Czech Journal of Food Sciences - In Press
Current trends and future perspectives in dairy by-product valorizationReview
Aslıhan Tüğen
The increase in milk production and demand for dairy products in the world has led to the emergence of a wide variety of products in the sector, while a high volume of solid (sludge) and liquid waste is also generated. Dairy industry wastes; due to their high organic load (BOD, COD), high moisture content and variable composition, can cause significant environmental and economic problems when they are intended to be disposed of directly. The aim of the research is to determine current methods and possible future trends for the evaluation of dairy industry by-products (whey, casein and lactose-containing wastes, wastewater and sewage sludge, etc.). Within the scope of the research, literature from 2010-2025 was scanned in databases such as Web of Science, Researchgate, ScienceDirect, PubMed and Google Scholar and systematically conducted in line with the PRISMA guide and a total of 34 documents were examined. According to the results, various technologies aimed at conversion into valuable products (valorization) and integration into the circular economy have come to the fore. Thermochemical methods such as hydrothermal carbonization (HTC), hydrothermal liquidation (HTL), pyrolysis and gasification are used to increase energy and chemical substance recovery in wastes with high moisture content. Products such as biochar, bio-oil and synthesis gas obtained in these processes have the potential to be evaluated as fuel, fertilizer or chemical raw material. On the other hand, thanks to biological methods (anaerobic and aerobic digestion, composting, microbial fermentation etc.), value-added products such as biogas, compost, bioplastic, single cell protein (SCP) can be obtained from dairy industry wastes; at the same time, waste volume and environmental impact are reduced. In addition to these findings, since it is difficult to use a single method in the evaluation of by-products, the necessity of using integrated systems that combine both thermochemical and biological approaches emerges in the literature. As a result, integrated systems bring together goals such as sustainability, economic profitability and environmentally friendly production in waste management and show that they are an effective solution for improving the energy, resource use and environmental performance of the sector.
Production and quality assessment of fig wine: a comparative study on Turkish fig varietiesOriginal Paper
Ziya Binat, Ayşegül Kırca-Toklucu
This study aimed to produce marketable fig wines from two main Turkish fig varieties (Sarilop and Bursa Siyahi) and evaluate their quality and acceptability. The fig musts were prepared at two Brix levels (17 and 24 °Bx) using both dried and fresh Sarilop (yellow-colored) and fresh Bursa Siyahi (dark purple-colored) figs. The total phenolic content of fig wines ranged from 223.21 to 267.98 mg gallic acid/L, while the total antioxidant capacity varied from 3.73 to 4.42 µmol Trolox/100 mL (ABTS assay) and 35.09 to 69.30 µmol Trolox/100 mL (DPPH assay). Wines produced from fresh Bursa Siyahi figs exhibited the highest antioxidant activity. The fig variety and the type of fruit (fresh or dried) had a significant effect on the phenolic composition. Epicatechin and chlorogenic acid were predominant in wines produced from Bursa Siyahi fresh figs, whereas rutin was dominant in wines made from fresh Sarilop figs. Based on sensory evaluation, the fig wines produced from the musts with a Brix level of 24 were more appreciated and received higher scores than those from 17 Brix musts (p
Enhancing Labneh with Freeze-Dried Fruits or Fruit Flavours: Effects on Physicochemical, Microbiological, and Sensory PropertiesOriginal Paper
Bayram Çetin, Christina Rehagel, Ömer Akineden
The present study aimed to formulate a novel labneh variant containing freeze-dried fruit pieces or fruit flavour and to evaluate their influence on physicochemical properties, microbiological quality, and sensory acceptance during storage. For this purpose, fruit-piece labneh was prepared by incorporating 6% freeze-dried strawberry, blackberry, or kiwi pieces, while fruit-flavoured labneh was formulated by adding 0.01% colouring and 0.1% fruit flavour derived from strawberry, blackberry, or kiwi juice. The labneh variants developed in this study were subjected to an additional post-fermentation pasteurisation followed by hot filling. Samples were analysed on days 1, 7, 15, and 30 of storage for selected physicochemical, microbiological and sensory parameters. Compared to plain labneh, fruit-piece samples showed an increased dry matter content, except for those containing kiwi. Conversely, water activity and fat content decreased, and variations in titratable acidity and pH were influenced by the type of fruit added. Microbiological analyses based on classical indicator microorganisms revealed low levels of total aerobic mesophilic bacteria in the range of 1.5 × 10^1 to 8.1 × 10^1 CFU/g. Enterobacteriaceae, Escherichia coli, yeasts and moulds were not detected, indicating good product safety. Notably, structural defects such as syneresis and increased bitterness were determined in kiwi-piece samples during storage. Sensory evaluation indicated that strawberry-flavoured, blackberry-flavoured, and strawberry-piece labneh were the most preferred by panellists. Overall, fruit- or flavour-enriched labneh produced with an additional post-fermentation heat treatment represents an attractive option for product diversification in the dairy industry. Based on their satisfactory safety, good microbiological stability and high sensory acceptance, these variants offer strong potential for industrial application.
Impact of Microencapsulation and Milk Matrix on L. acidophilus Survival in Yogurt-Based Ice Creams
Feray İnci MADEN, Prof.Dr. Salih ÖZDEMİR
This study evaluated the viability of Lactobacillus acidophilus ATCC 4356 in yogurt ice cream produced from cow and buffalo milk using both free and encapsulated probiotic forms, with or without inulin. Alginate-based microencapsulation was applied, and the samples were analyzed over a 60-day storage period. Ten different formulations were tested at four time points (days 1, 15, 30, and 60) for microbial counts and physico-chemical parameters. The highest L. acidophilus counts (5.91 and 5.97 log CFU/g) were recorded in buffalo milk-based samples containing encapsulated probiotics and inulin, while control samples made from cow milk showed the lowest TAMB (6.73 log CFU/g) and L. acidophilus (5.23 log CFU/g) counts. Encapsulation was found to significantly improve probiotic stability compared to free cells, especially in buffalo milk matrices. Yeast and mold counts remained below 2.00 log CFU/g after 30 days in most encapsulated formulations. Additionally, pH decreased and titratable acidity increased during storage. Ice cream samples with encapsulated probiotics exhibited longer melting resistance and higher viscosity values. These findings support the use of microencapsulation -particularly in buffalo milk- as an effective strategy to enhance probiotic viability and functional quality in frozen dairy systems.
Study on the Browning Mechanism of Apple Juice Based on Untargeted MetabolomicsOriginal Paper
Junpeng Bao, Mengyi Li, Ziwei Liu, Shuhui Zhang, Longying Pei, Qiuru Yin, Gelin Lü, Litao Zhang, Heng Zhang, Jianli Ding, Jia Li
Browning of apple juice is a major quality defect that occurs during storage, yet the molecular basis of the browning process remains unclear. This study utilized an untargeted metabolomics approach to investigate the untargeted metabolomic differences in Xinjiang Aksu sugarheart apple juice before and after 100 days of storage. Employing high-resolution LC-QTOF/MS, we identified 6264 metabolites, with 1588 significantly upregulated and 1158 downregulated. Multivariate statistical analysis, including PCA and OPLS-DA, revealed that storage time was the primary factor affecting metabolic differences (PCA1: 55.54%; OPLS-DA Q²Y = 0.971). Key findings suggest that browning is triggered by enzyme activation through tyrosine metabolism activation (substrate supply) and dopaquinone accumulation. Changes in transmembrane transport by ABC transporters also contribute to this process. Non-enzymatic browning is exacerbated by Maillard intermediate products and lipid peroxidation products. Simultaneously, disrupted glutathione metabolism and antioxidant system failure lead to redox imbalance. KEGG enrichment analysis indicated coordinated changes in phenylpropanoid biosynthesis (secondary metabolic polymerization), alkaloid metabolism, and the pentose phosphate pathways. These results suggest that oxidative stress, cell membrane damage, and polyphenol metabolism disturbances are key drivers of apple juice browning, offering a molecular foundation for quality control (QC) in apple juice production.
Artichoke as a Novel Substrate for Kombucha Fermentation: Fermentation Characteristics, Functional Properties, and Sensory EvaluationOriginal Paper
Anh Duy Do, Xuyen Le Bao Nguyen, Hong Viet La, Thach Phan Van
This study examined the feasibility of using artichoke (Cynara scolymus L.) as a non-traditional substrate for kombucha fermentation and evaluated its effects on fermentation performance, functional properties, and sensory quality. Fermentation with artichoke supported pronounced SCOBY development by day 21, alongside progressive sugar utilisation, acetic acid accumulation, and a concomitant decrease in pH. Total phenolic and flavonoid contents increased significantly during fermentation, reaching peak values at day 14 (342.47 ± 16.89 mg GAE L⁻¹ and 44.54 ± 3.35 mg QE L⁻¹, respectively), which coincided with enhanced antioxidant activity as assessed by DPPH and ABTS assays. The fermented beverage also demonstrated antibacterial activity against Escherichia coli, Salmonella typhi, Vibrio cholerae, and Staphylococcus aureus, together with moderate α-amylase inhibitory activity. Sensory evaluation showed higher overall acceptability for artichoke-based kombucha compared with the conventional tea-based formulation. Collectively, these findings indicate that artichoke can be effectively utilised as a substrate for kombucha fermentation, resulting in a beverage with enhanced functional properties and favourable sensory quality.