23 research outputs found
Spouted Bed and Jet Impingement Fluidization in Food Industry
Spouted bed and jet impingement fluidization are the cases of classic fluidization modification obtained by proper distribution of the fluid and the construction of device. The condition for the realization of both fluidization types is strict determination of the apparatus dimensions and process parameters. The chapter presents the issues concerning the choice of optimal operating conditions and dimensions of working elements of devices for both spouted bed and jet impingement fluidization, as well as possibilities for analysis of heat transfer in the process. Furthermore, the examples of industrial application of spouted bed fluidization and jet impingement fluidization in food technology are presented
Modeli određivanja vremena potrebnog za odmrzavanje hrane ovisno o uvjetima prerade i karakteristikama gotovog proizvoda
Determining thawing times of frozen foods is a challenging problem as the thermophysical properties of the product change during thawing. A number of calculation models and solutions have been developed. The proposed solutions range from relatively simple analytical equations based on a number of assumptions to a group of empirical approaches that sometimes require complex calculations. In this paper analytical, empirical and graphical models are presented and critically reviewed. The conditions of solution, limitations and possible applications of the models are discussed. The graphical and semi-graphical models are derived from numerical methods. Using the numerical methods is not always possible as running calculations takes time, whereas the specialized software and equipment are not always cheap. For these reasons, the application of analytical-empirical models is more useful for engineering. It is demonstrated that there is no simple, accurate and feasible analytical method for thawing time prediction. Consequently, simplified methods are needed for thawing time estimation of agricultural and food products. The review reveals the need for further improvement of the existing solutions or development of new ones that will enable accurate determination of thawing time within a wide range of practical conditions of heat transfer during processing.Toplinska i fizikalna svojstva proizvoda mijenjaju se tijekom odmrzavanja, pa je određivanje vremena odmrzavanja oduvijek predstavljalo problem. Razvijeni su različiti matematički modeli za rješavanje tog problema, počevši od relativno jednostavnih analitičkih funkcija koje polaze od niza pretpostavki, pa sve do raznih empirijskih modela što uključuju složene izračune. U ovom su radu kritički prikazani analitički, empirijski i grafički modeli. Osim toga, raspravlja se o uvjetima potrebnim za rješavanje problema, ograničenju i mogućoj primjeni modela. Grafički i polugrafički modeli izvedeni su iz numeričkih metoda. Numeričke metode nisu uvijek primjenjive jer izračuni oduzimaju puno vremena, a specijalizirani su programi i oprema uglavnom skupi. Zbog toga su za primjenu u inženjerstvu prikladniji analitičko-empirijski modeli. Ovaj revijalni prikaz potvrđuje da ne postoji jednostavna, točna i u praksi lako izvediva analitička metoda određivanja vremena odmrzavanja prehrambenih proizvoda, te da treba razviti jednostavnije metode. Zaključeno je da postojeća rješenja treba poboljšati ili treba razviti nove modele koji će omogućiti precizno određivanje vremena odmrzavanja u različitim uvjetima prijenosa topline prilikom obrade hrane
Review of thawing time prediction models depending on process conditions and product characteristics
Determining thawing times of frozen foods is a challenging problem as the thermophysical properties of the product change during thawing. A number of calculation models and solutions have been developed. The proposed solutions range from relatively simple analytical equations based on a number of assumptions to a group of empirical approaches that sometimes require complex calculations. In this paper analytical, empirical and graphical models are presented and critically reviewed. The conditions of solution, limitations and possible applications of the models are discussed. The graphical and semi-graphical models are derived from numerical methods. Using the numerical methods is not always possible as running calculations takes time, whereas the specialized soft ware and equipment are not always cheap. For these reasons, the application of analytical-empirical models is more useful for engineering. It is demonstrated that there is no simple,
accurate and feasible analytical method for thawing time prediction. Consequently, simplified methods are needed for thawing time estimation of agricultural and food products. The review reveals the need for further improvement of the existing solutions or development of new ones that will enable accurate determination of thawing time within a wide range of practical conditions of heat transfer during processing
Diagnosis and treatment of thyroid cancer in children in the multicenter analysis in Poland for PPGGL
Wstęp: Zróżnicowane raki tarczycy (DTC, differentiated thyroid carcinoma) występują u dzieci rzadko. Większość przypadków wykrywanych jest w wieku 11–17 lat. W odróżnieniu od dorosłych DTC u dzieci prezentują odmienne zachowanie biologiczne. Mała liczba przypadków DTC w poszczególnych ośrodkach oraz względnie łagodny ich przebieg utrudniają ocenę występowania i leczenia DTC u dzieci w Polsce, uzależniając ją od wysiłków włożonych w uzyskanie rzetelnych danych. Autorzy przedstawiają wstępne wyniki analizy wieloośrodkowej dotyczące występowania, diagnostyki i leczenia DTC u dzieci. Materiał i metody: Podjęte badania są retrospektywną analizą obejmującą lata 2000–2005, opartą na danych z historii chorób uzyskanych z ankiet rozesłanych do ośrodków dla dzieci i dorosłych podejmujących leczenie DTC. Do analizy zgłoszono 107 pacjentów z 14 ośrodków akademickich w Polsce. Analizie poddano wiek i płeć dzieci z DTC, wielkość i lokalizację zmian w tarczycy, sposoby rozpoznawania DTC, rodzaje i zakres wykonywanych zabiegów operacyjnych oraz leczenie uzupełniające izotopem J131. Wyniki: Raka brodawkowatego stwierdzono u 83 dzieci, pęcherzykowego u 10 dzieci, a rdzeniastego u 14 dzieci. Częstość występowania DTC u dzieci w Polsce wahała się między 18 a 23 przypadkami rocznie. W województwach: mazowieckim i połączonych wielkopolskim i lubuskim wykazano w okresie 2000–2005 wyższą (24 i 25) częstość występowania DTC, w pozostałych województwach wykazywano od 2 do 10 przypadków DTC. Największą grupę pacjentów stanowiły dzieci w wieku 11–15 lat, a stosunek dziewcząt do chłopców wynosił 3,3 : 1. Klinicznie DTC prezentowały się najczęściej jako pojedyncze guzki tarczycy. Limfadenopatię szyjną w badaniu klinicznym stwierdzono u 42% pacjentów, a śródoperacyjnie u 50% dzieci. U większości pacjentów dominowały niższe stopnie zaawansowania DTC (T1 u 36% i T2 u 26% dzieci). Operacje jednoetapowe wykonano u 65% dzieci, operacje dwuetapowe u 25% dzieci, a profilaktyczne tyreoidektomie u 79% dzieci z grupy pacjentów z rakiem rdzeniastym tarczycy (MTC, medullary thyroid cancinoma) i mutacją genu Ret. Leczenie izotopowe J131 podjęto u 80% dzieci. Przerzuty do płuc w scyntygrafii poterapeutycznej wykazano u 14% dzieci z DTC. Wnioski: We wnioskach podkreśla się konieczność wdrożenia na terenie całego kraju ujednoliconego i ocenianego na podstawie obiektywnych przesłanek sposobu postępowania z dziećmi z DTC.Introduction: Differentiated thyroid carcinoma (DTC) in children presents different biological behavior in comparison to adults. Authors presents preliminary results of multicenter analysis concerning incidence, diagnostics and treatment of DTC in children. Material and methods: The study is a retrospective analysis of 107 pediatric patients from 14 academic centers based on the data from 2000 to 2005 obtained by questionnaire in hospitals involved in the treatment of DTC in children. Results: Papillary thyroid cancer was diagnosed in 83 children, follicular thyroid cancer in 10 children and medullary thyroid cancer in 14 children. Incidence of DTC in children was estimated between 18 and 23 cases per year. The biggest group of patients consisted of children between 11 and 15 years of age, with girls to boys ratio 3.3 : 1. Clinically DTC in children presented most often as solitary thyroid nodule. Cervical lymphadenopathy was observed in 42% of patients. Intraoperative verification indicated metastatic nodes in 50% of children. Low stage DTC predominated (T1 in 36% and T2 in 26% of children). One step surgery was performed in 65% of children with DTC, two step surgery in 25% of patients. I131 therapy was undertaken in 80% of children. Lung metastases were indicated in post therapeutic studies in 14% of children with DTC. Prophylactic thyroidectomies were performed in 79% of children in the group of patients with MTC and RET gene mutations. Conclusions: The necessity of introduction of unified therapeutic standard in children with DTC in Poland is underlined
Brašno - Kruh '15
Proceedings contains 28 original research articles presented at 8th International Congress Flour – Bread ’15 and 10th Croatian Congress of Cereal Technologists Brašno – Kruh ’1
Zastosowanie strukturyzowanych olejów roślinnych w wybranych produktach spożywczych
The joint statutory recommendations developed by the UN Food and Agriculture Organization (FAO) and the World Health Organization (WHO), the greater consumer awareness, and environmental considerations confirm the need to reduce the consumption of saturated fatty acids in the human diet. This has contributed to the development of innovative methods for replacement of saturated fats in food products. Oleogels obtained with various methods are such an alternative. Therefore, the study was focused on the analysis of the current applications of oleogels in selected food products and elucidation of the mechanisms of oleogel formation. As indicated by many researchers, oleogels (structured oils) can replace trans and saturated fats in food products and can be used in the production of spreads as well as bakery, confectionery, and dairy products. However, there are still many challenges and technological problems preventing commercial application of oleogels in the industry. It is also important to develop oleogels with higher physical and antioxidant stability, which will be used in a wide range of food products manufactured in varying production conditions and give the final products the desired sensory properties. Nevertheless, given its nutritional and environmental values, oleogelation has great potential for future industrial use.Wspólne zalecenia ustawowe opracowane przez Organizację Narodów Zjednoczonych do spraw Wyżywienia i Rolnictwa (FAO) i Światową Organizację Zdrowia (WHO), większa świadomość konsumenta, względy środowiskowe potwierdzają konieczność ograniczenia spożycia nasyconych kwasów tłuszczowych w diecie człowieka. Doprowadziło to do opracowania innowacyjnych metod zastępowania nasyconych tłuszczów w produktach spożywczych. Taką alternatywą są oleożele otrzymywane różnymi metodami. Stąd w pracy dokonano analizy aktualnych zastosowań oleożeli na wybranych produktach spożywczych wraz z mechanizmami ich powstawania. Na podstawie dokonanej analizy badań prowadzonych przez wielu autorów, oleożele (oleje strukturyzowane) mogą zastąpić tłuszcze trans i nasycone w produktach spożywczych i mieć zastosowanie w rozwoju takich jak produkty do smarowania, pieczywo, słodycze czy nabiał. Jednak nadal istnieje wiele wyzwań oraz problemów technologicznych, które uniemożliwiają komercyjne zastosowanie opracowanych oleożeli w przemyśle. Ważne jest także opracowanie oleożeli o wyższej stabilności fizycznej i antyoksydacyjnej, które mogą być stosowane w szerokim zakresie żywności w różnych warunkach produkcyjnych i nadać produktom końcowym pożądane właściwości sensoryczne. Oleożelifikacja daje jednak duży potencjał do zastosowania przemysłowego w przyszłości ze względu na wartości żywieniowe i środowiskowe
CHARACTERISTICS OF INTERACTIONS BETWEEN SOME TEXTURE PROPERTIES AND COMPOSITION OF CARRAGEENAN GELS AS A RESULT OF ITS DEFINED DIVERSIFIED FREEZING AND THAWING TREATMENT
Model samples of carrageenan gels based on water, milk and juice were air-blast frozen and frozen by immersion in glycol and in liquid nitrogen. The gel freezing rate was determined on the basis of the kinetics of freezing. Carrageenan gel samples were characterized by evaluation of its thawing drip loss and hardness determined with compression and penetration tests. Freezing in liquid nitrogen ensured the highest freezing rates. Thawing drip loss of gels significantly depended on the carrageenan content, pH of the solution, freezing method and freezing rate. The resulting relationships are linear functions with high determination coefficients. The results of compression and penetration tests prove the significant effect of the carrageenan content and pH on gel hardness. The higher carrageenan content in a sample, the higher compression force and penetration of the gel. Gel freezing resulted in lower hardness. Freezing conditions had a significant effect on the properties tested. The correlation between compression forces and penetration depending on the carrageenan content and the freezing method was described using regression equations with high determination coefficients. Gels based on milk and juice with 2.2% carrageenan content are recommended for immersion freezing at rates above 5.0 cm·h-1
The Use of Moldavian Dragonhead Bagasse in Shaping the Thermophysical and Physicochemical Properties of Ice Cream
The aim of the study was to analyze the influence of bagasse from Moldavian dragonhead (D. moldavica L.) seeds as a source of valuable nutrients on the physicochemical properties of rice milk ice cream. The basic composition of the ice cream was modified with a varied proportion of Moldavian dragonhead bagasse (MDB) (1.0%, 1.5%, 2.0%, 2.5%, and 3.0%). The analysis of fatty acids showed a high proportion of linolenic acid (n-3) in the tested ice cream, especially with 3.0% share of bagasse. The addition of MDB increased dry matter, fat, and protein contents in the ice cream. The increasing share of this additive affected the physical properties of ice cream, increasing hardness, adhesiveness and viscosity, and reducing their melting rate. The study showed a negligible effect of the increasing share of MDB on the thermophysical properties of ice cream. Due to the high nutritional value of the bagasse (with the appropriate refinement of the recipe), it is possible to obtain rice milk ice cream with potential health-promoting properties
Polysaccharides as Edible Films and Coatings: Characteristics and Influence on Fruit and Vegetable Quality—A Review
There has been a significant increase in the development of edible films and coatings in recent times, and this is expected to have a significant impact on the quality of fruit and vegetables in the coming years. Consumers expect fresh fruit and vegetables free from pesticide residues, with high quality, nutritional value and an extended shelf life. The application of coatings and edible films to fruits and vegetables represents an environmentally friendly approach to an innovative solution to this problem. Coatings and edible films can act as ecological and biodegradable packaging. The coating strategy involves a combination of natural biopolymers and appropriate preservation methods. The article presents the applicability, trends and perspectives of polysaccharide coatings and edible films and their impact on the quality of fruit and vegetables, providing an understanding of their main functions and benefits. Numerous studies show that natural polysaccharides are well suited for use as packaging material for fresh fruit and vegetables and can often be an important alternative to synthetic compounds. Natural polymer materials are a good barrier to oxygen and carbon dioxide; however, they are characterised by excessive solubility in the water environment, water vapour permeability and low extensibility. The properties of edible coatings can be modified by the addition of plasticisers, surfactants, cross-linkers, antimicrobial agents, functional additives, nanosilver particles or fruit and vegetable residues. The use of an electric field is also a promising technology here. The use of polysaccharides for the preparation of edible films and coatings is justified not only by the possibility of reducing the consumption of packaging made of synthetic polymer materials but also by the fact that the production of some natural polymers can be made using waste products generated during the processing of food raw materials
Modified gelatine structures as packaging material for frozen agricultural products
Gelatine gels modified by hydrated paper pulp (PP), ground extruded starch (ES) and hydrogel balls (HGB) were formed so that after the crosslinking process, the plates of suitable thickness could be obtained. Then the material was freeze-dried and the obtained porous gelatine structures as well as styrofoam (XPS) as the reference material were tested for thermal conductivity and bending. The temperature fields were examined during the thawing process of products placed inside the test packagings with modified gelatine structures and polystyrene as well as temperature field profile on outer surface of these packs. The studied materials resemble styrofoam in terms of thermal insulation and exhibited medium thermal conductivity ranging between 0.047 and 0.081 [W·(mK)-1]. The bending strength of the materials under investigation proved higher than that of styrofoam and this fact supports their applicability as an alternative for frozen agricultural products packages