Volume 58, Issue No. 4

getpdf NLM PubMed Logo https://doi.org/10.17113/ftb.58.04.20.6892  

Sourdough Fermentation of Carob Flour and Its Application to Wheat Bread

Dubravka Novotni1orcid tiny, Nika Mutak1orcid tiny, Ljiljana Nanjara2orcid tiny, Saša Drakula1orcid tiny, Nikolina Čukelj Mustač1*orcid tiny, Bojana Voučko1orcid tiny
and Duška Ćurić1orcid tiny

1University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia

2University of Applied Sciences ‘Marko Marulić’, Petra Krešimira IV 30, Knin, Croatia

Article history:

Received: 10 July 2020

Accepted: 23 December 2020

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Key words:

antioxidant activity, carob sourdough, dietary fibre, partially baked frozen bread, total phenolics

Summary:

Research background. Carob is widely cultivated Mediterranean plant, but its flour is scarcely used in bread-making. Previous studies investigated the quality of wheat bread with added carob flour showing discrepant results. This study aimed to investigate the fermentation performance, antioxidant activity, rheological behaviour, and baking application of carob sourdough. 

Experimental approach. Carob sourdough was fermented with Lactobacillus brevis or Lactobacillus fermentum combined with Saccharomyces cerevisiae for 24 h at 30 °C. At the end of sourdough fermentation number of viable lactic acid bacteria and yeast cells, titratable acidity, pH value, antioxidant activity, phenolics and sugar content of sourdough were determined. Carob flour (12 % of flour mass) or sourdough equivalent (22.5 % of dough mass) was applied in making composite partially baked frozen bread. Dough rheology was monitored using a farinograph. Rebaked bread samples were evaluated for nutritive value, physical properties, and sensory attributes using a hedonic test.

Results and conclusions. By the end of fermentation, carob sourdough reached pH 4.2-4.5 and total acidity 9.9-12.3 mL of 0.1 M NaOH, sugar content was reduced for 8 g/100 g d.m, while total phenolics and antioxidant activity were increased up to 21 %, depending on the starter culture. Addition of carob flour or sourdough to wheat dough resulted in higher consistency, longer development time, and lower quality number. Regardless, bread with carob flour had significantly improved specific volume of bread. Compared with common wheat bread, carob breads had increased dietary fibre content (46 %), total phenolics (140-200 %) and antioxidant activity (240-300 %), higher shape, reduced crumbliness, unchanged firmness, and darker crumb colour. Consumers’ preference and overall acceptability scores of carob sour breads were comparable to those of wheat bread, falling into the category of 'liking very much'.

Novelty and scientific contribution. To our knowledge, this is the first study that proved the feasibility of carob sourdough fermentation using mixed starter cultures, where L. brevis associated with S. cerevisiae was better adapted to the substrate than L. fermentum. The carob sourdough could be used as a natural ingredient for improvement of nutritive value and reduction of crumbliness of partially baked frozen bread.

*Corresponding author: +38514605167
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getpdf NLM PubMed Logo https://doi.org/10.17113/ftb.58.04.20.6424  

Influence of Diclofenac on Activated Sludge Bacterial Communities in Fed-Batch Reactors

Barbara Kraigher*orcid tiny and Ines Mandic-Mulecorcid tiny

University of Ljubljana, Biotechnical Faculty, Department of Food Science and Technology, Chair of Microbiology, Večna pot 111,

1000 Ljubljana, Slovenia

 

Article history:

Received: 24 June 2019

Accepted: 24 November 2020

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Key words:

activated sludge, pharmaceuticals, diclofenac, bacterial community T-RFLP, Pseudomonas

Summary:

Research background. The occurrence and environmental toxicity of pharmaceuticals have recently attracted increasing attention. Diclofenac is a highly consumed non-steroidal anti-inflammatory drug, which is often detected in wastewaters, but investigations of its influence on bacteria are scarce. 

Experimental approach. We investigated the influence of this pharmaceutical on bacterial community in activated sludge exposed to increasing concentrations of diclofenac in fed-batch reactors over 41 days. Nitrification activity of the activated sludge was measured and changes in bacterial community structure were followed using culture-independent molecular method (terminal restriction fragment length polymorphism, T-RFLP) and by the cultivation approach. 

Results and conclusions. Nitrification activity was not detectably influenced by addition of diclofenac, while the main change of the bacterial community structure was detected only at the end of incubation (after 41 days) when diclofenac was added to artificial wastewater as the only carbon source. Changes in community composition due to enrichment were also observed using cultivation approach. However, taxonomic affiliation of isolates did not match taxons identified by T-RFLP community profiling. Isolates obtained from inoculum activated sludge belonged to five genera: Comamonas, Arthrobacter, Acinetobacter, Citrobacter and Aeromonas, known for their potential to degrade aromatic compounds. However, only Pseudomonas species were isolated after the last enrichment step on minimal agar plates with diclofenac added as the sole carbon source. 

Novelty and scientific contribution. Our results suggested that the selected recalcitrant and commonly detected pharmaceutical does not strongly influence the sensitive and important nitrification process of wastewater treatment neither. Moreover, the isolated strains obtained after enrichment procedure that were able to grow on minimal agar plates with diclofenac added as the only carbon source could serve as potential model bacteria to study bacterial diclofenac degradation.

*Corresponding author: +38613203410
  +38612573390
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getpdf NLM PubMed Logo https://doi.org/10.17113/ftb.58.04.20.6657  Supplement 

Antioxidant Capacity of Proteins and Hydrolysates from the Liver of Newborn Piglets, and Their Inhibitory Effects on Steatosis in vitro

Ruilin Zhangorcid tiny, Lasheng Yinorcid tiny, Jian Chenorcid tiny and Xuewu Zhang*orcid tiny

College of Food Science and Engineering, South China University of Technology, 510640 Guangzhou, PR China

 

Article history:

Received: 7 February 2020

Accepted: 22 December 2020

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Key words:

newborn piglet liver, protein hydrolysates, antioxidant activity, oleic acid, lipid accumulation

Summary:

Research background. Non-alcoholic steatohepatitis is a potentially progressive hepatic disorder that can lead to end-stage liver disease and hepatocellular carcinoma. The inhibitory effects of proteins and hydrolysates from the liver of newborn piglets on hepatic steatosis in oleic-acid-induced HepG2 cells were investigated in vitro.

Experimental approach. The extracted proteins from the liver of newborn piglets (NPLP) were hydrolysed with papain, pepsin, trypsin and Alcalase. Based on comparison of different enzyme digestion condition, a protein hydrolysis protocol was established to obtain hydrolysates with lipid-lowering effect.

Results and conclusions. PLH-trypsin (trypsin-digested NPLP hydrolysate) exhibited strong antioxidant activity and possessed good inhibitory effects on lipogenesis and cholesterol accumulation in HepG2 cells at 150 μg/mL, with a triglyceride decrease of (43±3) % and cholesterol decrease of (31±5) %, comparing with 0.75 mM oleic acid induced model. The addition of NPLH-trypsin (300 μg/mL) decreased alanine aminotransferase and aspartate aminotransferase activities and increased superoxide dismutase activity.

Novelty and scientific contribution. This study demonstrated that NPLH-trypsin have a potential preventive effect on NAFLD in its early stage, and NPLH-trypsin has potential use as the modulator of lipid overaccumulation disease in food supplements.

*Corresponding author: +86 20 87113848
  +86 20 87113848
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getpdf NLM PubMed Logo https://doi.org/10.17113/ftb.58.04.20.6634  

Immunomodulatory Activity in vitro and in vivo of Polysaccharides from Kabuli Chickpea (Cicer arietinum L.) Hull

Hafiz Muhammad Saleem Akhtarorcid tiny, Zipeng Yeorcid tiny, Mohamed Abdinorcid tiny, Yahya Saud Hamedorcid tiny, Guijie Chenorcid tiny and Xiaoxiong Zeng*orcid tiny

College of Food Science and Technology, Nanjing Agricultural University, Weigang 1, 210095 Nanjing, PR China

 

Article history:

Received: 14 January 2020

Accepted: 2 November 2020

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Key words:

Cicer arietinum L. hull, polysaccharide fractions, immunomodulatory activity, in vitro and in vivo activity, functional food

Summary:

Research background. Polysaccharides isolated from plants, fungi and bacteria are associated with immunomodulatory effects. Chickpea hull, which is regarded as food industrial waste, contains considerable amounts of antioxidants and bioactive compounds.

Experimental approach. In the present study, we investigated the immunomodulatory activity of polysaccharides from kabuli chickpea (Cicer arietinum L.) hull (CHPS). In vitro study was conducted with RAW264.7 cell line while in vivo study was carried out using specific pathogen-free BALB/c mouse animal model.

Results and conclusions. In in vitro test with RAW264.7 murine macrophage cells, the three purified fractions of chickpea hull polysaccharides showed potent immunomodulatory activity. Sample CHPS-3 showed stronger effect on cell viability, promoted the phagocytosis index to a greater extent and had the best effect on acid phosphatase activity. Moreover, it was found that CHPS-3 significantly (p<0.05) enhanced the secretion of nitrogen monoxide and cytokine (interleukins IL-6, IL-1β and tumour necrosis factor-alpha (TNF-α)) levels. In in vivo study, CHPS-3 improved thymus and spleen indices in cyclophosphamide-induced immunodeficient mice. Increased activities of lysozyme, catalase, superoxide dismutase and glutathione peroxidase, serum haemolysin content and total antioxidant capacity were observed, while the amount of malondialdehyde in the liver decreased.

Novelty and scientific contribution. The results suggest that chickpea hull polysaccharides enhanced the immune activity and could be developed as the ingredient of functional foods.

*Corresponding author: +862584396791
  +862584396791
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