FERMENTATION OF WHOLE APPLE JUICE USINGLACTOBACILLUS ACIDOPHILUSFOR POTENTIAL DIETARY MANAGEMENT OF HYPERGLYCEMIA, HYPERTENSION, AND MODULATION OF BENEFICIAL BACTERIAL RESPONSES

Chemical Profile Characterization of Fruit and Vegetable Juices after Fermentation with Probiotic Strains

Lactic acid bacteria (LAB) are widely applied for fermentation purposes in dairy and non-dairy food matrices with beneficial technological and health-promoting properties. This study describes the effect of two lactic acid bacteria, namely, Lactiplantibacillus paracasei SP5 and Pediococcus pentosaceus SP2, on the phenolic profiles, antioxidant activities, total phenolic content (TPC), carotenoid content, and sensorial profile of two different mixed fruit juices. After 48 h of fermentation, both LABs retained viability over 9 Log CFU/mL in both juices. The TPC, zeaxanthin + lutein, β-carotene content, and antioxidant activity (AA) were elevated for both LABs and mixed juices after 48 h of fermentation compared to control samples. Regarding the phenolic profile, both juices exhibited a significant decrease in chlorogenic acid levels, while quinic acid and tyrosol concentrations showed notable increases.

Spontaneous fermentation improves the physicochemical characteristics, bioactive compounds, and antioxidant activity of acerola (Malpighia emarginata D.C.) and guava (Psidium guajava L.) fruit processing by-products

This study aimed to investigate the effects of spontaneous fermentation on physicochemical characteristics, bioactive compounds, and antioxidant activity of acerola and guava fruit industrial by-products. Viable cell counts of lactic acid bacterial (LAB) in acerola and guava by-products were ≥ 5.0 log CFU/mL from 24 h up to 120 h of fermentation. Fermented acerola and guava by-products had increased luminosity and decreased contrast. Contents of total soluble solids and pH decreased, and titrable acidity increased in acerola and guava by-products during fermentation. Ascorbic acid contents decreased in acerola by-product and increased in guava by-product during fermentation. Different phenolic compounds were found in acerola and guava by-products during fermentation. Fermented acerola and guava by-products had increased contents of total flavonoids, total phenolics, and antioxidant activity. The contents of total flavonoids and total phenolics positively correlated with antioxidant activity in fermented acerola and guava by-products. These results indicate that spontaneous fermentation could be a strategy to improve the contents of bioactive compounds and the antioxidant activity of acerola and guava by-products, adding value and functionalities to these agro-industrial residues.

High Hydrostatic Pressure Treatments Improved Properties of Fermentation of Apple Juice Accompanied by Higher Reserved Lactobacillus plantarum

This study aimed to assess the feasibility of high hydrostatic pressure (HHP) treatment to obtain high quality juice, and prepared functional apple juice using fermentation technology. The physicochemical properties of HHP (10 min) pasteurized and pasteurized (85 °C, 15 min) apple juices were compared during fermentation. Moreover, the survival of Lactobacillus plantarum after fermentation under simulated gastrointestinal conditions was evaluated. Results showed that HHP-treated apple juice had better properties than that of pasteurized in terms of color difference, total phenol content, and antioxidant activity. After fermentation, about 2.00 log CFU/mL increase in viability of cells was observed and there was around 0.8 reduction in pH value, and the antioxidant capacities were also significantly improved. Additionally, the content of caffeic acid, ferulic acid, and chlorogenic acid significantly increased after 24 h of fermentation. The survival of Lactobacillus plantarum in simulated gastric fluid reached 97.37% after fermentation. Overall, HHP treatment is expected to be a substitute technology to pasteurization in order to obtain higher quality fermented fruit juice. This study could also be helpful for exploitation of fermented juice.

Effects of Probiotic Fermented Fruit Juice-Based Biotransformation by Lactic Acid Bacteria and Saccharomyces boulardii CNCM I-745 on Anti-Salmonella and Antioxidative Properties

Fermentation is an effective process for providing various beneficial effects in functional beverages. Lactic acid bacteria and yeast fermentation-based biotransformation contribute to enhancement of nutritional value and digestibility, including lactose intolerance reduction and control of infections. In this study, the probiotic fermented fruit juice (PFJ) was produced by Lactobacillus plantarum TISTR 1465, Lactobacillus salivarius TISTR 1112, and Saccharomyces boulardii CNCM I-745 while mixed fruit juice (MFJ) was used as the basic medium for microorganism growth. The potential function, the anti-salmonella activity of PFJ, was found to be effective at 250 mg/ml of MIC and 500 mg/ml of MBC. Biofilm inhibition was performed using the PFJ samples and showed at least 70% reduction in cell attachment at the MIC concentration of Salmonella Typhi DMST 22842. The antioxidant activities of PFJ were determined and the results revealed that FSB.25 exhibited 78.40 ± 0.51 mM TE/ml by FRAP assay, while FPSB.25 exhibited 3.44 ± 0.10 mM TE/ml by DPPH assay. The volatile compounds of PFJ were characterized by GC-MS, which identified alcohol, aldehyde, acid, ester, ketone, phenol, and terpene. The most abundant organic acid and alcohol detected in PFJ were acetic acid and 2-phenylethanol, and the most represented terpene was β-damascenone. The sensory attributes showed scores higher than 7 on a 9-point hedonic scale for the FPB.25, illustrating that it was well accepted by panelists. Taken together, our results showed that PFJ could meet current consumer demand regarding natural and functional, fruit-based fermented beverages.

Fermentation of the Cucurbita ficifolia Fruit Juice: Its Antioxidant Activity and Effects on the Glycemia

Cucurbita ficifolia is an edible plant whose fruits have hypoglycemic, anti-inflammatory, and antioxidant activities. Fermentation might improve these properties. This research aims to perform and characterize its fermentation in native and induced conditions with Lactobacillus plantarum (Lp) and evaluate its antioxidant activity and effect on glycemia. Fresh juice from mature fruits was characterized. One portion of this juice was spontaneously left to ferment (native fermentation), and the other was inoculated with Lp (controlled fermentation). Fermentation was monitored each 8 h by 56 h to measure microbial growth, pH, acidity, sugars, soluble protein, polyphenols and flavonoids, antioxidant activity, and effects on glycemia. In native fermentation, the growth of total microorganisms increased up to 32 h, decreasing at the end of the process. In Lp fermentation, total microorganisms increased until 16 h to stay constant at the end, with a predominance of Lp. The pH and the sugars decreased in the two fermentations, while polyphenol and flavonoid increased. In spontaneous fermentation, these changes were lesser. Both fermentations, like fresh juice, preserve functional properties (antioxidant, alpha-glucosidase inhibition, and hypoglycemia). The fermentation of this juice with Lp may develop functional beverages, which is significant due to its consumption as an edible fruit with medicinal properties.

Fermentation and Storage Characteristics of “Fuji” Apple Juice Using Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum: Microbial Growth, Metabolism of Bioactives and in vitro Bioactivities

Fruit juices have been widely used as the substrates for probiotic delivery in non-dairy products. In this study, three lactic acid bacteria (LAB) strains, including Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum, were selected to ferment apple juice. During 72-h of fermentation, these LAB strains grew well in the apple juice with significant increases in viable cell counts (from 7.5 log CFU/mL to 8.3 log CFU/mL) and lactic acid content (from 0 to 4.2 g/L), and a reduction of pH value (from 5.5 to around 3.8). In addition, the antioxidant and antibacterial capacities of fermented apple juice in vitro were significantly improved through the phenolic and organic acid metabolisms. After storage at 4°C for 30 days, the total amino acid content of fermented apple juice was significantly increased, although the viable cell counts and total phenolic content were decreased (p < 0.05). Furthermore, the stored fermented apple juices still possessed antibacterial and in vitro antioxidant activities. Overall, all the selected LAB strains could be suitable for apple juice fermentation and can effectively improve their biological activities.

Improving Health Targeted Food Quality of Blackberry: Pear Fruit Synergy Using Lactic Acid Bacterial Fermentation

Blackberry and pear are rich in human health protective phenolic bioactives with high antioxidant activity. These fruits are relevant dietary targets to counter chronic oxidative stress-linked diseases, such as type 2 diabetes (T2D). Due to high perishability, the human health relevant bioactive qualities of such fruits deteriorate during postharvest storage and processing. By improving stability and bioavailability of nutritionally relevant phenolic bioactives during post-harvest stages, effective integration of blackberry and pear as dietary support strategies can be targeted for T2D benefits. Solutions to bioactive quality loss of fruits can be achieved by advancing bioprocessing strategy integrating compatible fruit synergy and beneficial lactic acid bacteria (LAB) based fermentation. This approach was targeted to enhance high levels of phenolic bioactive-linked health quality of blackberry (Rubus spp.) integrated with pear (Pyrus communis) at a ratio of 30:70, which was optimized previously based on potential synergistic effects. The aim of this study was to recruit beneficial LAB such as Lactobacillus helveticus and Bifidobacterium longum to bioprocess previously optimized blackberry: pear synergies to improve phenolic bioactive-linked T2D benefits. Essential health-targeted food quality during bioprocessing was assessed based on total soluble phenolic content, phenolic compound profile, total antioxidant activity, anti-hyperglycemic property relevant α-amylase and α-glucosidase enzyme inhibitory, and anti-hypertensive relevant angiotensin-I-converting enzyme (ACE) inhibitory activities using in vitro assay models. Additionally, potential inhibitory activity of fermented fruit extracts against pathogenic Helicobacter pylori, the common bacterial ulcer pathogen was also investigated. Overall, improvement in the retention and stability of phenolic bioactive content in 30:70 blackberry: pear combination, as well as in 100% juice of both fruit extracts were observed following fermentation. Furthermore, enhanced antioxidant activity, anti-hyperglycemic property relevant α-glucosidase, and anti-hypertensive property relevant ACE enzyme inhibitory activities were also observed in fermented extracts of 30:70 blackberry: pear synergy. Among the substrates only fermentation of 100% blackberry with LAB resulted in inhibitory activity against H. pylori. These results provide the biochemical rationale to develop blackberry: pear fruit synergy and beneficial LAB-based fermentation to improve T2D relevant health benefits while also potentially improving keeping quality.

Application of ultrasonication at different microbial growth stages during apple juice fermentation by Lactobacillus plantarum: Investigation on the metabolic response

In this work, low-intensity ultrasonication (58.3 and 93.6 W/L) was performed at lag, logarithmic and stationary growth phases of Lactobacillus plantarum in apple juice fermentation, separately. Microbial responses to sonication, including microbial growth, profiles of organic acids profile, amino acids, phenolics, and antioxidant capacity, were examined. The results revealed that obvious responses were made by Lactobacillus plantarum to ultrasonication at lag and logarithmic phases, whereas sonication at stationary phase had a negligible impact. Sonication at lag and logarithmic phases promoted microbial growth and intensified biotransformation of malic acid to lactic acid. For example, after sonication at lag phase for 0.5 h, microbial count and lactic acid content in the ultrasound-treated samples at 58.3 W/L reached 7.91 ± 0.01 Log CFU/mL and 133.70 ± 7.39 mg/L, which were significantly higher than that in the non-sonicated samples. However, the ultrasonic effect on microbial growth and metabolism of organic acids attenuated with fermentation. Moreover, ultrasonication at lag and logarithmic phases had complex influences on the metabolism of apple phenolics such as chlorogenic acid, caffeic acid, procyanidin B2, catechin and gallic acid. Ultrasound could positively affect the hydrolysis of chlorogenic acid to caffeic acid, the transformation of procyanidin B2 and decarboxylation of gallic acid. The metabolism of organic acids and free amino acids in the sonicated samples was statistically correlated with phenolic metabolism, implying that ultrasound may benefit phenolic derivation by improving the microbial metabolism of organic acids and amino acids.

Phenolic Bioactives From Plant-Based Foods for Glycemic Control

Plant-based foods containing phenolic bioactives have human health protective functions relevant for combating diet and lifestyle-influenced chronic diseases, including type 2 diabetes (T2D). The molecular structural features of dietary phenolic bioactives allow antioxidant functions relevant for countering chronic oxidative stress-induced metabolic breakdown commonly associated with T2D. In addition to antioxidant properties, phenolic bioactives of diverse plant foods have therapeutic functional activities such as improving insulin sensitivity, reducing hepatic glucose output, inhibiting activity of key carbohydrate digestive enzymes, and modulating absorption of glucose in the bloodstream, thereby subsequently improving post-prandial glycemic control. These therapeutic functional properties have direct implications and benefits in the dietary management of T2D. Therefore, plant-based foods that are rich in phenolic bioactives are excellent dietary sources of therapeutic targets to improve overall glycemic control by managing chronic hyperglycemia and chronic oxidative stress, which are major contributing factors to T2D pathogenesis. However, in studies with diverse array of plant-based foods, concentration and composition of phenolic bioactives and their glycemic control relevant bioactivity can vary widely between different plant species, plant parts, and among different varieties/genotypes due to the different environmental and growing conditions, post-harvest storage, and food processing steps. This has allowed advances in innovative strategies to screen and optimize whole and processed plant derived foods and their ingredients based on their phenolic bioactive linked antioxidant and anti-hyperglycemic properties for their effective integration into T2D focused dietary solutions. In this review, different pre-harvest and post-harvest strategies and factors that influence phenolic bioactive-linked antioxidant and anti-hyperglycemic properties in diverse plant derived foods and derivation of extracts with therapeutic potential are highlighted and discussed. Additionally, novel bioprocessing strategies to enhance bioavailability and bioactivity of phenolics in plant-derived foods targeting optimum glycemic control and associated T2D therapeutic benefits are also advanced.

Isolation, characterisation and exploitation of lactic acid bacteria capable of efficient conversion of sugars to mannitol

The demand for sugar reduction in products across the food and beverage industries has evoked the development of novel processes including the application of fermentation with lactic acid bacteria. Heterofermentative lactic acid bacteria (LAB) are diverse in their ability to utilise fermentable sugars and can also convert fructose into the sweet tasting polyol, mannitol. The sourdough microbiota has long been recognised as an ecological niche for a range of homofermentative and heterofermentative lactic acid bacteria. A leading determinant in the biodiversity of sourdough microbial populations is the type of flour used. Ten non-wheat flours were used and back-slopped for 7 days resulting in the isolation of 52 mannitol producing isolates which spanned six heterofermentative species of the genera Lactobacillus, Leuconostoc and Weissella. Assessment of mannitol productivity in fructose concentrations up to 100 g/L found Leuconostoc citreum TR116, to have the best mannitol producing characteristics, consuming 95% of available fructose and yielding 0.68 g of mannitol per gram of fructose consumed which equates to the maximal theoretical yield. Investigation of the effects of initial pH on mannitol production and other fermentation parameters in the isolates found pH 7 to be best for isolates Lactobacillus brevis TR052, Leuconostoc fallax TR111, Leuconostoc citreum TR116, Leuconostoc mesenteroides TR154 and Weissella paramesenteroides TR212, while pH 6 was optimal for Leuconostoc pseudomesenteroides TR080. The fermentation of apple juice with each isolate resulted in sugar reduction ranging from 30.3-74.0 g/L (34-72%). When apple juice fermentation with Leuconostoc citreum TR116 was scaled up to 1 L bioreactor a reduction in sugar of 98.6 g/L (83%) was achieved along with the production of 61.6 g/L mannitol. This demonstrates a fermentative process for sugar reduction in fruit juice with concomitant production of the sweet metabolite mannitol to create a fermentate that is suitable for further development as a low sugar fruit juice alternative.

Effects of Agitation Speed and Kinetic Studies on Probiotication of Pomegranate Juice with Lactobacillus casei

The issues of lactose intolerance and vegetarianism have encouraged the introduction of non-dairy fermented food into the market. Therefore, this study aims to evaluate the effect of agitation speed on the bioactive compounds and functional characteristics of probioticated pomegranate juice. Pomegranate juice was fermented with Lactobacillus casei at different agitation speeds ranging from 0 (microaerophilic) to 150 rpm at 37 °C. The functional properties of probioticated pomegranate juice were evaluated in terms of growth (biomass), lactic acid production, antioxidant activity, total phenolic content, and key metabolites using LC-MS/MS. The growth kinetics of fermentation was monitored at the optimal condition using one factor at a time method. High cell growth (3.58 × 1010 cfu/mL or 7.9 gL-1) was observed for L. casei probioticated pomegranate juice agitated at 0 rpm. The findings of this study reveal the potential of pomegranate juice as a medium for L. casei cultivation without nutrient supplementation. The improvement of antioxidant activity in the probioticated juice could be due to the increment of quercetin-3-glucoside. Therefore, L. casei grew well in pomegranate juice with a high cell viability and antioxidant activity at a non-agitated condition. Probioticated pomegranate juice is a potentially functional drink.

Changes in physico-chemical, astringency, volatile compounds and antioxidant activity of fresh and concentrated cashew apple juice fermented with Lactobacillus plantarum

Changes in physico-chemical qualities (pH, total acidity, total and reducing sugar, total phenolic and vitamin C), astringency compounds (condensed and hydrolysable tannin), antioxidant activities [2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical] and flavor volatile compounds in Lactobacillus plantarum-fermented cashew-apple-juice (CAJ) and 11.4 °Bx concentrated-cashew-apple-juice (CCAJ) was investigated. Total phenolics remained unchanged throughout fermentation period, whereas condensed tannins increased and hydrolysable tannins decreased indicating reduced astringency compounds. Antioxidant activity based on both DPPH and ABTS radical scavenging activities marginally declined in some stages but overall were sustained during fermentation. Although the DPPH· radical based antioxidant activity of fermented CAJ was greater than that of fermented 11.4 °Bx CCAJ, a higher ABTS·+ radical scavenging activity was found in fermented 11.4 °Bx CCAJ, reflecting higher water soluble antioxidants. Results also indicated that DPPH· radical scavenging activity was positively correlated to vitamin-C and condensed tannins but not hydrolysable tannins. ABTS·+ radical scavenging activity was also positively correlated to condensed tannins and not hydrolysable tannins. The vitamin-C that increased during initial 12 h fermentation, decreased from 2516 to 2150 mg AAE/L at the end of 72 h fermentation. Fermented CAJ had a remarkable sweet aroma with a fruity note of two major compounds; 3-methyl-1-butanol (14.20 × 107) and 2,6-dimethyl-4-heptanol (14.76 × 107). The high phytochemicals and volatile compounds in fermented CAJ indicated that it could serve as a functional beverage with potential health benefits with reduced astringency due to lower hydrolysable tannins.

Improved release and metabolism of flavonoids by steered fermentation processes: a review

This paper provides an overview on steered fermentation processes to release phenolic compounds from plant-based matrices, as well as on their potential application to convert phenolic compounds into unique metabolites. The ability of fermentation to improve the yield and to change the profile of phenolic compounds is mainly due to the release of bound phenolic compounds, as a consequence of the degradation of the cell wall structure by microbial enzymes produced during fermentation. Moreover, the microbial metabolism of phenolic compounds results in a large array of new metabolites through different bioconversion pathways such as glycosylation, deglycosylation, ring cleavage, methylation, glucuronidation and sulfate conjugation, depending on the microbial strains and substrates used. A whole range of metabolites is produced, however metabolic pathways related to the formation and bioactivities, and often quantification of the metabolites are highly underinvestigated. This strategy could have potential to produce extracts with a high-added value from plant-based matrices.