Influence of Frying Time and Addition of Rice Starch on Oil Uptake and Textural Properties of Fried Coated Chicken Meat

Rice starch in shares of 6, 8 and 10 % was used as replacement for eggs in the coating mixtures used for coating of meat before frying. After frying of meat at 170 0C for 4, 6 and 8 minutes, effects of frying time and addition of starch on oil uptake and meat texture were evaluated. Instrumental texture analysis of fried coated chicken meat was conducted, as well as Soxhlet method for determining of oil content in samples. Statistical analysis of relevant texture properties of fried meat was performed. Hardness of fried meat samples decreased with increase of the starch content in mixture. Elasticity of meat increased as a result of coatings water holding capability and consequent prevention of meat drying. Oil content in samples coated with mixtures containing rice starch decreased with increase of starch share. Optimal frying time was 6 minutes, which with 10 % of mass share of rice starch produced samples with 35.54 % less oil

Applications of Power Ultrasound for Foodstuffs Processing

U posljednje vrijeme su mnoga istraživanja usmjerena na razvoj novih, blažih tehnika obrade hrane za koje se pretpostavlja da mogu zamijeniti neke tradicionalne toplinski temeljene procese prerade u prehrambenoj industriji, radi dobivanja prehrambenih proizvoda visoke kvalitete. Sačuvani i unaprijeđeni, aroma, okus, miris, vizualni izgled, boja, teksturalna i nutritivna svojstva samo su neke značajke na taj način obrađene hrane. Tako se u prvom redu istražuje primjena visokog hidrostatskog tlaka, ultrazvuka visokog intenziteta, oscilirajućih magnetskih polja, mikrovalova te pulsirajućih električnih polja. Zajedničko je svim ovim tehnikama da se obrada materijala odvija na sobnoj temperaturi, odnosno da dolazi do neznatnog povišenja temperature kao posljedice obrade te da sam proces traje kratko i to od jedne do deset minuta. Korištenje ultrazvuka u prehrambenoj industriji i prehrambenoj tehnologiji predmet je intenzivnog istraživanja i primjene unazad nekoliko desetaka godina, kako kao metode za nerazorna ispitivanja tj. dijagnostičke metode za određivanje različitih svojstava prehrambenih sirovina i proizvoda (ultrazvuk niskog intenziteta), te kao razorne metode gdje se ultrazvuk koristi kao tehnika kojom se prehrambenoj sirovini ili materijalu mijenjaju fizikalno-kemijska svojstva (ultrazvuk visokog intenziteta). U ovom radu opisana je primjena tehnologije ultrazvuka visokog intenziteta u prehrambenoj industriji i tehnologiji.Many investigations recently deal with development of new, sophisticated and moderated techniques for food processing for which it can be assumed that might improve or even replace some traditional heat based processes within food technology and food industry to obtain high quality food products. Preserved and improved flavour, taste, odour, visual appearance, colour, textural and nutritive properties as well are some of the qualities for such treated and processed foods. Primarily applications of high hydrostatic pressure, hi-intensity ultrasound, oscilating magnetic fields, microwaves and pulsed electric fields are being investigated. In common for all mentioned technologies is that processing of foods is conducted under conditions of ambient temperature namely slightly increase of temperature occurs as a consequence of alteration of foodstuffs during which process itself last between one and ten minutes. Potential applications of ultrasound in food technology and food industry has been matter of intensive research in previous two decades and was divided in two different groups. First (low intensity ultrasound) as powerfull tool for non-destructive applications i.e. diagnostic methods for various properties determination of food raw materials and final food products, and second (hi intensity ultrasound) where ultrasound is used to change physical-chemical properties of foods. In this work applications of hi intensity ultrasound in food technology and food industry has been described

Spouted bed, theory and applications

U suvremenoj industriji se sve više koriste procesi i uređaji u kojima se koriste dvofazni sustavi. Primjena ovih sustava i uređaja daje široke mogućnosti unapređenja i primjene u praksi. U ovom radu prikazani su značajniji rezultati istraživanja vezanih za specifi čni oblik fluidiziranog sloja fontanski sloj. Na osnovu dostupnih literaturnih podataka dat je pregled osnovnih defi nicija i podataka za najčešće upotrebljavane jednadžbe za proračun maksimalne visine fontanskog sloja, minimalne i maksimalne površinske brzine fontaniranja, srednjeg promjera mlaza u fontanskom sloju, pada tlaka i optimalnog kuta otvora konusa.Modern industry more and more is useful processes and equipment in which are useful two-phase sistem. Practical this sistem and equipment contribute extended feasibility advancing and apply to practice. In this paper are shown characteristically research rezult in this connection with fluidization bed spouted bed. On based acessibility literature data gives review founded defi nition and data for most often used equations for calculated maximum spoutable bed height, minimum and maximum superfi cial velocity for spouting, spout diameter, pressure drop and optimal angle included by column base cone

Effect of selected starter cultures on production, properties and shelf life of fresh type cheese

The aim of this study was to examine the influence of different starter cultures including protective culture on the production and properties of fresh cheese. Fresh cheeses were produced from pasteurized milk by adding mesophilic starter cultures, mesophilic cultures and liquid rennet and by adding protective culture. All samples were analysed for acidity (active and titratable), microbiological quality, texture, colour and sensory properties during 21 days of cold storage. Additionally, milk fat, the total dry matter, total proteins and mineral content were determined in all cheese samples on the first day of storage. It could be observed that the used mesophilic culture in general did not affect chemical composition of cheese. As expected, during the storage period acidity in all cheeses decreased, while the number of microorganisms increased, whereby that changes were significantly slowed down in cheese produced by adding protective culture. Scores of sensory evaluation were high during the entire storage period for all cheeses, but samples containing and cheese protective cultures achieved the highest score (18.56) at the first as well as at the last day of storage (17.98). According to all analyses, it is evident that the shelf life of cheese produced by adding protective culture has been prolonged for 12 days in comparison to samples produced without protective culture, and accounted 21 days when properly cool stored. In conclusion, the addition of protective culture might be useful for extending the shelf life and maintaining sensory properties as well as colour of fresh cheese

Poroznost piletine obložene smjesom za pohanje

Effects of the addition of rice starch and dietary fibres (pectin and Fibrex) on the porosity of basic frying mixture formulations (corn flour, salt, spices) and oil uptake of coated chicken meat have been evaluated. Porosity of the fried breaded chicken meat was calculated from particle and bulk density. Pore size and particle size distribution were determined using microscopy image analysis and particle density by mercury intrusion porosimeter (MIP). Since there is a wide range of particle diameters, significant differences in pore size distribution were found. Also, pore structure appeared to be affected by oil absorption. Mercury entrapment in pores decreased significantly during 8 min of frying. The obtained results show that porosity of the samples is different for different frying mixture formulations and indicate that there is a difference in the extent of oil uptake for different formulations due to film forming capabilities of dietary fibres (pectin and Fibrex).U radu su ispitivani utjecaj dodatka rižinog škroba i prehrambenih vlakana (pektin i Fibrex) na poroznost osnovne smjese za oblaganje (kukuruzno brašno, sol, začini), te količina upijenog ulja u pohanoj piletini. Poroznost pržene piletine mjerena je kombinacijom gustoće čestica i nasipne gustoće. Veličina pora i raspodjela veličine čestica utvrđeni su živinim porozimetrom. Izmjeren je široki raspon promjera čestica, te značajne razlike u veličini pora. Struktura pora mijenjala se pod utjecajem apsorpcije ulja tijekom prženja. Količina se žive zaostale u porama značajno smanjuje tijekom 8 minuta prženja, pa dobiveni rezultati pokazuju da se poroznost uzoraka bitno razlikuje u pripremljenim recepturama. To dovodi do razlike u količini upijenog ulja koja je obrnuto proporcionalna količini rižinog škroba u smjesi. Prehrambena vlakna također pridonose smanjenju upijanja ulja

Influence of High Intensity Ultrasound Treatments on Physical Properties of Sheep Milk

In this study, research was based on influence of high intensity ultrasound on inhomogeneous sheep milk. Ultrasonic processor (maximal nominal power – 100W) with the constant frequency of 30 kHz was used for milk homogenization. Changes on temperature, pH – value, density, viscosity and absorbance (500nm) are followed by given process parameters: amplitude (A = 20, 60 and 100 %); time of treatment (t = 2, 6, 10 and 15 minutes), full cycle (c = 1), probe diameters (d = 7, 10 and 14 mm). Statistical analysis was conducted and infl uence of process parameters and temperature was expressed over p – value (p<0.05; ANOVA; ANCOVA). Applications of different probe diameter have significant influence on all observed physical properties. Longer time of treatment and amplitude showed significant infl uence on temperature, absorbance and changes on viscosity of sheep milk, while on pH – value and density has no infl uence. Analyses of covariance (ANCOVA) showed significant influence of the temperature on increasing of absorbance and viscosity, while temperature has no influence on pH – value and density of ultrasonically treated milk

Influence of High Intensity Ultrasound Treatments on Physical Properties of Sheep Milk

In this study, research was based on influence of high intensity ultrasound on inhomogeneous sheep milk. Ultrasonic processor (maximal nominal power – 100W) with the constant frequency of 30 kHz was used for milk homogenization. Changes on temperature, pH – value, density, viscosity and absorbance (500nm) are followed by given process parameters: amplitude (A = 20, 60 and 100 %); time of treatment (t = 2, 6, 10 and 15 minutes), full cycle (c = 1), probe diameters (d = 7, 10 and 14 mm). Statistical analysis was conducted and infl uence of process parameters and temperature was expressed over p – value (p<0.05; ANOVA; ANCOVA). Applications of different probe diameter have significant influence on all observed physical properties. Longer time of treatment and amplitude showed significant infl uence on temperature, absorbance and changes on viscosity of sheep milk, while on pH – value and density has no infl uence. Analyses of covariance (ANCOVA) showed significant influence of the temperature on increasing of absorbance and viscosity, while temperature has no influence on pH – value and density of ultrasonically treated milk

Ultrasonically Improved Sieving of Food Materials for Manufacturing of Direct Expanded Extrudates

Particle size distribution of raw materials plays an important role in extrusion process during direct expanded extrudates manufacturing. In most of the food industries all types of fl ours come in a production plant packed in bags with certain checkmarks that consist of average size of particles expressed in μm. That particle size range is very relative, because mostly it means that size of most frequent particles is expressed. During extrusion processing of corn fl our and whey or soy proteins blends are interject, then it is very important to know precise particle size of the interjected blends. If it does not match, raw materials should be sieved and particular fractions separated. To obtain the best fraction of corn fl our for extrusion processing (200 – 450 μm), sieving was conducted in shaker “Analysette 3” with sieving times of 5, 10 and 15 minutes. For each of these three measurements an agglomerate creation was spotted, followed by the major remain of the sample at the mesh of 450 μm. Sieving was repeated with aid of ultrasound (250 W), using power generator and by ultrasonic ring with transducer (“UIS 250 L”) mounted on the sieves. Sieving was conducted again with sieving times of 5, 10 and 15 minutes, and variable amplitude of works of 25, 50 and 75% for ultrasound. Within each of these nine measurements a partial or complete agglomerate breakdown was achieved, and an optimal fraction for extrusion processing was acquired. For the desirable particle size fraction in range of 200 – 450 μm for extrusion, under the conditions of 10 and 15 minutes of sieving time with amplitude work of 75%, the most of the sample remained within desirable range (83,79% and 83.4%)

Determination of Textural Properties of Gouda Cheese

Tekstura kao manifestacija nekih reoloških svojstava namirnice jedna je od osnovnih organoleptičkih svojstava, te ima vrlo važnu ulogu pri rukovanju, obradi i ponašanju namirnica. Potrošačima je također tekstura jedan od važnijih parametara kojim se rukovode prilikom odabira proizvoda. Na analizatoru teksture TA.HDPlus izvršena je instrumentalna analiza pet sireva Gouda različitih proizvođača koji su prisutni na hrvatskom tržištu. Od teksturalnih parametara ispitivane su tvrdoća, rad potreban za žvakanje, elastičnost i adhezivnost te njihova ovisnost o udjelu suhe tvari.Najtvrđim (11,88 N ± 1,79) su se pokazali uzorci s najvećim udjelom suhe tvari (55 %). Padom udjela suhe tvari smanjuju se vrijednosti tvrdoće, adhezivnosti i rada potrebnog za prvi zagriz. Elastičnost raste s porastom udjela vode te je najveća elastičnost bila 14,02 mm, uz 50 % udjela vode. Rad potreban za prvi zagriz linearno ovisi o sva tri teksturna parametra gdje je 138,24 mJ najveća dobivena vrijednost pri 55 % suhe tvari.Texture as a manifestation of some rheological properties of foodstuffs is one of the primary organoleptic properties. It has important role in handling, processing and behaviour of the foodstuffs. From consumer aspect, texture is also one of the more important parameters which they use for their buying decisions. Instrumental analysis on TA.HDPlus texture analyzer of five Gouda cheeses from various Croatian producers was conducted. From wide range of textural properties, hardness, work for mastication, elasticity and adhesivity were chosen for testing, as well as for comparing with dry matter content. Hardest (11,88 N ± 1,79) samples have largest share of dry matter (55 %). With decrease of dry matter content, values for hardness, adhesivity and work dropped. Elasticity rise with increase of water content, i.e. largest elasticity was 14,02 mm, with 50 % water content. Work linearly depends on all three measured textural properties. 138,24 mJ was largest measured value for sample, which contain 55 % of dry matter

Application of Low - intensity Ultrasound („pulse – echo“) for Damage Detection of Packaging Materials and Foreign Bodies in Packaged Products

Sa ciljem što preciznijeg i jasnijeg defi niranja eventualnih nedostataka ambalažnog materijala u smislu detekcije oštećenja kao i otkrivanje stranih tijela unutar upakiranog gotovog prehrambenog proizvoda danas se primjenjuju razne tehnike čija je temeljna osnova utjecaj ultrazvuk niskog intenziteta. Ultrazvuk kao mehanička vibracija sličan je čujnome zvuku. Nerazorna (dijagnostička) ispitivanja najčešće se provode u frekvencijskom području između 1MHz – 30 MHz i karakteriziraju ga niski intenziteti (<1 W/cm²). U ovom radu prikazani su utjecaji različitih tehnika primjene ultrazvuka niskog intenziteta kao što su „puls – jeka“ metoda kao najučinkovitija metoda pri detekciji stranih tijela zaostalih unutar ambalažnog materijala tijekom proizvodnog procesa, kao i mjerenje utjecaja akustičke impedancije sa ciljem dobivanja što jasnije slike analiziranih spojnih mjesta ambalažnog materijala. Prikazane su i osnovne značajke BAI (eng. Backscattering Amplitude Integral) tehnike slikanja kako bi se analizom dobivene slike identifi cirale pukotine i oštećenja spojnih mjesta ambalažnog materijala.In order to achieve precise and clear definitions of possible flaws, imperfections in packaging materials, low intensity ultrasound is the basic applied technique. The most useful applications of low intensity ultrasound are for detection of foreign bodies, damages and holes inside of the packaging materials. Ultrasound is mechanical vibration similar to audible sound. Diagnostic investigations were performed in frequency range between 1MHz – 30MHz with low intensity (<1 W/cm²). This article indicate different techniques of using low intensity ultrasound such as “pulse – echo” method like a more effective method for detection of foreign bodies inside of packaging materials during production. The main goal of measuring of acoustic impedance is acquiring distinct images of analyzed contact places of packaging materials. There are also shown the basic characteristics of BAI (Backscattering Amplitude Integral) technique of getting images and their analysis for identification of damages of connecting places of packaging materials