The concept of sustainable development is increasingly important in the agri-food sector and global economy. International activities are undertaken to improve the efficiency of industry by reducing its negative impact on the environment. To help determine harmful human activity, the environmental footprints of products and services are calculated using the LCA (life cycle assessment) method. The purpose of this article was to explain topics of sustainable development and environmental footprints, especially the carbon footprint in the agri-food sector, based on the latest literature. The agri-food industry consumes around 30% of global energy demand. It is also a source of emissions of a significant part of greenhouse gases released into the environment. The carbon footprint of food products is determined by many factors associated with their production. Food of animal origin is more harmful and has higher carbon footprints than plant-based products. GHG emission reduction is possible due to the use of renewable energy sources and the abandonment of the use of artificial fertilizers and plant protection products.
The study investigated the effect of a combination of drying techniques: convection, microwave, and freeze-drying, on selected physical properties of the dried material (carrot) to determine which form of hybrid drying is the best alternative to traditional freeze-drying. Carrots were dried by freeze-drying, convection-drying, and microwave-drying as well as in hybrid methods: freeze-drying-convection, freeze-drying–microwave as well as convection–freeze-drying or microwave–freeze-drying. The color, porosity, shrinkage, water activity, dry matter content, and internal structure of carrots dried using various methods were examined. The dried samples obtained with the hybrid method were compared with those obtained with a single drying technique. Freeze-drying–microwave-drying (F-M) as an alternative drying method for freeze-drying allowed us to obtain dried material with a water activity similar (p < 0.05) to that of freeze-dried samples, at the same time reducing the duration of the process by 20 h. The combination of convection-drying methods with freeze-drying (K-F) and microwave-drying with freeze-drying (M-F) allowed us to obtain dried material with lower shrinkage than in the case of convection (K) or microwave (M) drying.
The study aimed to evaluate the effect of storage temperature on quality changes in freeze-dried carrot–orange–ginger (COG) snacks obtained with 2% of apple (AP) or blackcurrant (BP) pomace powder or 1.5% of pectin (LMP). The material was stored at 4, 25 and 40 °C for 1, 3, 6 and 12 months in pouches impermeable to vapour, oxygen and light. Water content and activity, texture, colour, total polyphenol content and antioxidant activity were examined to evaluate the products’ quality. During storage, water content and activity fluctuations were noted, but no critical values were exceeded. Texture properties remained stable in snacks with pomace powders compared to those with pectin, the hardness of which significantly decreased when stored at ambient and elevated temperatures. However, the product with pectin was found to change colour the least over time. The results obtained for chemical properties were not clear, but they strongly indicated the occurrence of the transformation of some chemical compounds. Overall, a lowered temperature helped to maintain the quality of the freeze-dried snacks for the longest time. The presented research contributes to the general knowledge of the behaviour of innovative products with the addition of nonconventional but sustainable compounds, revealing the potential for quality and stability improvements.
Edible hydrogel coatings or films in comparison to conventional food packaging materials are characterized as thin layers obtained from biopolymers that can be applied or enveloped onto the surface of food products. The use of lipid-containing hydrogel packaging materials, primarily as edible protective coatings for food applications, is recognized for their excellent barrier capacity against water vapor during storage. With the high brittleness of waxes and the oxidation of different fats or oils, highly stable agents are desirable. Jojoba oil obtained from the jojoba shrub is an ester of long-chain fatty acids and monovalent, long-chain alcohols, which contains natural oxidants α, β, and δ tocopherols; therefore, it is resistant to oxidation and shows high thermal stability. The production of hydrogel films and coatings involves solvent evaporation, which may occur in ambient or controlled drying conditions. The study aimed to determine the effect of drying conditions (temperature from 20 to 70 °C and relative humidity from 30 to 70%) and jojoba oil addition at the concentrations of 0, 0.5, 1.0, 1.5, and 2.0% on the selected physical properties of hydrogel edible films based on whey protein isolate. Homogenization resulted in stable, film-forming emulsions with bimodal lipid droplet distribution and a particle size close to 3 and 45 µm. When higher drying temperatures were used, the drying time was much shorter (minimum 2 h for temperature of 70 °C and relative humidity of 30%) and a more compact structure, lower water content (12.00–13.68%), and better mechanical resistance (3.48–3.93 MPa) of hydrogel whey protein films were observed. The optimal conditions for drying hydrogel whey protein films are a temperature of 50 °C and an air humidity of 30% over 3 h. Increasing the content of jojoba oil caused noticeable color changes (total color difference increased from 2.00 to 2.43 at 20 °C and from 2.58 to 3.04 at 70 °C), improved mechanical elasticity (the highest at 60 °C from 48.4 to 101.1%), and reduced water vapor permeability (the highest at 70 °C from 9.00·10−10 to 6.35·10−10 g/m·s·Pa) of the analyzed films. The observations of scanning electron micrographs showed the heterogeneity of the film surface and irregular distribution of lipid droplets in the film matrix.
The properties of fresh meat, such as high water activity, a slightly acidic reaction, and the availability of carbohydrates and proteins, make it a microbiologically unstable and easily perishable raw material. One of the oldest food preservation techniques is drying. Furthermore, non-thermal food processing techniques such as pulse electric field (PEF) treatment can be used to support the drying process and change the properties of the obtained product. Thus, this study aimed to analyze the impact of pulsed electric field treatment on the hot air-drying and freeze-drying of poultry meat as well as on the quality of the dried meat. The PEF pretreatment and drying methods significantly altered the physical characteristics of the poultry meat. The PEF treatment enhanced the efficiency of freeze-drying by electroporation, reducing drying time and shrinkage. However, in the hot air-drying, the PEF-treated samples prolonged drying, potentially due to muscle structure damage and increased shrinkage. The pretreatment techniques affected the structure of the meat and positively influenced the higher porosity and lower shrinkage. Also, drying decreased the water activity and increased the dry matter content, which ensured the safety of the final product. The freeze-dried material exhibited a higher rehydration rate, improved hygroscopic properties, and better meat color compared to the hot air-dried material. Nevertheless, the selection of the process parameters, for both the pretreatment and drying process, is crucial to ensure a high quality of the dried meat product and should be selected carefully in order to guarantee that the highest quality of the dried product is obtained.
1 December 2021 in Polish Journal of Food and Nutrition Sciences
The food industry is committed to supplying nutritious products that are attractive and convenient for consumers. Freeze-dried fruit and vegetable snacks that exemplify such products are difficult to obtain since it is necessary to use a carrier agent (usually a hydrocolloid ingredient) which...