Chilled milk-based desserts as emerging probiotic and prebiotic products

Probiotics in Functional Foods: Survival Assessment and Approaches for Improved Viability

Nowadays, food is no longer just for nutrition. Consumers are more demanding and expect to get health benefits from their daily meals. Various areas of the food industry are in great demand of functional chemicals to enhance the taste and nutritional value of their products. Probiotic bacteria have already been part of the human’s routine for good gut microbiota maintenance in terms of pharmaceutical products. Their incorporation in food however is a challenging task that offers great opportunities but has limitations as well. Specifically, the purpose of this review is to emphasize the importance of probiotics in food, to assess their survival through gastrointestinal tract, and to highlight the recent advances in approaches for their improved viability.

Non-fermented Dairy Desserts with Potentially Probiotic Autochthonous Lactobacilli and Products from Peel of Jabuticaba (Myrciaria cauliflora)

The influence of two autochthonous lactobacilli strains with probiotic potential (Lactobacillus mucosae CNPC007 and Lactobacillus plantarum CNPC020) in comparison to a commercially available probiotic strain (Lactobacillus rhamnosus LR32) in non-fermented dairy desserts added with ingredients (syrup and hydroethanolic extract) derived from jabuticaba (Myrciaria cauliflora) peels was investigated. L. mucosae showed the best survivability and stability of the studied lactobacilli after processing and during storage, respectively, and also remarkably influenced the texture and sensory features of desserts in comparison to the other strains; L. plantarum achieved viability comparable with the commercial probiotic, above 6 log cfu/g up to the 21st day of the products refrigerated storage. The hydroethanolic extract and syrup from the jabuticaba peel contributed to the phenolic content of the dairy desserts (around 30 mg GAE/100 g) that showed to be able to scavenge DPPH radicals (around 300 g dessert/g DPPH). The different lactobacilli strains did not significantly influence the antioxidant capacity parameters of the desserts (p > 0.05), although the desserts' color was not stable during storage and tended to reduce the acceptability scores of the three trials. Non-fermented dairy desserts with jabuticaba peel ingredients showed to be good sources of phenolic compounds with an antioxidant capacity, offering suitable conditions for the viability maintenance of the autochthonous lactobacilli cultures.

High-intensity ultrasound energy density: How different modes of application influence the quality parameters of a dairy beverage

This study evaluated the influence of the high-intensity ultrasound (HIUS) technology on the quality parameters of a model dairy beverage (chocolate whey beverage), operating under the same energy density (5000 J/mL), but applied at different ways. Two processes were performed varying nominal power and processing time: HIUS-A (160 W and 937 s), and HIUS-B (720 W and 208 s). Our objective was to understand how different modes of application of the same HIUS energy density could influence the microstructure, droplet size distribution, zeta potential, phase separation kinetic, color parameters and mineral profile of the chocolate whey beverage. The results demonstrated that the different modes of application of the same HIUS energy density directly influenced the final quality of the product, resulting in whey beverages with distinct physical and microstructural characteristics. The HIUS-B processing was characterized as a thermal processing, since the final processing temperature reached 71 °C, while the HIUS-A processing was a non-thermal process, reaching a final temperature of 34 °C. Moreover, HIUS-B process greatly reduced the droplet size and increased the lightness value in relation to the HIUS-A processing. Both treatments resulted in whey beverages with similar phase separation kinetics and were more stable than the untreated sample. The HIUS processes did not modify the mineral content profile. Overall, the study emphasizes the versatility of the HIUS technology, highlighting that the processing must not be based only on the applied energy density, since different powers and processing times produce dairy beverages with distinct characteristics.

Influence of co-cultures ofStreptococcus thermophilus and probiotic lactobacilli on quality and antioxidant capacity parameters of lactose-free fermented dairy beverages containingSyzygium cumini(L.) Skeels pulp

This study investigated the influence of probiotic lactobacilli in co-culture with Streptococcus thermophilus on composition, physicochemical parameters, microbial viability, sensory acceptability, antioxidant capacity and protein profile of lactose-free fermented dairy beverages with added whey, β-galactosidase and jambolan (Syzygium cumini (L.) Skeels) pulp. Three beverages (T1, T2 and T3) were prepared with Streptococcus thermophilus TA-40 as starter culture. Lactobacillus rhamnosus LR32 and Lactobacillus casei BGP93 probiotic cultures were added into T2 and T3, respectively. The probiotic adjuvants slightly influenced the pH and titratable acidity of dairy beverages, with no influence on the proximate composition and on the sensory attributes. Samples presented fat and protein contents suitable to meet the requirements of “low-fat dairy beverages with non-dairy ingredients added” according to the Brazilian legislation, lactobacilli viability above 7 log CFU g⁻¹ for both probiotics and total phenolic content around 40 mg GAE 100 g⁻¹. Colour was the most evaluated sensory aspect (average scores close or higher than 8 in a scale from 0 to 10 for most of the sampling periods). The overall antioxidant capacity increased significantly following the addition of jambolan (p < 0.05), and significantly more during storage (p < 0.05), likely due to proteolysis verified in the electrophoresis gels, as a result of the metabolism of the lactic cultures. The dairy beverages studied are good options for functional foods due to their nutritional value, viability of probiotic lactobacilli, phenolic content, and antioxidant capacity, also serving lactose-intolerant people.

Probiotic dairy beverages for lactose intolerants had lactobacilli viability above 7 log CFU for 21 days. The co-cultures studied showed proteolytic activity and reinforced the effect of the jambolan pulp on the antioxidant capacity of the products.

Fermented Dessert with Whey, Ingredients from the Peel of Jabuticaba (Myrciaria cauliflora) and an Indigenous Culture of Lactobacillus plantarum: Composition, Microbial Viability, Antioxidant Capacity and Sensory Features

The use of agro-industrial wastes in combination with indigenous lactic acid bacteria is an interesting option to confer functional potential to food products. The microbial viability, chemical composition, antioxidant capacity, texture and sensory acceptability of a fermented dairy dessert containing the indigenous culture Lactobacillus plantarum CNPC003, whey and ingredients obtained from the jabuticaba (Myrciaria cauliflora) peel were compared with formulations without lactobacilli (control) or containing a commercial probiotic culture (Lactobacillus rhamnosus LR32). L. plantarum presented viability higher than 7 log CFU g-1 in the dessert, as did the commercial probiotic, for 21 days at 4 ± 1 °C. Total phenolic contents (45⁻60 mg gallic acid equivalents, GAE, 100 g-1) were comparable to those of other studies evaluating dairy products containing plant sources. The formulations were low in fat, presenting as acceptable for overall consumption, with attractive color and appreciable texture. Considering the total antioxidant capacity, 200⁻250 g of dessert would be necessary to capture 1 g of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The dessert with Lactobacillus plantarum CNPC003 is seen as a viable alternative for the use of whey and jabuticaba peel, as well as a potential functional food due to the concentration of lactobacilli reached, besides the presence of antioxidant phenolic compounds.

Comparison of dairy desserts produced with a potentially probiotic mixed culture and dispersions obtained from Gracilaria birdiae and Gracilaria domingensis seaweeds used as thickening agents

Dairy desserts have emerged as interesting options for the incorporation of probiotics, bioactive ingredients and alternative sources of thickeners. This shows an opportunity to investigate the use of Gracilaria seaweeds in the formulation of potentially probiotic dairy desserts. This study aimed to compare the effects of dispersions obtained from Gracilaria domingensis and Gracilaria birdiae used as thickening agents on texture properties of dairy desserts fermented with SAB 440-A, composed of the starter Streptococcus thermophilus and the potential probiotics Bifidobacterium animalis and Lactobacillus acidophilus, and also to study their physicochemical characteristics, microbial viability and sensory acceptability. No significant differences between desserts with G. birdiae or G. domingensis dispersions regarding total solids, ash and fat content, as well as pH, titratable acidity, the viability of the microorganisms of the mixed culture and sensory acceptability were verified (P > 0.05). Nonetheless, the dessert with G. domingensis dispersion showed higher dietary fibre content and significantly increased firmness than the one produced with G. birdiae (P < 0.05). Moreover, B. animalis was able to maintain higher populations, above 7 log cfu g^-1 during 21 days of storage of desserts, in the presence of either G. birdiae or G. domingensis dispersions, despite the fact that L. acidophilus has shown low viability in the final products. Therefore, the G. domingensis dispersion is suitable to be used as a thickening agent to produce dairy desserts with enhanced firmness and good sensory acceptability, it being also advisable to use only B. animalis as a probiotic for this product.

Assessment of antioxidant activity, lipid profile, general biochemical and immune system responses of Wistar rats fed with dairy dessert containing Lactobacillus acidophilus La-5

The viability and survival of Lactobacillus acidophilus La5 under in vitro simulated gastrointestinal in probiotic dairy dessert was assessed. In addition, the effects of regular consumption of the dessert (5g/day) on the lipid profile, immune system, and antioxidant/biochemical status of Wistar rats were also evaluated after 2weeks of treatment. Adequate counts of L. acidophilus La-5 were observed regards the viability and gastrointestinal conditions. The probiotic dairy dessert was efficient in reducing the LDL-cholesterol, triacylglycerol and increased the HDL-cholesterol in serum. Aspartate amino transferase, alanine aminotransferase, total protein, albumin, heat shock proteins, immune system responses, and blood-cells counts (monocyte, lymphocyte, neutrophil and leucocyte) were not affected (p>0.05) after 15days of treatment. Overall, the probiotic dairy dessert may be a viable alternative to enhance the blood lipid profile and could be used to improve the antioxidant defenses.

Fermented food in the context of a healthy diet: how to produce novel functional foods?

PURPOSE OF REVIEW

This review presents an overview of recent studies on the production of functional fermented foods, of both traditional and innovative natures, and the mapping of the functional compounds involved.

RECENT FINDINGS

The functional aspects of fermented foods are mostly related to the concept of probiotic bacteria or the targeted microbial generation of functional molecules, such as bioactive peptides, during food fermentation. Apart from conventional yoghurt and fermented milks, several fermented nondairy foods are globally gaining in interest, in particular from soy or cereal origin, sometimes novel but often originating from ethnic (Asian) diets. In addition, a range of functional nonmicrobial compounds may be added to the fermented food matrix. Overall, a wide variety of potential health benefits is being claimed, yet often poorly supported by mechanistic insights and rarely demonstrated with clinical trials or even animal models.

SUMMARY

Although functional foods offer considerable market potential, several issues still need to be addressed. As most of the studies on functional fermented foods are of a rather descriptive and preliminary nature, there is a clear need for mechanistic studies and well controlled in-vivo experiments.