SUBSTANTIATION OF THE METHOD OF MEAT SAMPLE PREPARATION FOR INSTRUMENTAL DETERMINATION OF CONSISTENCY

In recent years, there has been a transformation in the choice and lifestyle of Russian citizens. An increasing part of the population makes a more reasonable choice, taking into account all aspects, including the most important for meat products — these are organoleptic characteristics, in particular the consistency of the product. Consumers prefer products with the delicate, soft texture, expect good «biteness» and «cheweness». Therefore, preference is given to tender, juicy meat with a low content of connective tissue. The most commonly used method for testing meat consistency in laboratories around the world is a method that uses strength testing machines with a Warner-Bratzler blade (WB blade). In this work, the Shimadzu AGS-1kN universal testing machine (Japan) was chosen for research. Samples obtained from l. dorsi of pork and beef were selected as meat raw materials. To determine the optimal and reproducible method of sample preparation, some of them were subjected to heat treatment before analysis. In the study of samples without heat treatment, deviations from the average were more than 11%. After meat was cooked, a decrease in the relative standard deviation of the maximum shear stress from the average was achieved: from 11% in raw meat to 5% in a pork sample and 5.3% in a beef sample. The heat treatment of pre-cut samples led to a change in their geometric shape, which created additional difficulties for obtaining correct results, and also negatively affected the increase in the relative deviation to 15.5% for beef.In recent years, there has been a transformation in the choice and lifestyle of Russian citizens. An increasing part of the population makes a more reasonable choice, taking into account all aspects, including the most important for meat products — these are organoleptic characteristics, in particular the consistency of the product. Consumers prefer products with the delicate, soft texture, expect good «biteness» and «cheweness». Therefore, preference is given to tender, juicy meat with a low content of connective tissue. The most commonly used method for testing meat consistency in laboratories around the world is a method that uses strength testing machines with a Warner-Bratzler blade (WB blade). In this work, the Shimadzu AGS-1kN universal testing machine (Japan) was chosen for research. Samples obtained from l. dorsi of pork and beef were selected as meat raw materials. To determine the optimal and reproducible method of sample preparation, some of them were subjected to heat treatment before analysis. In the study of samples without heat treatment, deviations from the average were more than 11%. After meat was cooked, a decrease in the relative standard deviation of the maximum shear stress from the average was achieved: from 11% in raw meat to 5% in a pork sample and 5.3% in a beef sample. The heat treatment of pre-cut samples led to a change in their geometric shape, which created additional difficulties for obtaining correct results, and also negatively affected the increase in the relative deviation to 15.5% for beef

Comparative antioxidant effect of ascorbic acid and rosemary extract

The aim of the work was to study an effect of ascorbic acid and the extract of rosemary on fat oxidation, color characteristics, pH and moisture binding capacity of minced pork during cold storage. The antioxidants were introduced into minced pork in an amount of 0.05%. After addition of the antioxidant, minced meat was packed in the modified atmosphere with the high oxygen content and stored at a temperature of 4 ± 2 ºС for 15 days. The indicators of the hydrolytic (acid value) and oxidative (peroxide value and thiobarbituric acid value) spoilage, color characteristics, pH and moisture binding capacity (MBC) were determined during the whole storage period (0, 5, 8, 12, 15 days). An increase in the acid value was recorded in all minced meat samples during storage without a significant difference between the control and experimental samples. Addition of the antioxidants led to a decrease in the peroxide value after 12 days of minced meat storage. Malonaldehyde began to accumulate in the control and the sample with ascorbic acid on the 8th day of storage and in the sample with the rosemary extract on the 12th day. The results obtained point to inhibition of fat oxidation in the minced meat samples with the antioxidants. Addition of the antioxidants facilitated an increase in redness compared to the control. Contrary to the rosemary extract, addition of ascorbic acid led to a decrease in pH and MBC of minced meat. Therefore, the use of the rosemary extract exerted more effective action of minced pork stability during storage compared to the same dose of ascorbic acid

ИЗУЧЕНИЕ ВЛИЯНИЯ СОЛЕЙ НАТРИЯ, КАЛИЯ И КАЛЬЦИЯ НА СТАБИЛЬНОСТЬ БЕЛКОВ МЕТОДОМ ДИФФЕРЕНЦИАЛЬНОЙ СКАНИРУЮЩЕЙ КАЛОРИМЕТРИИ

Abstract Study of protein stability depending on the various technological factors allows to directionally adjust the physicochemical properties of raw meat and the quality of finished meat products. The paper investigates the possibility of using the DSC to study the influence of monovalent and divalent salts on protein thermal stability. In order to determine the effect of sodium chloride and its substitutes, potassium and calcium salts, on the thermal stability of proteins, the studies were carried out with grinded pork longissimus muscle samples salted with sodium chloride at level of 2.0% and with salt compositions containing reduced by 50% level of sodium chloride (a mixture of sodium and potassium chlorides; a mixture of sodium, potassium, and calcium chlorides) using the differential scanning calorimeter DSC Q 2000 in the temperature range of 5 °C to 100 °C and the temperature change rate of 1 K/min. It was found that the addition of potassium chloride instead of 50% of sodium chloride had no significant effect on actin and myosin resistance to thermal denaturation. Meat salting using the mixture of sodium, potassium, and calcium chlorides resulted in decrease of myofibrillar proteins stability indicating the destabilizing effect of calcium on actin and myosin. A negative correlation between the magnitude of the ionic strength and the temperature of myosin and actin denaturation has been found. The correlation coefficients were minus 0.99 and minus 0.95 for myosin and actin respectively. Reduction of denaturation temperature for myofibrillar proteins in the presence of calcium chloride opens perspectives to study the possibility of heat treatment at lower temperatures for meat products with reduced sodium content.Аннотация Изучение стабильности белков в зависимости от различных технологических факторов позволяет направленно корректировать физико-химические свойства мяса и качество готовой продукции. В статье представлены возможности использования ДСК для изучения влияния моно- и дивалентных солей на стабильность белков к термической обработке. С целью установления влияния хлорида натрия и его заменителей – солей калия и кальция на термостабильность белков были проведены исследования измельченных образцов длиннейшей мышцы свинины, посоленных поваренной солью в количестве 2,0% и композициями солей с пониженным на 50% содержанием хлорида натрия – смесь хлоридов натрия и калия; смесь хлоридом натрия, калия и кальция на дифференциальном сканирующем калориметре DSC Q 2000, с пределами изменения температур от 5 °C до 100 °C и скоростью изменения температуры - 1К/мин. Установлено, что внесение хлорида калия взамен 50% поваренной соли не оказывало существенного влияния на стабильность актина и миозина к тепловой денатурации. Посол мяса композицией со смесью хлоридов натрия, калия и кальция приводил к снижению устойчивости миофибриллярных белков, что свидетельствовало о дестабилизирующем эффекте кальция на актин и миозин. Выявлена отрицательная корреляционная зависимость между величиной ионной силы и температурой денатурации миозина и актина. Коэффициенты корреляции составили для миозина - минус 0,99, для актина - минус 0,95. Снижение температуры денатурации миофибриллярных белков в присутствии хлорида кальция открывает перспективы для проведения исследований, направленных на обоснование возможности проведения тепловой обработки мясной продукции с пониженным содержанием натрия при более низких температурах

АЛЬТЕРНАТИВНЫЕ МЕТОДЫ ТЕХНОЛОГИЧЕСКОЙ ОБРАБОТКИ ДЛЯ СНИЖЕНИЯ СОДЕРЖАНИЯ СОЛИ В МЯСНЫХ ПРОДУКТАХ

The world trends in table salt reduction in meat products contemplate the use of different methods for preservation of taste and consistency in finished products as well as shelf life prolongation. There are several approaches to a sodium chloride reduction in meat products. The paper presents a review of the foreign studies that give evidence of the possibility to maintain quality of traditional meat products produced with the reduced salt content. The studies in the field of salty taste perception established that a decrease in a salt crystal size to 20 µm enabled reducing an amount of added table salt due to an increase in the salty taste intensity in food products. Investigation of the compatibility of different taste directions is also interesting as one of the approaches to a sodium chloride reduction in food products. The use of water-in-oil-in-water (w/o/w) double emulsions allows controlling a release of encapsulated ingredients (salt), which enables enhancement of salty taste. The other alternative method of technological processing of meat raw material for reducing salt in meat products is the use of high pressure processing. This method has several advantages and allows not only an increase in the salty taste intensity, but also formation of a stable emulsion, an increase in water binding capacity of minced meat and extension of shelf-life.Мировые тенденции снижения поваренной соли в  мясной продукции предполагают использование различных способов сохранения вкуса и  консистенции готовой продукции, а  также пролонгирование сроков годности. Существует несколько подходов к  снижению хлорида натрия в  мясной продукции. В статье представлен обзор зарубежных работ, свидетельствующих о  возможности сохранения качества традиционных мясных продуктов с  пониженным содержанием соли. Исследования в  области восприятия соленого вкуса позволили установить, что уменьшения размера кристаллов соли до 20 мкм позволяет сократить количество вносимой поваренной соли за счет увеличения интенсивности соленого вкуса пищевых продуктов. В качестве еще одного подхода к снижению хлорида натрия в пищевых продуктах интерес представляет изучение совместимости различных направлений вкуса. Использование двухфазной эмульсии вода-в масле-в воде позволяет контролировать высвобождение инкапсулированных ингредиентов (соли), что позволяет усилить соленый вкус. Еще одним альтернативным способом технологической обработки мясного сырья для сокращения уровня поваренной соли в мясной продукции является применение высокого давления. Данный метод обладает целым рядом преимуществ, и позволяет не только увеличить интенсивность соленого вкуса, но и обеспечивает формирование стабильной эмульсии, повышает влагосвязывающую способность фарша и увеличивает сроки годности готового продукта.

РИСКИ И БЕЗОПАСНОСТЬ ИСПОЛЬЗОВАНИЯ НАНОТЕХНОЛОГИЙ ПИЩЕВЫХ ПРОДУКТОВ: ОБЗОР

The problem of healthy and quality nutrition has a global character. The modern development of technologies including nanotechnologies allowed obtaining materials with unique properties, which began to be actively used in food industry and agriculturebut, at the same time, require thorough investigation of their properties and effects on the human body and environment. The paper demonstrates the main directions of the nanotechnology use in the agricultural production and food industry, examines the safetyproblems and risks occurred when using nanotechnologies in food industry with account for insufficient research on the influence of food nanotechnologies on human health and environmental ecology, and presents the normative and methodical base of the RussianFederation for assurance of safe consumption of food products produced from nanomaterials.Проблема здорового и качественного питания имеет общемировой характер. Современное развитие технологий, в том числе нанотехнологий, позволило получить материалы, обладающие уникальными свойствами, которые начинают активно использоваться в пищевой промышленности и сельском хозяйстве, но и требуют тщательного изучения их свойств и воздействия, оказываемого на организм челове-ка и окружающую среду. В статье показаны основные направления применения нанотехнолологий в сельскохозяйственном производстве и пищевой промышленности, рассматриваются проблемы безопасности и риски, возникающие при использовании нанотехнологий в пищевой промышленности, учитывая, что влияние пищевых нанотехнологий на здоровье человека и экологию окружающей среды все еще мало изучено, а также представлена нормативно-методическая база Российской Федерации для обеспечения безопасного потребления продуктов питания, произведенных из наноматериалов

SUBSTANTIATION OF THE METHOD OF MEAT SAMPLE PREPARATION FOR INSTRUMENTAL DETERMINATION OF CONSISTENCY

In recent years, there has been a transformation in the choice and lifestyle of Russian citizens. An increasing part of the population makes a more reasonable choice, taking into account all aspects, including the most important for meat products — these are organoleptic characteristics, in particular the consistency of the product. Consumers prefer products with the delicate, soft texture, expect good «biteness» and «cheweness». Therefore, preference is given to tender, juicy meat with a low content of connective tissue. The most commonly used method for testing meat consistency in laboratories around the world is a method that uses strength testing machines with a Warner-Bratzler blade (WB blade). In this work, the Shimadzu AGS-1kN universal testing machine (Japan) was chosen for research. Samples obtained from l. dorsi of pork and beef were selected as meat raw materials. To determine the optimal and reproducible method of sample preparation, some of them were subjected to heat treatment before analysis. In the study of samples without heat treatment, deviations from the average were more than 11%. After meat was cooked, a decrease in the relative standard deviation of the maximum shear stress from the average was achieved: from 11% in raw meat to 5% in a pork sample and 5.3% in a beef sample. The heat treatment of pre-cut samples led to a change in their geometric shape, which created additional difficulties for obtaining correct results, and also negatively affected the increase in the relative deviation to 15.5% for beef