Mogućnost primjene bakterije Lactobacillus reuteri, izolirane iz kiselog tijesta, kao dodatka starter-kulturi, radi poboljšanja kakvoće kruha

Retardation of microbial spoilage of bread can be achieved by the use of spontaneous sourdough with an antimicrobial activity. This study was undertaken to identify lactic acid bacteria naturally occurring in spontaneous sourdough and use them for quality improvement and prolonging shelf life of rye, wheat and rye with wheat bread. Identification of isolates from spontaneous sourdough by pyrosequencing assay showed that Lactobacillus reuteri were dominant lactic acid bacteria. The isolates showed a wide range of antimicrobial activity and displayed a synergistic activity against other lactobacilli, some lactococci and foodborne yeasts. The best application of spontaneous sourdough was noticed in the rye bread with the lowest crumb fi rmness of the fi nal product, although the sensory results of wheat and rye with wheat bread did not statistically diff er from control bread. L. reuteri showed a high preserving capacity against fungi during storage. This may be due to bacteriocins and various fatty acids secreted into the growth medium that were identified by agar well diffusion assay and gas chromatography. L. reuteri showing high antimicrobial activity have the potential to be used as a starter additive that could improve safety and/or shelf life of bread.Usporavanje mikrobnog kvarenja kruha može se postići uporabom kiselog tijesta koje ima antimikrobni učinak. U ovom su radu identificirane bakterije mliječno-kiselog vrenja prirodno prisutne u kiselom tijestu, te su upotrijebljene za poboljšanje kakvoće i produljenje trajnosti raženog, bijelog i miješanog raženog kruha. Pirosekvenciranjem su identificirani izolati iz kiselog tijesta, te je utvrđeno da među mliječno-kiselim bakterijama prevladava bakterija Lactobacillus reuteri. Izolati su imali antimikrobni učinak na razne uzročnike kvarenja i sinergistički učinak na druge vrste bakterija Lactobacillus i Lactococcus, te na kvasce. Najbolji je učinak dodatka izolata iz kiselog tijesta postignut u raženom kruhu, koji je imao najmanju tvrdoću mrvica, no senzorska se svojstva bijelog i miješanog raženog kruha, u usporedbi s kontrolnim uzorkom, nisu bitno promijenila. Bakterija L. reuteri učinkovito je spriječila pojavu plijesni na kruhu tijekom skladištenja, vjerojatno zato što je u podlogu za rast lučila bakteriocine, koji su identificirani pomoću metode difuzije u jažicama agara, te razne masne kiseline, određene plinskom kromatografijom. Zaključeno je da L. reuteri ima izražen antimikrobni učinak, pa se može upotrijebiti kao dodatak starter-kulturi radi sprečavanja kvarenja i/ili produljenja trajnosti kruha

Challenges, gaps, and opportunities

UID/AGR/04129/LEAF UIDB/04647/2020 UIDP/04647/2020Urban agriculture (UA) plays a key role in the circular metabolism of cities, as it can use water resources, nutrients, and other materials recovered from streams that currently leave the city as solid waste or as wastewater to produce new food and biomass. The ecosystem services of urban green spaces and infrastructures and the productivity of specific urban agricultural technologies have been discussed in literature. However, the understanding of input and output (I/O) streams of different nature-based solutions (NBS) is not yet sufficient to identify the challenges and opportunities they offer for strengthening circularity in UA. We propose a series of agriculture NBS, which, implemented in cities, would address circularity challenges in different urban spaces. To identify the challenges, gaps, and opportunities related to the enhancement of resources management of agriculture NBS, we evaluated NBS units, interventions, and supporting units, and analyzed I/O streams as links of urban circularity. A broader understanding of the food-related urban streams is important to recover resources and adapt the distribution system accordingly. As a result, we pinpointed the gaps that hinder the development of UA as a potential opportunity within the framework of the Circular City.publishersversionpublishe

Eat or Throw Away? Factors Differentiating High Food Wasters from Low Food Wasters

More than half of food waste is generated at the household level, and therefore, it is important to tackle and attempt to solve the problem of consumer food waste. This study aimed to identify factors differentiating high food wasters from low food wasters. A large-scale survey was conducted in Lithuania. A total of 1001 respondents had participated in this survey and were selected using a multi-stage probability sample. Data were collected through face-to-face interviews using a structured questionnaire. Binary logistic regression modelling was used to analyse the effect of socio-demographics, food-related behaviours, attitudes towards food waste, and knowledge of date labelling on levels of food waste. Impulse buying, inappropriate food preparation practices, non-consumption of leftovers, lack of concern about food waste, and worry about food poisoning were related to higher food waste. On the other hand, correct planning practices and knowledge of date labelling were related to lower food waste. The findings of this study have practical implications for designing interventions aimed at reducing consumer food waste

Potential of Lactobacillus reuteri from Spontaneous Sourdough as a Starter Additive for Improving Quality Parameters of Bread

Retardation of microbial spoilage of bread can be achieved by the use of spontaneous sourdough with an antimicrobial activity. This study was undertaken to identify lactic acid bacteria naturally occurring in spontaneous sourdough and use them for quality improvement and prolonging shelf life of rye, wheat and rye with wheat bread. Identification of isolates from spontaneous sourdough by pyrosequencing assay showed that Lactobacillus reuteri were dominant lactic acid bacteria. The isolates showed a wide range of antimicrobial activity and displayed a synergistic activity against other lactobacilli, some lactococci and foodborne yeasts. The best application of spontaneous sourdough was noticed in the rye bread with the lowest crumb fi rmness of the fi nal product, although the sensory results of wheat and rye with wheat bread did not statistically diff er from control bread. L. reuteri showed a high preserving capacity against fungi during storage. This may be due to bacteriocins and various fatty acids secreted into the growth medium that were identified by agar well diffusion assay and gas chromatography. L. reuteri showing high antimicrobial activity have the potential to be used as a starter additive that could improve safety and/or shelf life of bread

Characterization of the Quality and Oxidative Stability of Hemp-Oil-Based Oleogels as an Animal Fat Substitute for Meat Patties

The effect of the incorporation of rice bran wax (5%; 7%) or candelilla wax (3%; 7%) for production of hemp-oil-based oleogels was analyzed in this study. The experiment was carried out to replace between 0 and 100% of animal fat in meat patties with oleogels. Free fatty acids (FFAs), acid value (AV), oxidative stability index (OSI), conjugated diene value, malondialdehyde value, physicochemical properties, and the sensory properties of oleogels and meat patties were studied. The results indicated that hemp oil had more polyunsaturated fatty acids and lower oxidative stability when compared to oleogels. The OSI for oil was 3.1 h, while for oleogels it was 3.4–3.6 (candelilla case) or 3.7–3.9 (rice bran). Oleogels were able to match pork fat texture properties such as spreadability and adhesiveness in meat patties. However, sensory data for cooked meat patties with animal fat fully replaced by oleogels revealed that samples with 100% pork fat had higher juiciness and taste intensity. Our results showed that a wax-based oleogel had a higher oxidative stability and nutritional profile, but further investigations to mimic pork fat properties in meat patties are necessary

Oat β-glucan in milk products: impact on human health

The aim of this study was to determine the impact of the bioactive ingredient – oat β-glucan – on the quality characteristics of the fermented milk products (kefir, yogurt and fermented milk beverages) made on buttermilk-skimmed milk mixture base and establish the influence of the consumption of one of them on the health characteristics of volunteers. The enrichment of fermented milk products with 0.6 % oat β-glucan had no impact on the fermentation time, enhanced the apparent viscosity and changed sensory properties. The experiments of medical nutrition of volunteers showed a significant decrease of total (p<0.05) and low density lipoprotein (p<0.05) cholesterol, increase in high density lipoprotein cholesterol (p<0.01) in their blood after a 21-day period of consumption of fermented product with β-glucan. According to these findings, consumption of fermented milk beverage prepared on the buttermilk-skimmed milk base and enriched with oat β-glucan had a beneficial effect on human health

Investigation of in vitro and in vivo digestibility of black soldier fly (Hermetia illucens L.) larvae protein

In this work, the in vitro and in vivo digestibility of the dried and low-fat black soldier fly (BSF, Hermetia illucens L.) larvae was carried out. The in vitro experiments demonstrated that the digestibility of the dried larvae protein was only 48%. Meanwhile, the protein digestibility of the defatted larvae biomass reached 75%. Based on these findings, the experimental feeds were composed: (a) control feed containing casein, (b) test feed containing defatted larvae biomass and (c) protein-free feed. For protein digestibility studies, experimental feeds were tested in vitro and in vivo. It was found that digestibility of larvae protein in vivo and in vitro reached 85% and 41% respectively. The DIAAS value (73%) for BSF larvae protein digestibility in vivo was determined for the first time. The obtained results suggest that larvae possess an easy digestible AA, therefore, they can be used as highly bio-available protein source for human nutrition

Effect of NSP degrading enzymes and prebiotics on quality and texture profile of laying hen’s eggs

The trial was conducted to investigate the supplementation of NSP degrading enzymes, prebiotics and its combination on the laying hens’ performance and quality of eggs. Lohman Brown laying hens aged 38 weeks were assigned to 4 dietary treatments for 8 weeks. The dietary treatments were: 1) control (C), 2) compound feed supplemented with enzymes (endo-1,4-β-xylanase 22000 VU/g, endo-1,3(4)-β-glucanase 30000 VU/g and endo-1,4 -β-glucanase (cellulase) 6400 DNS units/g of feed) (E), 3) compound feed with prebiotics (mannanoligosaccharides (MOS) 1.0 kg/t of feed) (P), 4) compound feed with NSP degrading enzymes (endo-1,4-β-xylanase 22000 VU/g, endo-1,3(4)-β-glucanase 30000 VU/g, endo-1,4 -β-glucanase (cellulase) 6400 DNS units/g of feed) and prebiotics (MOS 1.0 kg/t of feed) (EP). All laying hens were kept under the same conditions. Egg’s quality was determined using automatic egg quality analyzer and thickness of eggshell was evaluated with electronic micrometer. The texture characteristics were determined with the universal texture analyzer Instron 3343. Instrumental colour measurements of eggs were performed using a spectrophotometer Konica Minolta. Egg weight of E group was increased by 6%, but feed conversion ratio to produce 1 kg of eggs was decreased by 11%, compared to C group (P<0.05). Enzymes and MOS did not significantly effect egg quality parameters, but in E group shell weight increased by 9% (P<0.05). In addition of enzymes, the hens had produced eggs with higher albumen L* scores (P<0.05). Diet supplementation with enzymes had no significant effects on the yolk colour. In E group of laying hens, the egg mass and egg shell thickness were improved. The addition of enzymes and MOS mixture had highest positive effect on egg quality parameters, but had no statistically significant influence of egg’s texture and colour. Introduction Egg shell quality and egg internal quality are of major importance t