The Annals of the University Dunarea de Jos of Galati. Fascicle VI - Food Technology

Antimicrobial activity of lactic acid bacteria isolated from spontaneous sourdough based on ecological flours

Alina Alexandra Dobre — 2025-10-27

This study aimed to isolate and identify lactic acid bacteria (LAB) strains from spontaneously fermented sourdoughs prepared from different ecological flour types: einkorn wheat, corn flour, and rye flour, manufactured according to the traditional type I sourdough protocol. The study also evaluated their antibacterial and antifungal properties, which are key properties for industrial applications. Twenty LAB strains were isolated, and eight strains were identified to the species level using a semi-automated Biolog® Microbial Identification System. Three isolates (Lactobacillus brevis LM6, Lactobacillus fermentum LM3, and Lactobacillus coryniformis subs. coryniformis LM8) demonstrated versatile carbohydrate metabolism by producing gas when grown at 30 °C, thus revealing their heterofermentative characteristics. The strains were tested for antimicrobial properties using the agar well diffusion method against pathogenic bacteria Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Bacillus spizizenii. Most LAB strains exhibited antibacterial activity against the test microorganisms, particularly against B. spizizenii. The antifungal effects of LAB strains against Aspergillus brasiliensis, Penicillium crysogenum, and Mucor racemosus were also investigated. Only four LAB strains showed an inhibitory effect on the growth and development of fungi. P. chrysogenum was the most susceptible to the action of LAB strains, especially L. plantarum LM2, P. acidilactici LM5, and L. coryniformis LM8. These results revealed that LAB isolated from the spontaneous sourdough have promising antimicrobial and antifungal properties, making the ecological flour sourdough a good source of LAB with high potential to be used for obtaining single or mixted starter cultures.

Effect of processing variables on some quality attributes of soft unripened cheese produced from white Fulani cattle milk

Mosope Oluwaseyi Oyerinde — 2025-10-27

This study investigated the effect of processing variables on the quality attributes of soft unripened cheese from white Fulani cattle milk. Response surface methodology based on Box-Behnken design was used in the cheese processing and investigation of the effect of processing variables (boiling temperature, 60-80 ºC; coagulation time, 20-30 min and coagulant volume, 4-6 mL) on soft unripened cheese. The yield, colour (lightness, greenness, and yellowness) and physicochemical properties (pH and total titratable acidity (TTA)), proximate and mineral composition of soft unripened cheese samples were determined using standard methods. The textural (hardness, adhesiveness, cohesiveness, and gumminess) and sensory properties of the samples were also determined. Data were subjected to the analysis of variance and means were separated using Duncan’s multiple range test. The yield, moisture, total ash, crude protein, crude fat, crude fibre and total carbohydrate contents of soft unripened cheese samples ranged from 24.90 to 38.84%, 50.04 to 61.13%, 5.46 to 6.61%, 13.04 to 20.82%, 19.02 to 28.38%, 1.78 to 2.69% and 0.95 to 1.64%, respectively. The pH and TTA of soft unripened cheese samples were significantly (p<0.05) affected by the boiling temperature, coagulation time and coagulant volume. The increase in the boiling temperature and coagulation time at constant coagulant volume increased the mineral contents of soft unripened cheese. The increase in coagulation time and coagulant volume significantly (p<0.05) decreased the textural properties of soft unripened cheese. However, soft unripened cheese can be processed at the processing condition of 80 ºC boiling temperature, 25 min coagulation time and 4 mL coagulant volume.

Optimizing cold pressed virgin coconut oil extraction: yield improvement and functional potential of coconut meal valorization

Adhitya Yudha Pradhana — 2025-10-27

Virgin Coconut Oil (VCO) is an unrefined oil extracted from fresh coconut kernel without chemical additives, typically using a cold-press method that also yields Virgin Coconut Meal (VCM) as a by-product. This study aimed to optimize the yield and quality of both VCO and VCM. Coconut (Cocos nucifera L.) types of Tall, Hybrid, and Dwarf varieties were screened to identify the one with the highest VCO yield and the lowest meal yield. The cold press technique combined with the response surface methodology (RSM) was employed for optimization. The Mapanget Tall coconut (MTT) showed the highest VCO yield (23.81%), the lowest meal yield (27.43%), and water evaporation (47.38%). Optimization yielded a VCO yield of 28.83% under ideal processing conditions, meal yield of 26.51%, and water evaporation of 46.42%. The major fatty acid in the VCO was the lauric acid (48.50%), meeting International Coconut Community standards. VCM composition included 9.15% moisture, 33.40% carbohydrates, 20.95% fat, 14.51% protein, 17.14% crude fiber, and 4.84% ash. These results highlight the potential of valorization of VCM as a functional food ingredient, particularly for its use in coconut-based skim milk beverages and other nutraceutical formulations.

Impact of different vacuum oven drying temperature on the chemical, physical, and microbial characteristics of a dried probiotic yogurt product during cold storage

Fatimah Eesee Jaafar — 2025-10-27

The objective of this research was to prolong the storage life of probiotic yogurt and facilitate its handling and transportation, in addition to preserving the physicochemical characteristics and vitality of probiotic bacteria within the permissible ranges, during storage periods. The results showed the possibility of preserving probiotic yogurt dried at three different temperatures of 40, 50, and 60 °C and pressures of 0.5 millibars to maintain its physical and chemical characteristics within acceptable ranges. The number of bacteria decreased during the storage period, but the number of bacteria that enabled them to perform their therapeutic function remained maintained. The moisture, protein, fat, carbohydrate, ash contents, pH levels, and total acidity of probiotic yogurt of 4 %, 30.01%, 1.4%,5 4.68%, 7.89%, 4.2, and 1.1%, respectively, were within acceptable ranges at different temperatures and storage periods. Several tests were conducted on dried yogurt samples, including X-ray diffraction, electron microscopy, and thermal analysis. This demonstrated the extent of the effect of temperature and the drying process on the structure of dried probiotic yogurt after reconstitution and the extent of its effect on the bonding of the yogurt components with each other.

Replacing unhealthy sugars in chewable candy: the use of honey and stevia as natural sweeteners in chrysanthemum-based gummy candy

Wimala Hardyawati Putri Apsari — 2025-10-27

Chewable candies are a major contributor to added sugar intake, particularly among children, and excessive consumption of such products is associated with adverse health outcomes. This study aimed to formulate a Chrysanthemum-based gummy formula with reduced sugar content and to evaluate the antioxidant activities of Indonesian forest honey. The antioxidant activities of Multiflora, Rain Forest, and Manuka honey were evaluated using the DPPH radical scavenging assay. The honey variant demonstrating the highest antioxidant activity was incorporated into the gummy formulation in combination with stevia. The resulting gummy candies were evaluated for their texture profile, hedonic test, and color measurement. Results indicated that Multiflora honey exhibited superior antioxidant activity compared to Rain Forest honey. The optimal formulation for sucrose replacement comprised 33.12% Multiflora honey and 2.59% stevia. The findings suggest that a combination of Multiflora honey and stevia is a viable alternative to sucrose in gummy candy production. The potent antioxidant activity of Chrysanthemum, along with the reduced sugar content, supports the potential development of this formulation into a child-friendly nutraceutical product.

Physicochemical characterisation of two Japanese plum (Prunus salicina Lindl.) cultivars grown in South-Western Romania

Cristina Paula Săpoi (Gheorghe) — 2025-10-27

In the present study, two Japanese plum (Prunus salicina Lindl.) cultivars grown in a collection orchard in Oltenia (South-Western Romania), namely Eldorado and Methley, were evaluated for their geometrical, physical, nutritional and antioxidant properties. In addition, phenolic compounds, organic acids and vitamin C contents were determined by high-performance liquid chromatography in fruit flesh and peel. Methley had larger fruits with higher pulp ratio as compared with Eldorado, however Methley plums had lower dry matter, soluble solids content and titratable acidity. Total phenolic content was higher in Eldorado plums as compared with Methley plums, both in fruit flesh (143.82 mg/100 g and 129.27 mg/100 g, respectively) and peel (572.14 mg/100 g and 536.44 mg/100 g, respectively). The analysis of phenolic compounds indicated that rutin was the dominant flavonoid in the peel of both cultivars (76.10 mg/100 g in Methley and 51.63 mg/100 g in Eldorado), followed by epicatechin or catechin hydrate, depending on cultivar. Chlorogenic acid was the major phenolic acid in flesh, its content was higher in the flesh of Methley plums (2.31 mg/100 g) as compared with Eldorado (1.79 mg/100 g). In terms of organic acids content, malic acid was predominant, followed by citric or tartaric acids, depending on cultivar. The nutritional and bioactive properties of Eldorado and Methley Japanese plum cultivars make them suitable to be grown in the agroecological conditions of South-Western Romania.

Glycerol-based NADES for bioactive compound extraction from Prunus spinosa L. fruit: formulation, characterization, and application

Asmaa Berkati — 2025-10-27

The objective of this study was to synthesize and evaluate three innovative Natural Deep Eutectic Solvents (NaDES) for their potential in extracting bioactive compounds from blackthorn (Prunus spinosa L.). The NaDES solutions were synthesized by combining glycerol as a hydrogen bond acceptor with fructose to form N1, sucrose to form N2, and tartaric acid to form N3. The characterization involved pH, viscosity, and conductivity measurements, stability evaluations, and Fourier-transform infrared spectroscopy, with extraction efficiency compared against conventional 70% ethanol solvent. Evaluation criteria included total phenolic content, total flavonoid content, and antioxidant activity using the DPPH method. The characterization revealed significant variations in pH, viscosity, conductivity, and chemical structure, directly influenced by the type of hydrogen bond donor employed. Furthermore, TPC was highest in N1, reaching 9.28 mg GAE/g DW, followed by N3, N2, and 70% ethanol. Flavonoid yield peaked in N3 (3.26 mg CE/g DW), followed by N2, N1 and 70% ethanol. The hydroethanolic extract exhibited the highest antioxidant activity at 87.89%. LC-DAD analysis supported these quantification results. These findings underscore the potential of glycerol-based NaDES as a green, non-toxic alternative for extracting bioactive compounds positioning them as promising candidates for future applications in the food, cosmetics, and pharmaceutical industries.

Development and validation of an enzymatic method for the determination of citric acid in wines

Gianina Marian (Țoca) — 2025-10-27

Citric acid is a crucial element in wine, affecting its flavor, acidity, and overall quality. The main objective of this study was to develop and validate an enzymatic technique for quantifying citric acid in wine, as a basis for assessing wine quality. The technique uses specific enzymes to facilitate the transformation of the citric acid into measurable compounds, providing a precise and reliable approach for quantification. The performance of the method was assessed using several parameters to ascertain its precision, accuracy, and linearity over the range of citric acid concentrations commonly present in wine. The method was linear in the citric acid measurement range of 23 mg/L - 380 mg/L with a correlation coefficient R² of 0.9941. The limit of detection was determined to be 19 mg/L, while the limit of quantification was established at 37 mg/L. The recovery was in the range 92.29-103.66% while the relative standard deviation was less than 2%. The method was additionally evaluated against standard reference techniques, confirming its appropriateness for routine analysis in wine quality assessment. This enzymatic approach is a reliable and economical option for quantifying citric acid levels in wine, facilitating more accurate and efficient oversight of wine production operations.

Physicochemical properties and antioxidant activity of craft and commercial beers marketed in Romania

Livia Patrascu — 2025-10-27

Beer quality is determined by a multitude of physicochemical characteristics and bioactive properties, which influence not only the taste and appearance of the product, but also its functional potential on the consumer’s health. The present study aimed to determine the physicochemical properties and in vitro antioxidant activity of a total of 21 samples of different beer types, such as Lager, Australian Pale Ale, Indian Pale Ale, Amber, Double Amber Dark Lager, Black, Stout, and Porter. The physicochemical characteristics considered in the study were EBC color, pH, total titratable acidity, soluble proteins, and viscosity. The biological activity of the beer was assessed by determining the antioxidant activity as DPPH and ABTS radicals scavenging activity and the total phenolic content. Both DPPH and ABTS-based methods indicated that wheat beers presented the lowest in vitro antioxidant activity among all tested samples, while the highest value was registered for black beer types. Results showed that antioxidant activity parameters were correlated with the original extract declared by the producers, which varied from 10.6 to 16.8 °P. Beer color varied from 8.5 EBC units (blonde Pilsner) to 250 - 253 EBC units (dark beers such as Amber, Black, and Porter), with no correlation between antioxidant activity and color. Other important correlations were found between original extract and energy value, alcohol content, viscosity or total phenolic content.

Evaluation of antioxidant and in vitro anti-inflammatory activities of Hexalobus monopetalus (A. Rich.) Engl. Diels extracts

Severin Mbaihougadobe — 2025-10-27

Hexalobus monopetalus is a medicinal plant which grows in tropical Africa, whose chemical composition and biological properties are not yet fully known. It is traditionally used for alleviating gastric disorders, fevers and diabetes. Phytochemicals responsible for the biological activities are found in varying levels in many medicinal plants. This study aimed to evaluate various extracts from the roots of H. monopetalus from Chad, central Africa. Phenolic compounds were extracted by two methods, one being hydromethanolic (H₂O/MeOH) extraction and the second method an extraction with four solvents of increasing polarity: cyclohexane, dichloromethane, ethyl acetate, and methanol. The antioxidant capacity was determined by DPPH and ABTS methods. Total polyphenols were assessed by the Folin-Ciocalteu method, and also, the anti-inflammatory activity was estimated in vitro. Gas chromatography coupled with mass spectrometry (GC-MS) analysis showed that the cyclohexane extract contains a predominance of polycyclic sesquiterpenes, and other compounds such as alcohols and phenols, thus demonstrating the richness and chemical diversity of the extract. Polyphenol content was higher in the dichloromethane extract (523.53 mg EqQ/g). Total flavonoid content in the water-methanol extract (20:80 v/v) was 227.84 mg EqQ/g dry matter, 183.85 mg EqQ/g dry matter was found in the methanolic extract, and in the ethyl acetate extract there was 178.93 mg EqQ/g dry matter. The antioxidant and anti-inflammatory properties also varied depending on the extraction solvent. The hydromethanolic extract was the most active in all cases, while the dichloromethane extract showed less antioxidant activity.

Impact of edible grasshopper flour on the chemical and phytochemical composition of Ogi powder and the sensory acceptability of gruel

Wasiu Awoyale — 2025-10-27

Ogi is a traditional staple that is low in protein and high in carbs. It is often produced from cereal grains, including maize, millet, and sorghum. The incorporation of edible grasshopper flour may not only improve the protein quality of Ogi powder but also affect the chemical and phytochemical composition; hence, this research is necessary. The chemical and phytochemical compositions of Ogi powder samples produced from blends of sorghum Ogi powder (SOP) (50–100 g) and grasshopper flour (GF) (10–50 g) generated through Design Expert Software were analyzed via standard methods, with 100 g of SOP used as a control sample. Fifteen untrained panelists performed the sensory evaluation of the gruel. The results revealed that the mean chemical composition of the supplemented sorghum Ogi powder was moisture, 4.62%; fat, 2.16%; ash, 2.43%; protein, 20.56%; crude fibre, 0.92%; total carbohydrates, 69.32%; and energy value, 381.96 kcal/100 g. The mean mineral composition was iron, 2.96 mg/100 g; and zinc, 1.85 mg/100 g. The mean phytochemical composition was oxalate, 0.36 mg/100 g; phytate, 0.94 mg/100 g; and tannin, 0.36 mg/100 g. GF inclusion in the SOP reduced the carbohydrate content and increased the protein, ash, fat, crude fibre, zinc, iron, phytate, and tannin contents. All of the supplemented Ogi gruel samples had statistically identical tastes (except for 75 g SOP:30 g GF and 100 g SOP:10 g GF), appearances (apart from 50 g SOP:10 g GF and 50 g SOP:50 g GF), and overall acceptance (apart from 75 g SOP:30 g GF). Consequently, the risk of macro- and micronutrient deficits linked to the intake of cereal-based foods in developing nations may be reduced by adding GF to SOP.

Microalgae as a sustainable feed source and a bioremediation strategy for agro-industrial effluents

Saraswathy Balajinathan — 2025-10-27

Recently, microalgae have emerged as nutrient-dense feed sources with substantial benefits for animal health and productivity. They contain high-quality protein, essential fatty acids, vitamins, minerals, and bioactive compounds that help to improve the quality and quantity of animal-derived products, including milk, meat, and eggs, thereby presenting a sustainable alternative to conventional feed sources. Additionally, their immunomodulatory properties enhance gastrointestinal health, disease resistance, growth performance, and reproductive outcomes in livestock. Beyond animal nutrition, microalgae bio-actives hold value in cosmetics, pharmaceuticals, and nutraceuticals, showcasing their industrial versatility. Microalgae can grow in diverse environments, including wastewater and effluents. Wastewater has the potential to substitute synthetic media used in cultivation, providing nutrient-rich biomass that can serve as an alternative feed source. Cultivating microalgae in effluents/wastewater has emerged as a sustainable and eco-friendly approach for wastewater treatment and biomass production. However, high production costs and scalability constraints limit its widespread application. This review highlights the cultivation of microalgae using different wastewater sources as an alternative substrate and their nutritional value, as well as the health and environmental benefits of using it in animal feed. It also discusses the current challenges and examines the potential of microalgae to transform animal agriculture while contributing to a circular bioeconomy.

Influence of extraction methods on Ulvan water holding capacity and rheological properties: a systematic review

Suci Istiqlaal — 2025-10-27

Ulvan, a sulfated polysaccharide derived from green algae such as Ulva and Enteromorpha sp., possesses water-binding capability, making it a valuable natural hydrocolloid in the food sector. Physicochemical properties, such as water-holding capacity (WHC) and rheology, influence their use as thickeners, stabilizers, and gelling agents. Ulvan extraction methods, including hot water extraction (HWE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), enzymatic extraction (EAE), and chemical solvent extraction (CAE), have a substantial impact on these qualities. The purpose of this review is to investigate the effects of extraction procedures on the WHC and rheological properties of ulvan to maximize its use in food items. A systematic literature review (SLR) was conducted, which involved scanning publications in databases such as Google Scholar, Scopus, and ScienceDirect. According to the evaluation results, HWE and EAE retain a branched structure and high sulfate content, making them acceptable for applications requiring strong gel and high WHC. In contrast, the MAE, UAE, and CAE approaches generate linear ulvan that enhances viscosity at high concentrations. The use of UAE and EAE can improve monomer retention, although careful management is required to maintain the sulfate concentration and molecular weight.

Nano- and micro- encapsulation of curcumin by spray drying technique: characteristics and applications in food

Cristian Dima — 2025-10-27

Curcumin (CUR) is an important natural polyphenol, extracted from the rhizome of Curcuma Longa used for thousands of years by the Asian population, both as a food ingredient (dye, preservative, spice) and as a remedy for certain gastrointestinal diseases, inflammation, cataracts, and bacterial infections. Unfortunately, CUR, like many polyphenols, has a low bioavailability due to its low water solubility, chemical instability at pH variations, low cell absorption, and rapid metabolism. To overcome these challenges, many researchers have applied various CUR encapsulation techniques. In this study, an overview of the principles and conditions for nano/micro-encapsulation of CUR through the spray-drying has been presented. Different biopolymers including polysaccharides and proteins have been utilized for this purpose. For nanoencapsulation of CUR, an innovative spray-drying technique has recently been developed, the so-called nano-spray-dryer, whose operations and advantages are briefly discussed in this paper too. The results from the literature on the optimization of physico-chemical and technological parameters, the nature of encapsulating materials, and the characteristics of the spray-dried CUR-loaded powder particles are also highlighted. Finally, the applications of spray-dried CUR powders in food functionalization with the focusing on the antioxidant, antimicrobial, and coloring properties are described.