Abstract. 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 0.081The 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.

The transport of temperature sensitive products takes place under special conditions defined by specific agreements and international standards. The only exception to this rule is consumer transport. This transport is carried out by the consumer and takes place on the way home from the shop. The study examined consumers' awareness of the consumer transport of frozen food and analysed this type of transport in terms of the continuity of the cold chain. Such situation affects the deterioration of frozen food quality especially in case of its later storage in the home freezer. It was found that the average distance that customers cover from shop to home was 4.98 km. They usually used a car and covered this distance in an average of 12.85 minutes. During the summer months, this time is sufficient to partially thaw a package of frozen vegetables. Only 33% of the respondents used insulated bags to protect frozen food on the way home. When analysing the transport of frozen raw material carried out by consumers in real conditions, the use of insulated bags was found to be justified. These bags are able to keep the temperature of the packed raw material below −5°C. It was found that the legal imposition of the necessity to use such bags or the introduction by the manufacturer of frozen food of appropriate packaging protecting the food against transport at inappropriate temperatures in the summer months is necessary.

Stosowanie tradycyjnych metod oczyszczania i zatężania ścieków przemysłowych nie zawsze jest skuteczne. Użycie w tym celu metod parowania i odwróconej osmozy może generować wysokie koszty. Alternatywą może być zastosowanie kriokoncentracji. W pracy przedstawiono podstawy fizyczne procesu oraz możliwość praktycznego zastosowania kriokoncentracji do przemysłowego oczyszczania i zatężania ścieków. Szczegółowo zaprezentowano metody Niro GEA oraz metody bezpośredniej krystalizacji wody w rurowym i bębnowym wymienniku ciepła. Stwierdzono, że technologię oczyszczania ścieków przy wykorzystaniu zamrażania cechuje wiele zalet zarówno ekonomicznych, jak i praktycznych oraz wskazano na fakt, że wykorzystanie naturalnych warunków zimą może być przełomem w szerszym zastosowaniu kriokoncentracji do oczyszczania ścieków w Polsce.