %, 0.11 % and 0.22 %, respectively. The mean recoveries ranged from 98.75 to 104.63 % and RSD was less than 0.23 %. The developed method was successfully applied for identification and quantification of chlorogenic acid in three samples of echinacea extracts, taken from local pharmacies

SPECTROPHOTOMETRIC DETERMINATION OF TOTAL POLYPHENOLIC AND FLAVONOID CONTENT IN TOMATO

Polyphenolic compounds are a heterogeneous group of secondary plant metabolites and one of the most important classes of natural antioxidants. Polyphenols can be found in apples, onions, dark chocolate, red cabbage, tomatoes, and many other fruits and vegetables. The aim of the present investigation was the determination of total polyphenolic content (TPC) and total flavonoid content (TFC) in two tomato cultivars "Belle F1" and "Perugino F1" by UV-Vis spectroscopy. Determination of TPC was performed by Folin–Ciocâlteu assay with gallic acid as a reference standard. In order to determine TFC, quercetin was used as a reference standard. The obtained results showed that the TPC is higher in the tomato Perugino F1 (9.18 ± 0.16 mg / 100 g) compared to the hybrid "Belle F1" (6.23 ± 0.03 mg / 100 g)

ВЛИЈАНИЕ НА АМБАЛАЖНИОТ МАТЕРИЈАЛ ВРЗ КВАЛИТЕТОТ И БЕЗБЕДНОСТА НА ПРЕХРАНБЕНИТЕ ПРОИЗВОДИ

Polyethylene terephthalate (PET) is the main packaging material for many food products, particularly carbonated beverages and bottled water. The strength and permeability properties of PET are very good for packaging of beverages, its resistance to chemicals is high and it has a high degree of transparency. Acetaldehyde and formaldehyde are formed during the thermoforming of PET containers. After cooling, acetaldehyde and formaldehyde remain trapped in the walls of a PET bottle and may migrate into the water after filling and storage. Taking into consideration all this, the objective of this investigation is determination the concentration of acetaldehyde and formaldehyde in PET containers of different volumes, made by various manufacturers of bottled mineral carbonated and noncarbonated water, and exposed to different temperatures. The migration of acetaldehyde and formaldehyde from PET bottles into mineral carbonated and noncarbonated water was determined by high performance liquid chromatography. Taking into consideration that formaldehyde and acetaldehyde have no UV active or fluorescent group, the chromatography was preceded by derivatization in a closed system (due to a low boiling point of acetaldehyde and formaldehyde), which transforms carbonyl compounds into UV active compounds

THE EFFECT OF SWISS CHARD POWDER AND STARTER CULTURES ON COLOUR DEVELOPMENT IN SMOKED PORK LOIN

The aim of this research is to determine the influence of starter cultures and Swiss chard powder, as an alternative naturally occurring nitrite source, on development of superficial and cross-section colour in smoked pork loin produced in industrial conditions. It has been confirmed that smoked pork loin where nitrite and starter culture have been added (group III) has the most favorable instrumental values ​​L, a and b of the colour at surface and fresh cross-section. In group IV (Swiss chard powder and starter culture), the colour develops only on the periphery of the smoked pork loin, which is due to the low content of nitrite during all production stages. Nitrate-reducing bacteria present in starter cultures are reducing nitrates from Swiss chard powder to nitrites. Formed nitrites react rapidly with ascorbic acid and because of that do not have the ability to react with myoglobin to contribute to the development of a red colour in the middle part of the meat. The differences in the colour, observed in the instrumentally measured L, a and b-values at the surface and fresh cross-section between the groups of productions stages, are statistically significant (p < 0.05)

ВЛИЈАНИЕ НА АМБАЛАЖАТА ВРЗ РОКОТ НА ТРАЕЊЕ НА ПРЕХРАНБЕНИТЕ ПРОИЗВОДИ

The shelf life of the food was actually period in which the product is considered suitable for consumption. By understanding the factors that influenceto the shelf life of the product, it is possible manipulation of these factors in order to extend the shelf life of the product. There are several factors that affect the shelf life such as: the manufacture of the product, freezing , chemical changes, as well as, food packaging. These factors can contribute to reducing the amount of food that is thrown away because of the short shelf life. There is scientific basis for assessing the shelf life using mathematical expressions that are useful in predicting the degradation of food products during storage. It is based on the principles of chemical kinetics. Actually, the changes in the quality (Q) can be observed and measured over time. The shelf life of the food products based on changes in quality in relation to the time can follow kinetics of zero order or first order. Using these calculations the phases of reducing the quality and accuracy of the product can be predicted

TOTAL ANTHOCYANINS IN FRESH FRUIT AND COMPOTE OF "OBLACINSKA" SOUR CHERRY (PRUNUS CERASUS L.)

Anthocyanins are secondary metabolites of plants in the flavonoid family. Red and blue fruits are the main sources of anthocyanins, because cyanidin-3-glucoside is one of the most common and gives the red colour of the fruit. They are soluble in water and are 100 % absorbed by the human body. Anthocyanins are powerful antioxidants that protect our body from free radicals. They have a unique ability to resist ultraviolet light and reduce the risk of serious illness. Nutritionists recommend the use of anthocyanins in amounts of 10 to 15 mg per day. Sour cherry (Prunus cerasus L.) contains high levels of anthocyanins that have strong antioxidant and anti-inflammatory properties. In this paper, for the determination of the content of total anthocyanins, fresh fruits from the sour cherry "Oblacinska" variety and compotes of the same variety sweetened with sucrose and stevia are used. Anthocyanins are examined according to the following method: AOAC Official Method 2005.02, Total Monomeric Anthocyanin Pigment Content of Fruit Juices, Beverages, Natural Colorants, and Wines, pH Differential Method. The content of anthocyanins is in the following order: 32.00 mg cyanidin-3-glucoside equivalents / 100 g in fresh sour cherry fruits, 16.10 mg cyanidin-3-glucoside equivalents / 100 g in sour cherry compote with sucrose and 16.12 mg cyanidin-3-glucoside equivalents / 100 g in sour cherry compote with stevia