Development of processes for the production of postbiotic functional foods

Several techniques were developed in order to enhance the content of bioactive compounds or promote their production in food products. Lactic acid fermentation is one of the most important food processing technologies used to produce functional probiotic foods. A novel category of fermented functional foods is gaining increasing interest and is represented by postbiotic products, consisting of inactivated microorganisms and molecules (enzymes, peptides, organic acids) produced in the final or intermediate stage of the metabolic process of these probiotic bacteria. Although postbiotics do not contain live microorganisms, they show a beneficial health effect through similar mechanisms that are characteristic of probiotics, minimizing the risks associated with their intake. For this reason, they could be considered a safer alternative to clinical application for immune-deficient patients or infants. This research, in collaboration with Kraft Heinz Company, consisted of the development of processes for the production of wet and dried functional foods with a postbiotic effect, intended for categories of people with high pathological vulnerability, such as children, elderly people and pregnant women. The purpose of this project was to investigate the effect of fermentation process, carried out using Lactobacillus paracasei CBA L74, patented by Kraft Heinz, heat treatments and drying processes on the postbiotic properties of the semi-finished products obtained, choosing as raw materials milk, rice flour and leguminous (beans) suspensions. The processes were examined and optimized at laboratory scale and then implemented at pilot scale with a successful and efficient scaling up, except for beans that had been an unexplored food matrix to be fermented until then and required a further optimization of protocols at laboratory scale before performing the trials on the pilot plant. At lab scale, rice and milk fermentation were carried out with and without pH control and in both cases an improvement in the terms of kinetic performance of the process was observed when pH control was implemented. The fermentation process was characterized in terms of bacterial growth (maximum values of 1.9 × 10^8 ± 1.2 × 10^8 CFU/mL after 20 h and 5.3 × 10^8 ± 4.7 × 10^8 CFU/mL after 18 h were achieved for milk and rice flour fermentations, respectively), lactic acid concentration (maximum values of 1.2 ± 0.3 g/L and 4.4 ± 0.21 g/L were achieved after 24 h of fermentation process for milk and rice flour, respectively) and production of a selected functional metabolite, considered as responsible of the immunomodulatory activity of the postbiotics obtained (6.93 ± 0.5 mg/L and 17.23 ± 0.28 mg/L after 24 h of fermentation, for milk and rice flour,respectively). An aqueous suspension of cooked beans was fermented without pH control in two different mixing conditions. The mixing system was improved by designing an impeller that guarantees a higher homogeneity of the medium inside the reactor: the results showed better performances in terms of growth rate and lactic acid production, reaching a microbial charge of approximately 1 × 10^9 CFU/mL after 14 h and a lactic acid content of 2 g/L after 16 h of process. The functional peptide was not detected in the fermenting bean suspension, so a further optimization of the protocol will be necessary for this purpose. A thermal treatment at 90°C for 1 min, for rice and milk, and at 90°C for 15 min, for beans, was sufficient to reduce the bacterial charge in the fermented product without negatively affecting the products quality; freeze drying and spray drying technologies had the same impact on the food products, not altering their organoleptic and chemical properties: a promising result since spray drying technology is usually used at larger scale. The results obtained at pilot scale for milk and rice flour were completely overlapped. During milk fermentation, a maximum bacterial load of 6.7 × 10^8 ± 2.65 × 10^8 CFU/mL was reached after 20 h of process; a lactic acid content of 2.1 ± 0.25 g/L and a peptide concentration of 14.20 ± 0.80 mg/L were observed at the end of fermentation. As for rice flour, a maximum bacterial growth of 1.27 × 10^9 ± 6.9 × 10^8 after 18 h of process, a maximum lactic acid production of 6.03 ± 0.7 g/L after 24 h and a maximum functional peptide content of 22.60 ± 4.10 mg/L after 20 h of fermentation were obtained. For both scales, rice flour fermentation gave better results in terms of bacterial growth, lactic acid and functional peptide production, probably for the rice prebiotic components. Also, at pilot scale, a thermal treatment of 90°C for 1 min was sufficient to reduce the bacterial charge in the fermented products and it was confirmed that spray drying technology had a low impact on the product. Moreover, a shelf-life analysis of the products obtained at pilot scale was performed at three different storage temperatures (4°C, 20°C and 37°C) for six months to evaluate the food product stability over time: dried fermented rice resulted more stable than milk

Effects of the Glucose Addition during Lactic Fermentation of Rice, Oat and Wheat Flours

 Background and objective: Consumer interests in probiotic foods have increased in recent decades. Food industries respond to these growing interests by developing innovative products and guaranteeing high production efficiency. Cereals, due to their prebiotic nature, are good fermentable substrates; from which, potentially functional foods could be achieved. The aim of this study was to verify effects of D-glucose addition on fermentation of rice, oat and wheat flours.Material and methods: Suspensions of 15% of cereals flours (rice, oat and wheat) in distilled water added with increasing glucose concentrations (2, 5, 7 and 10% w v-1) were fermented by Lactobacillus paracasei CBA L74 for 24 h. Then, pH, microbial growth and lactic acid production were assessed.Results and conclusion: Rice fermentation was not affected by glucose addition. For oat and wheat, addition of D-glucose increased bacterial concentration, as well as lactic acid production. In particular, the best growth was achieved by the addition of 2 and 5% of glucose. Furthermore, lactic acid concentration increased with increased glucose concentration. In conclusion, D-glucose addition seems to be unnecessary for the improvement of rice fermentation. On the contrary, oat and wheat fermentations need further available carbon sources for a better Lactobacillus growth and a higher lactic acid production.Conflict of interest: The authors declare no conflict of interest

Using Hydrofluorocarbon Extracts of Hop in a Pilot Scale Brewing Process

In recent years, the use of hop extracts in industrial and home brewing processes as an alternative to hop cones or pellets usually added to wort during boiling has become increasingly popular. These extracts represent concentrated sources of bitter compounds, i.e., α- and β-acids, which are involved in some of the main reactions that take place in the wort and are responsible for the bitterness and the final quality of beer. This work aims at proposing a novel extraction technique, using a hydrofluorocarbon solvent in subcritical conditions; this process provided an extraction yield of 19% and an α-acid recovery of approximately 49% in 120 min of process. The α-acid isomerization kinetics of thermally treated hop extracts were studied and compared with those of both hop pellets and a CO2 extract. Laboratory scale tests showed that shorter boiling times were needed using hydrofluorocarbon and CO2 extracts (approximately 25 min and 34 min, respectively) to reach the same isomerization efficiency of 16.73%, achieved in 50 min of boiling with pellets. Moreover, the process was scaled up and the possibility of considerably reducing the conventional treatment times using hydrofluorocarbon extracts was confirmed: the same isomerization yield (9.1%) obtained after 50 min using the traditional procedure with hop pellets was reached in a shorter time of approximately 35 min in a pilot apparatu

Recovery of Carotenoids from Tomato Pomace Using a Hydrofluorocarbon Solvent in Sub-Critical Conditions

The enrichment of oils with nutraceutical bioactive phytomolecules allows the achievement of functional oil-based products of great interest in the food, pharmaceutical, and cosmetic fields. Carotenoids, such as lycopene and β-carotene, are available at a high concentration in tomatoes and tomato waste products, as peels, seeds, and pulp; their recovery is recently attracting growing interest and economic importance in the food industry, and also in consideration of the huge amount of industrial waste produced. The aim of this work is to study the production of an oil functionalized with carotenoids from tomato peels. The extractions were carried out using an innovative process based on the use of commercial Norflurane as solvent in subcritical conditions. Extraction trials were performed on dried tomato peels, with the addition of tomato seeds or wheat germ flour as sources of oily co-solvents, capable of also preserving the biological characteristics of the carotenoids extracted. Although lycopene solubility in Norflurane is quite low, the solvent recirculation and regeneration were allowed to reach a concentration in the oily extracts of approximately 0.3 mg/goil after 2 h of the process. The enrichment in β-carotene was more pronounced, and concentrations of 0.733 mg/goil and 0.952 mg/goil were observed in wheat germ and tomato seed oils, respectively. The results obtained in this study were compared with those obtained by traditional and supercritical CO2 extraction methods

Recovery of Carotenoids from Tomato Pomace Using a Hydrofluorocarbon Solvent in Sub-Critical Conditions

The enrichment of oils with nutraceutical bioactive phytomolecules allows the achievement of functional oil-based products of great interest in the food, pharmaceutical, and cosmetic fields. Carotenoids, such as lycopene and β-carotene, are available at a high concentration in tomatoes and tomato waste products, as peels, seeds, and pulp; their recovery is recently attracting growing interest and economic importance in the food industry, and also in consideration of the huge amount of industrial waste produced. The aim of this work is to study the production of an oil functionalized with carotenoids from tomato peels. The extractions were carried out using an innovative process based on the use of commercial Norflurane as solvent in subcritical conditions. Extraction trials were performed on dried tomato peels, with the addition of tomato seeds or wheat germ flour as sources of oily co-solvents, capable of also preserving the biological characteristics of the carotenoids extracted. Although lycopene solubility in Norflurane is quite low, the solvent recirculation and regeneration were allowed to reach a concentration in the oily extracts of approximately 0.3 mg/goil after 2 h of the process. The enrichment in β-carotene was more pronounced, and concentrations of 0.733 mg/goil and 0.952 mg/goil were observed in wheat germ and tomato seed oils, respectively. The results obtained in this study were compared with those obtained by traditional and supercritical CO2 extraction methods

Optimization of Mixing Conditions for Improving Lactobacillus Paracasei Cba L74 S Growth During Lactic Fermentation of Cooked Navy Beans and Functional Characterization of the Fermented Products

Lactic acid fermentation of legume-based matrices has been gaining an increasing interest in recent years to produce pro- and post-biotic functional foods at high protein content. The optimization of the main process conditions is necessary to improve bacterial growth, microbial metabolic activity, thus the consequent functional properties of the resulting fermented products. A preliminary study of feasibility about the potential of using a leguminous substrate as growth medium for Lactobacillus paracasei CBA L74 was already conducted in previous experimentations. In this work, the effect of improving mixing conditions of a cooked navy bean suspension during the lactic acid fermentation process was investigated and some chemical and physical properties of the resulting fermented products were studied to verify their potential application as functional ingredients in food formulations. The mixing system was optimized by designing an impeller that guarantees a more homogeneous distribution of nutrients and avoids concentration gradients that could inhibit the microorganism proliferation. Bacterial growth, lactic acid production, sugar, and starch consumption were compared with those obtained during previous experimentations carried out with a different impeller. The major availability of nutrients in the fermenting medium reached with the customized impeller allowed a faster achievement of the maximum microbial load (1×109 CFU/mL after 14 h of process) and a lower doubling time of 1.53 h. Furthermore, fermentation led to a reduction in water absorption, oil binding, and foam capacity of the fermented bean powders. Total phenolic and flavonoid content and their antioxidant capacity were not influenced by the fermentation process itself but favored by the previous thermal treatment of sterilization

Functional Properties of an Oat-Based Postbiotic Aimed at a Potential Cosmetic Formulation

The concept of postbiotic has been attracting the attention of the scientific community and several industrial realities to develop new claims and new market segments for functional fermented products. The aim of this work was to develop a process to produce an oat-based postbiotic ingredient to be used in personal care cosmetic formulations. A hydrolyzed oatmeal suspension was fermented using Lacticaseibacillus paracasei CBA L74 as starter culture, at 37 °C for 48 h by controlling the pH; then the bacterial charge was inactivated by a mild thermal treatment at 80 °C for 30 s, obtaining a postbiotic. The effect of different process steps, hydrolysis, sterilization, fermentation, and inactivation phases, on lactic acid concentration, total polyphenolic content, antioxidant activity, tyrosinase inhibition activity and Sun Protection Factor value was investigated, demonstrating the potential cosmetic applications. The maximum bacterial growth and lactic acid production were achieved after 24 h of process, with a cell density and a lactic acid concentration of 3.05 × 109 CFU/mL and 8.60 g/L, respectively. The total phenolic content and the antioxidant activity reached their maximum values (2.5 mgGAE/mL, EC50 = 2.2 mg/mL and 1.38 × 10−2 mmol Fe2+/g and 7.3 × 10−3 mmol TE/g, respectively) after the sterilization treatment; the maximum tyrosinase inhibition of 50.6%, corresponding to a sample concentration of 16 mg/mL, was found after 24 h of fermentation process. Fermentation did not show an impact on UV shielding ability and the SPF value decreased during the process

Banana Puree Lactic Fermentation: The Role of Ripeness, Heat Treatment, and Ascorbic Acid

Banana puree, due to its nutritional composition, is a good substrate for fermentation in the development of probiotic products. The production of banana puree mainly consists of three phases, i.e., raw material pretreatment, heat treatment, and the addition of anti-browning agents. In this study, we conducted three experimental protocols to evaluate the effect of ripeness grade, heat treatment, and ascorbic acid addition on fermentation performance. At the end of each protocol, the substrate was subjected to the fermentation process (37 °C, 48 h), and then measurements of pH reduction, microbial growth, and lactic acid production were used as markers in the analysis of fermentation performance. Ripe bananas produced better results than unripe bananas whose fermentation appeared to be inhibited. Therefore, ripe bananas were used to test the effect of two different heat treatments (sterilization (121 °C, 20 min) versus tyndallization (70 °C, 30 min; 37 °C, 30 min; 70 °C, 30 min)) on banana puree fermentation, and no significant differences were observed. Finally, 500 or 1000 ppm of ascorbic acid, normally used as an anti-browning agent, was added to ripe tyndallized bananas. No differences in fermentation results were observed between the two tested conditions, though values obtained for growth and lactic acid production were significantly lower than those from fermentation of banana puree without ascorbic acid

Valorisation through Lactic Fermentation of Industrial Wastewaters from a Bean Blanching Treatment

In recent years, scientific research and industries have been focusing on the application of biological treatments aimed at imparting functional properties to waste products from food industries according to the principles on which the circular economy model is based, namely, the recovery, valorisation, and reuse of wastes. This work aimed at exploring the possibility of valorising waters from the blanching process of dried navy beans through lactic acid fermentation using Lacticaseibacillus paracasei CBA L74 as a starter. Two samples at different solid concentrations (0.75 °Bx and 1.25 °Bx) were fermented, and, in both cases, a bacterial load of 8 Logs and a lactic acid concentration of approximately 1.3 g/L were reached, despite the lack of nutrients. An unusual pH trend, characterised by an initial decrease and unexpected final rise, was observed during the fermentation of both samples: simultaneously, an increase in protein content was observed, suggesting that the proteolytic action of the microorganism could be responsible for the release of pH-increasing substances. In both cases, a slight increase in total polyphenols (approximately 23.3–33.72%) and flavonoids (approximately 42.3–52%) due to fermentation was observed, with a corresponding improvement in antioxidant capacity (approximately 25.32–37.72%). A significant increase in saponin concentration was determined for the most concentrated blanching water (from 2.87 ± 0.28 to 6.68 ± 0.69 mgOAE/mL), leading to an improvement in foaming properties and an enhanced capacity to produce stable emulsions. The obtained results confirmed the possibility of reducing water consumption from blanching operations, as well as finding valorisation opportunities for this side stream through a safe and inexpensive fermentation treatment

Role of Nutraceuticals in Counteracting Inflammation in In Vitro Macrophages Obtained from Childhood Cancer Survivors

The advancement of anti-cancer therapies has markedly improved the survival rate of children with cancer, making them long-term childhood cancer survivors (CCS). Nevertheless, these treatments cause a low-grade inflammatory state, determining inflamm-aging and, thus, favoring the early onset of chronic diseases normally associated with old age. Identification of novel and safer therapeutic strategies is needed to counteract and prevent inflamm-aging. Macrophages are cells involved in immune and inflammatory responses, with a pivotal role in iron metabolism, which is related to inflammation. We obtained macrophages from CCS patients and evaluated their phenotype markers, inflammatory states, and iron metabolism by Western blotting, ELISA, and iron assays. We observed a strong increase in classically activated phenotype markers (M1) and iron metabolism alteration in CCS, with an increase in intracellular iron concentration and inflammatory markers. These results suggest that the prevalence of M1 macrophages and alteration of iron metabolism could be involved in the worsening of inflammation in CCS. Therefore, we propose macrophages and iron metabolism as novel therapeutic targets to counteract inflamm-aging. To avoid toxic regimens, we tested some nutraceuticals (resveratrol, curcumin, and oil-enriched lycopene), which are already known to exert anti-inflammatory properties. After their administration, we observed a macrophage switch towards the anti-inflammatory phenotype M2, as well as reductions in pro-inflammatory cytokines and the intracellular iron concentration. Therefore, we suggest—for the first time—that nutraceuticals reduce inflammation in CCS macrophages through a novel anti-inflammatory mechanism of action, modulating iron metabolism