Development of Lactobacillus acidophilus-fermented milk fortified with date extract

Approaches to Enhance Sugar Content in Foods: Is the Date Palm Fruit a Natural Alternative to Sweeteners?

The current levels of added sugars in processed foods impact dental health and contribute to a range of chronic non-communicable diseases, such as overweight, obesity, metabolic syndrome, type 2 diabetes, and cardiovascular diseases. This review presents sugars and sweeteners used in food processing, the current possibility to replace added sugars, and highlights the benefits of using dates as a new natural, nutritious and healthy alternative to synthetic and non-nutritive sweeteners. In the context of environmental sustainability, palm groves afford a propitious habitat for a diverse array of animal species and assume a pivotal social role by contributing to the provisioning of sustenance and livelihoods for local communities. The available literature shows the date as an alternative to added sugars due to its composition in macro and micronutrients, especially in bioactive components (fiber, polyphenols and minerals). Therefore, dates are presented as a health promoter and a preventative for certain diseases with the consequent added value. The use of damaged or unmarketable dates, due to its limited shelf life, can reduce losses and improve the sustainability of date palm cultivation. This review shows the potential use dates, date by-products and second quality dates as sugar substitutes in the production of sweet and healthier foods, in line with broader sustainability objectives and circular economy principles.

In Vitro Inhibition of α-Amylase, α-Glucosidase and Antioxidant Activity of Milk Containing Fenugreek Seed Alcoholic Extract

The aim of this study was to evaluate the effect of fenugreek seed alcoholic extract (FSAE) at the levels of 0.15% and 0.30% (V/V) on the selected properties of enriched milk during the 10-day storage period at 4 °C. The results demonstrated that with the addition of FSAE, the pH, brightness intensity and white color coefficient decreased and the values of acidity, viscosity, a* and b* indexes, total phenol content (TPC), total flavonoid content (TFC), antioxidant activity (AA) and enzyme inhibitory activity of enriched milk samples increased significantly compared to the control (p < 0.05). During the storage period, a decrease in TPC, TFC, AA and inhibitory activity was observed in all samples (p < 0.05). The FSAE was able to significantly reduce total microbial count (TMC) in milk samples (p < 0.05). In terms of sensory characteristics, the best sensory scores during the storage period were related to the sample containing 0.15% (V/V) FSAE. Overall, a positive and direct relationship was found between the beneficial effects of FSAE and its concentration. Finally, according to the results of the overall acceptance score in sensory tests, the sample containing 0.15% (V/V) FSAE was introduced as the best sample.

Effects of Freeze-Dried Banana and Watermelon Peel Powders on Bile Salt Resistance, Growth Kinetics, and Survival of Probiotic Bacteria

Fruit peels have potential as prebiotic sources thanks to their dietary fiber contents. This study aimed to determine the effects of freeze-dried banana (BPP) and watermelon (WPP) peel powders on bile salt resistance, growth kinetics, and survival of Lactobacillus acidophilus and Lactiplantibacillus plantarum. In the presence of 0.5-1% bile salt, L. plantarum counts were 0.52-1.13 log CFU/mL higher in MRS broth added with 5% peel powder than without peel powder. Lactobacillus acidophilus population was 2.47-2.79 log CFU/mL higher in MRS broth added with 5% peel powder than without peel powder in the presence of 0.5% bile salt. Both peel powders did not affect the growth kinetics of L. acidophilus in milk. Conversely, the growth of L. plantarum was promoted in milk supplemented with peel powders and yielded a shorter generation time (P < 0.05). The maximum population density of L. plantarum in milk supplemented with BPP (8.68 log CFU/mL) was higher than in milk without peel powder (7.72 log CFU/mL; P < 0.05). Survival of L. acidophilus improved during storage at 4 °C in milk added with peel powders. The results suggest that BPP and WPP can be functional ingredients in probiotic foods and may be used to improve the growth and survival of probiotic cultures.

Strategies for the Valorization of Date Fruit and Its Co-Products: A New Ingredient in the Development of Value-Added Foods

Date palm trees (Phoenix dactylifera L.) are traditionally cultivated in South-West Asia and North Africa for date fruit consumption, although in recent years, its consumption has increased worldwide, and its cultivation has spread to other areas of America, sub-Saharan Africa, Oceania, and Southern Europe. During date fruit processing, several types of by-products are generated, such as low-quality dates or seeds, which along with date fruit, represent an excellent source of dietary fiber and bioactive compounds such as flavonoids, tannins, carotenoids, tocopherols, and tocotrienols. Therefore, this review provides information on the processing of dates fruit and the value-added by-products generated from them as well as their applications in different types of foods for the development of foods with an enhanced nutritional and functional profile. The incorporation of date fruit and their co-products in food formulations will help to cover the current consumer demands for foods made with ingredients of natural origin and with health properties beyond the merely nutritional.

Development of fortified probiotic dairy desserts with added date extract, whey protein, inulin, folic acid, vitamin D and calcium

This study aimed to develop fortified dairy desserts containing Lactobacillus casei and evaluate the physicochemical, sensory, and microbiological characteristics of the product during 28 days of storage. Seven dairy desserts were formulated by date extract (8%), whey protein (1.56%), inulin (4%(, folic acid (0.00066%), vitamin D (0.002%) and gluconate calcium (0.66%). The addition of date extract and inulin increased total solids while whey protein incorporation into dairy desserts led to the improvement of protein and phosphorous content. Furthermore, all fortified dairy desserts showed higher antioxidant activity and total phenolic content. Fortification of dairy desserts had no negative effect on the sensory acceptability and syneresis was not observed. In addition, the pH reduction and increased acidity did not adversely affect the count of L. casei, which remained above 8 log CFU g-1 during storage. Consequently, the fortified dairy dessert developed in this research is an innovative food product with good acceptability and high nutritional quality.

Investigating the Effect of Probiotics as Natural Preservatives on the Microbial and Physicochemical Properties of Yogurt-Marinated Chicken Fillets

Microbial flora of probiotic yogurt can have nutraceutical properties and improve beneficial health effects of food products. In this study, microbial and physicochemical properties of raw chicken fillets dipped in regular yogurt and probiotic yogurt containing Lactobacillus casei, preserved at 4°C for 9 days, were studied. In this regard, microbial analysis (Staphylococcus aureus, fecal coliform, yeasts, and molds) and physicochemical analysis (pH, water holding capacity, cooking loss percentage, Thiobarbituric acid reactive substances, and texture profile analysis) were performed during the storage time. In comparison with control samples, the amount of Staphylococcus aureus, fecal coliforms, yeast and mold counts, pH index, malondialdehyde value, and cooking loss percentage reduced significantly ( $P<0.05$ ) in the chicken fillets treated with regular and probiotic yogurt, while the water holding capacity increased in six days. It was concluded that probiotic and regular yogurts reduced microbial growth and improved the physicochemical quality of chicken fillets during storage and cooking time.

Physicochemical, Microbiological, and Sensorial Quality Attributes of a Fermented Milk Drink (Laban) Fortified with Date Syrup (Dibs) during Cold Storage

This study investigated the nutritional, microbial, and sensory quality attributes of a fermented milk (laban) drink flavored with date syrup (dibs) during cold storage at 4 °C for 7 days. Date syrup was added to laban in specific proportions (2.5, 5, 7.5, 10, 12.5, and 15% date syrup/total weight of flavored laban) and an appropriate percentage (12.5%, 74 °Bx) was selected based on the sensory preference of panelists. The results indicate that flavoring laban with date syrup affected the physicochemical, nutritional, microbial, and sensory quality attributes of the product in different ways. Incorporation of date syrup in fresh laban drink significantly increased the pH, ash, protein, total solids, sugars, and magnesium (p < 0.05). However, acidity, fat, casein, lactose, calcium, total microbial count, and total yeast and molds count were decreased (p < 0.05). During storage, acidity, ash, and microbial load were concomitantly increased, while fat, casein, total solids, and sugars showed a concurrent reduction as the storage period progressed. The panelists preferred the freshly prepared flavored laban drink compared with the stored one, which is not surprising. After 7 days of storage, flavored laban drink was more acceptable than a non-flavored one. The findings of this research will help in fortifying dairy products with dates to create highly nutritious drinks without the addition of artificial additives, refined sweeteners, and preservatives, which at the same time would be accepted by consumers.

Influence of guabiroba pulp (campomanesia xanthocarpa o. berg) added to fermented milk on probiotic survival under in vitro simulated gastrointestinal conditions

In fermented milks inoculated with two thermophilic strains (Lactobacillus bulgaricus and Streptococcus thermophilus), guabiroba pulp (Campomanesia xanthocarpa O. Berg) was added in different concentrations: 5% (I5 sample) and 10% (I10 sample), compared to a control sample, with no pulp addition. In these fermented milks, Bifidobacterium BB-12 was added and the samples were submitted to a progressive gastrointestinal simulation in vitro. The cells count was performed, including the survival rates for all the progressive steps of the simulated digestion. Total phenolic content (TPC) and antioxidant activity analysis by FRAP (Ferric Reducing Antioxidant Power) and DPPH (2,2-diphenyl-1-picrylhydrazyl) were performed in all the gastrointestinal steps. Before and during the entire gastrointestinal tract, the Bifidobacterium BB-12 count was 8-9 log CFU g^-1, above the recommended for a probiotic product, with a highlight in intestinal colon steps. The I10 sample showed the highest viable cell count, the highest total phenolic content and antioxidant activity throughout the entire gastric steps (p < 0.05). The fermented milk proved to be an effective matrix for the probiotic stability and incorporation of guabiroba components. Bioactive compounds present in the guabiroba pulp may have occasioned a prebiotic and protective effect on Bifidobacterium BB-12 after gastric conditions. The possible bioconversion of these compounds in more active forms can contribute to the absorption in epithelial cells, enhancing fermented milks with guabiroba pulp as important sources of dietary accessible bioactive compounds.

Fermented milk: The most popular probiotic food carrier

Fermented milks are extensively produced and consumed all around the world. The production of these products is an old process that was used for extending the shelf life of milk. Nowadays, numerous traditional and industrial fermented milks with various texture and aroma can be found as an important part of human diet that exhibit several health benefits. In recent years, consumers' awareness about the effect of diet on health and tendency for consuming healthful food products directed manufacturers to develop functional foods. In this context, production of probiotic food products is a common approach. Fermented milks are suitable carrier for probiotics and their production and consumption can be a beneficial way for improving health status. For development of probiotic fermented milks, probiotic viability during fermentation and storage time, their interaction with starter cultures in the product as well as their effect on sensory properties of the product should be taken into account. This chapter describes different fermented milks, probiotics used in fermented milks, process of their production and quality aspects associated with these products.

Safety Assessment and Preliminary In Vitro Evaluation of Probiotic Potential of Lactococcus lactis Strains Naturally Present in Raw and Fermented Milk

The present study was conducted to find the potential of Lactococcus lactis strains naturally present in raw and fermented milk as probiotics and to evaluate their safety and some technological characteristics. There are numerous studies that evaluated probiotic properties of lactococci, nevertheless, limited studies on the probiotic potential of lactococci isolated from raw milk or dairy products were performed. Strains isolation from raw milk or dairy products and their characterization is important when selection of starter strains for the production of functional dairy foods is performed. Depending on aroma production and acidifying activity, 33 L. lactis strains were selected out of 169 and evaluated for safety, technological and probiotic properties. These strains were screened for antibiotic sensitivity, enzymatic activity, hemolytic and gelatinase activities. The strains were also assessed for resistance to bile salts and acid, growth in bile acids and cholesterol, cell surface hydrophobicity. Based on the obtained results, two strains with the best probiotic potential were selected. These two L. lactis strains, with 51% and 67% survival at low pH and more than 80% resistance to various bile salt concentrations, proved their resistance in vitro to gastric conditions. Also these strains proved to be good acidifiers (the pH of milk was reduced by at least 1 unit in 6 h at 30-37 °C) and can be used in the development of functional dairy foods as starter cultures.