Effect of Rosemary (Rosmarinus officinalis L.) Supplementation on Probiotic Yoghurt: Physicochemical Properties, Microbial Content, and Sensory Attributes

Physicochemical, colour, microbiology, sensory and mineral attributes of set-type yoghurt produced from Gundelia tournefortii L. and its gum

The present study aimed to investigate the production of yoghurt in which the parts of the Gundelia tournefortii L. and its gum were added to milk at levels of 3% (v/v), incubated until the pH value reached 4.7 at 42 °C and then stored at 4 °C for 21 days. The Ca, P, K, Na and Mg contents of the yoghurt sample containing Gundelia tournefortii L. proved to be higher than those found in the control sample. Acidity, acetaldehyde, viscosity, a* values of yoghurt samples increased during storage, while the volatile fatty acids, gel firmness, whey separation, water holding capacity, L* and the b* values were decreased. The lactic acid bacteria count on the 21st day was > 6 log CFU/g in all yoghurt samples. The total aerobic mesophilic bacteria decreased except for the yoghurt sample containing Gundelia tournefortii L. milk, while the yeast and mold increased. The preference map revealed that 60-80% of consumers were satisfied with the control sample and the Gundelia tournefortii L. gum sample. Gundelia tournefortii L. milk and Gundelia tournefortii L. leaves samples were also found to have acceptable scores. As a result, adding Gundelia tournefortii L. into the yoghurt turned out to have a positive impact on its sensory and functional properties and could lead to an innovative approach in the dairy product market.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05987-1.

Rosemary: Unrevealing an old aromatic crop as a new source of promising functional food additive-A review

Rosemary (Rosmarinus officinalis L.) is one of the most famous spice plants belonging to the Lamiaceae family as a remarkably beautiful horticultural plant and economically agricultural crop. The essential oil of rosemary has been enthusiastically welcome in the whole world for hundreds of years. Now, it is wildly prevailing as a promising functional food additive for human health. More importantly, due to its significant aroma, food, and nutritional value, rosemary also plays an essential role in the food/feed additive and food packaging industries. Modern industrial development and fundamental scientific research have extensively revealed its unique phytochemical constituents with biologically meaningful activities, which closely related to diverse human health functions. In this review, we provide a comprehensively systematic perspective on rosemary by summarizing the structures of various pharmacological and nutritional components, biologically functional activities and their molecular regulatory networks required in food developments, and the recent advances in their applications in the food industry. Finally, the temporary limitations and future research trends regarding the development of rosemary components are also discussed and prospected. Hence, the review covering the fundamental research advances and developing prospects of rosemary is a desirable demand to facilitate their better understanding, and it will also serve as a reference to provide many insights for the future promotion of the research and development of functional foods related to rosemary.

Effect of the Addition of Selected Herbal Extracts on the Quality Characteristics of Flavored Cream and Butter

Herbs have been used for centuries in order to enrich food as preservatives, flavorings, and medicinal agents. The aim of this work was to study the effect of the addition of selected herbal extracts (dried leaves of Thymus vulgaris L., Origanum vulgare L., Satureja hortensis L., Rosmarinus officinalis L., and Ocimum basilicum L.) on selected parameters of fermented flavored cream (counts of starter culture bacteria and pH value) and the resulting flavored butter (water content, water distribution, butter plasma pH, butter fat acidity, and oxidative stability), preceded by a study of the activity of the herbal extracts against starter lactic acid bacteria determined using the well diffusion method. The extracts did not inhibit the starter lactic acid bacteria at a fixed level. The presence of the herbal extracts contributed to a shorter fermentation course and influenced the counts of starter culture bacteria during fermentation and refrigerated storage (at 5 °C) for 21 days. The extract additives did not affect the water content or the degree of its dispersion, the butter plasma pH, or the butter fat acidity. The positive effect of the rosemary and thyme extract addition was only noted when analyzing the oxidative stability of the milk fat of the butter.

Novel Probiotic/Bacterial Cellulose Biocatalyst for the Development of Functional Dairy Beverage

The development of innovative functional products with potential health benefits, under the concept of bio-economy, is flourishing. This study undertook an evaluation of non-dairy lactobacilli Lactiplantibacillus pentosus B329 and Lactiplantibacillus plantarum 820 as “ready to use” starter cultures. Lactic acid bacteria (LAB) cultures were evaluated for their fermentation efficiency, before and after freeze-drying, using cheese whey (CW) as a fermentation substrate and subsequent immobilization on bacteria cellulose (BC) to produce a novel biocatalyst. The biocatalyst was applied in functional sour milk production and compared with free cells via the assessment of physicochemical and microbiological properties and sensory evaluation. Evidently, LAB strains exhibited high fermentative activity before and after freeze-drying. Results of a 5-month storage stability test showed that viability was 19% enhanced by immobilization on BC, supporting the concept of “ready to use” cultures for the production of fermented beverages. Likewise, sour milk produced by the BC biocatalyst presented higher organoleptic scores, compared to the free cells case, whereas immobilization on BC enhanced probiotic viability during post-fermentation storage (4 °C, 28 days). The obtained high viability (>107 log cfu/g) demonstrated the efficacy of the proposed bioprocess for the production of functional/probiotic-rich beverages. Ultimately, this work presents a consolidated scheme that includes the advantages and the cooperative effect of probiotic LAB strains combined with a functional biopolymer (BC) towards the formulation of novel functional products that coincide with the pillars of food systems sustainability.

Using Rosemary Essential Oil as a Potential Natural Preservative during Stirred-like Yogurt Making

The popularity of rosemary has grown as a natural alternative over the synthetic supplements due to its potential health benefits. The rosemary plant has been utilized to preserve food due to its ability to prevent oxidation and microbial contamination. The reason for this study was to determine the phytochemical components and antimicrobial activity of rosemary essential oil (REO) and the effect of REO addition (0.5 and 0.7%) on the chemical, microbiological, and sensory properties of stirred-like yogurt (SLY) during 16 days of storage at 4 °C. The obtained data observed that REO exhibited antimicrobial action against Escherichia coli, Staphylococcus aureus, and Salmonella marcescens, as well as fungi (Aspergillus flavus) and yeasts (Candida albicans). Increased REO to 0.7% accelerated (p < 0.05) the development of lactic acid bacteria (LAB) in SLY (8.3 log cfu/g) and delayed yeast growth up to 12 days. Molds and coliforms were also not found in the SLY samples with REO. In comparison to control samples, sensory results showed that the addition of REO improves the overall acceptance of SLY (p < 0.05). In conclusion, the current study found that REO could be used as a natural preservative during the production of SLY to extend shelf-life and promote LAB development.

Impact of Incorporating the Aqueous Extract of Hawthorn (C. oxyanatha) Leaves on Yogurt Properties and Its Therapeutic Effects against Oxidative Stress Induced by Carbon Tetrachloride in Rats

The current study aimed to evaluate the chemical, phytochemical, and sensory properties; the nutritional value; and the antioxidant properties resulting from the incorporation of yogurt fortified with the aqueous extract of Hawthorn leaves in Sprague Dawley rats. The results revealed that the yogurt containing the aqueous extract from Hawthorn leaves exhibited no significant differences in terms of its protein, fat, and ash contents compared to control samples. Moreover, the highest total phenolic content (62.00 ± 1.70) and antioxidant activity (20.60 ± 0.74%) were detected in the yogurt containing 0.4% Hawthorn leaf extract compared to the other samples. The consumption of yogurt fortified with the aqueous extract from Hawthorn leaves by rats experiencing oxidative stress resulted in a significant decrease (p ≤ 0.05) in the triglyceride, total cholesterol, low-density lipoprotein, aspartate aminotransferase, alanine aminotransferase, creatinine, urea, and malondialdehyde levels and a remarkable increase (p ≤ 0.05) in the high-density lipoprotein, total protein, and albumin levels as well as in the total antioxidant potentials of serum compared to the positive control group, indicating that the extract from Hawthorn leaves can play a preventive role against oxidative stress. Collectively, our study concluded that the extract from Hawthorn leaves can provide health benefits to yogurt on the basis of its high bioactive components and can exert protective effects against oxidative stress in rats.

Effect of Supercritical Extract from Black Poplar and Basket Willow on the Quality of Natural and Probiotic Drinkable Yogurt

Yogurt is a fermented milk drink produced by Streptococcus thermophilus, Lactobacillus delbrüeckii ssp. bulgaricus, or Lactobacillus rhamnosus, which can be enriched with polyphenolic compounds to enhance its antioxidant properties. Supercritical (scCO2/H2O) extracts obtained from the mixture of bark and wood of black poplar (Populus nigra) and basket willow (Salix viminalis) are the source of bioactive compounds. The aim of the study was to assess the effect of supercritical extracts from the P. nigra and S. viminalis on the fermentation, quality, and bioactive properties of drinkable natural and probiotic yogurts. The incorporation of scCO2/H2O extracts at a dose of 0.01% (w/v) into milk for the production of natural and probiotic yogurts increases their functional properties by enhancing the antioxidant activity without causing negative effects on the physicochemical and organoleptic properties of products. The antioxidant activity of yogurt with scCO2/H2O extract from P. nigra and S. viminalis was higher than control yogurts by 1.3-13.2% and 4.4-37.5%, respectively. The addition of a supercritical S. viminalis extract reduced the time of natural and probiotic yogurt fermentation. Natural and probiotic yogurt with scCO2/H2O extracts added was characterised by a bacterial population size of over 7 log cfu/g, and the microflora was active throughout the cold storage period. FTIR analysis confirmed the presence of scCO2/H2O extracts from P. nigra or S. viminalis in both types of yogurt. A secondary structure analysis confirmed interactions between compounds of scCO2/H2O extract from P. nigra and S. viminalis extract with milk proteins. These interactions affect the compounds' structural and functional properties by changing, e.g., their digestibility and antioxidant properties.