Strawberry Juice Research Articles

Valorization of Strawberry Juice Production Wastewater: Possibilities for Polyphenols Recovery and Plant Biostimulant Production.

Fruit juice production is one of the most important branches of the food and beverage industry, considering both the market size and demand. It is also one of the largest generators of industrial wastewater, considering the large consumption of fresh water during fruit processing. Hence, the appropriate treatment strategies are of the utmost importance to minimize the environmental footprint of food industry effluents. This study aimed to investigate the valorization routes for strawberry juice production wastewater (SJPW), both in terms of nutrient recovery and a circular approach to its utilization as a medium for plant biostimulant production. The results show a low antioxidant capacity and low content of polyphenols in SJPW; however, promising results were obtained for the in vitro seed germination and tomato growth promotion when investigating a biostimulant based on Bacillus sp. BioSol021, which was cultivated using SJPW in a lab-scale bioreactor, with root and shoot length improvements of approximately 30% and 25%, respectively, compared to the control samples. The plant growth promotion (PGP) traits indicated the ability of IAA production, in a concentration of 8.55 ± 0.05 mg/L, and the enzymatic activity was evaluated as through the enzymatic activity index (EAI), achieving the following: 2.26 ± 0.04 for cellulolytic activity, 2.49 ± 0.08 for hemicellulolytic activity, 2.91 ± 0.16 for pectinolytic activity, and 1.05 ± 0.00 for proteolytic activity. This study opens a new chapter of possibilities for the development of techno-economically viable circular bioprocess solutions aimed at obtaining value-added microbial products for sustainable agriculture based on the valorization of food industry effluents thus contributing to more sustainable food production at both the agricultural and industrial levels.

Sensory approach to added sugar reduction in strawberry juices using fuyu persimmon

The aim of this study was to produce strawberry juice with reduced added sugar content, use the alternative natural sweetness of persimmon, and evaluate its physicochemical and sensory characteristics. Five different strawberry juice formulations were prepared with a 25% reduction in the added sucrose content with 0, 12.5, 25, 37.5, and 50% added persimmon pulp. Color, soluble solids, pH, and titratable acidity were evaluated, and CATA and acceptance sensory tests were performed with 100 consumers. In general, adding persimmon pulp to strawberry juice significantly affects both its physicochemical and sensory properties. From a physicochemical point of view, as the persimmon content increased, the strawberry juice tended to turn from red to orange, and there was an increase in soluble solids content and pH, as well as a decrease in acidity. From a sensory point of view, changes in sensory profile and product acceptability were also observed. However, persimmon showed potential as a natural sweetener in strawberry juice to reduce added sugar. Formulations with lower levels of persimmon pulp (12.5 and 25%) showed promise as these formulations maintained the valued sensory characteristics of strawberry juice and used the natural sweetness of persimmon to reduce added sugars, making them healthier beverage alternatives.

Unraveling the color evolution and metabolic pathways of pelargonidin-3-O-glucoside during lactic acid fermentation of the strawberry juice color simulation system: A novel perspective through untargeted metabolomics

This study aimed to unraveling the color evolution and metabolic pathways of pelargonidin-3-O-glucoside (P3G) during lactic acid fermentation of the strawberry juice color simulation system. The results revealed that fermentation with both Lactobacillus plantarum and Lactobacillus acidophilus caused a decline in pH of the strawberry juice color simulation system and significantly accelerated the decrease in P3G content. The CIELAB space model pointed out that parameters a⁎ and b⁎ of the group treated with both lactic acid bacteria and P3G initially increased to a peak level and then gradually decreased, shifting the overall color towards orange and then gradually fading. Furthermore, untargeted metabolomics results revealed that P3G was progressively degraded and converted to pyruvate, methylparaben, 3,4-dihydroxybenzoic acid, p-anisic acid, and terephthalic acid, affecting the metabolic pathways of glycolysis, d-amino acids, benzoate degradation, aromatic compounds degradation, and aminobenzoate degradation in lactic acid bacteria.

Effects of Cultivar Factors on Fermentation Characteristics and Volatile Organic Components of Strawberry Wine.

Strawberry wine production is a considerable approach to solve the problem of the Chinese concentrated harvesting period and the short shelf life of strawberries, but the appropriative strawberry cultivars for fermentation are still undecided. In this study, the strawberry juice and wines of four typical strawberry cultivars named Akihime (ZJ), Sweet Charlie (TCL), Snow White (BX), and Tongzhougongzhu (TZ) were thoroughly characterized for their physicochemical indicators, bioactive compounds, and volatile organic components (VOCs) to determine the optimal strawberry cultivars for winemaking. The results showed that there were significant differences in the total sugar content, pH, total acid, and other physicochemical indexes in the strawberry juice of different cultivars, which further affected the physicochemical indexes of fermented strawberry wine. Moreover, the content of polyphenols, total flavonoids, vitamin C, and color varied among the four strawberry cultivars. A total of 42 VOCs were detected in the strawberry juice and wines using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and 3-methyl-1-butanol, linalool, trans-2-pinanol, hexanoic acid, and hexanoic acid ethyl ester were the differential VOCs to identify the strawberry wine samples of different cultivars. Overall, strawberry cultivar ZJ had a relatively high VOC and bioactive compound content, indicating that it is the most suitable cultivar for strawberry wine fermentation. In addition to determining the relatively superior fermentation characteristics of cultivar ZJ, the results may provide a theoretical basis for the raw material quality control and quality improvement of strawberry wine.

Influence of physicochemical characteristics on the growth and guaiacol production of Alicyclobacillus acidoterrestris in fruit juices

Alicyclobacillus acidoterrestris is a bacterium known for causing spoilage in the taste and odour of fruit juices due to its thermoacidophilic nature. Its spoilage is attributed to the formation of guaiacol, which requires the presence of suitable precursors in the juices that A. acidoterrestris can metabolize. Therefore, A. acidoterrestris could exhibit different behaviour depending on the physicochemical characteristics the juice. In this study, we aimed to evaluate the behaviour of five A. acidoterrestris strains in seven different fruit juices by monitoring total cell and spore populations and quantifying guaiacol production. Also, physicochemical and phenolic profile, focusing on antimicrobials and guaiacol precursors, were analysed to better understand differences. Results showed growth in orange, apple, and plum juices for all the tested strains, with total cell populations reaching approximately 7 log cfu/mL, except for plum juice. In persimmon juice, growth was only observed in 3 out of 5 strains, for both total cells and spores. In contrast, all strains were inhibited in peach, black grape, and strawberry juices, maintaining a consistent population around 4 log cfu/mL. A strong negative correlation was observed between bacterial population and compounds such as kaempferol (for strains R3, R111, and P1), cyanidin chloride (for strains R111 and P1), and p-coumaric acid (for strain 7094 T). Regarding guaiacol production, orange and persimmon juices exhibited the highest guaiacol levels, with strain P1 (362.3 ± 12.6 ng/mL) and strain EC1 (325.1 ± 1.4 ng/mL) as the top producers, respectively. Plum, black grape, and strawberry juices showed similar guaiacol concentrations (16.9 ± 2.8 to 105.0 ± 33.7 ng/mL). Vanillin was showed positive correlations with guaiacol production in almost all strains (7094 T, R3, R111, and P1), with correlation coefficients of 0.97, 0.99, 0.82, and 0.87, respectively. We have reported different behaviour of A. acidoterrestris strains depending on juice type. Despite growth inhibition observed in some juices, enough guaiacol quantities to spoil the juice can be produced. This highlights the necessity of exploring strategies to prevent guaiacol production, even under growth restriction.

Quality Attributes of Ultrasound-Treated Prebiotic Fibre-Enriched Strawberry Juice

Strawberries are amongst the most desirable fruits with a rich flavour, appealing taste, high fibre content and many other health benefits. Diets rich in dietary fibre provide many health benefits. In the present work, strawberry juice was prepared in two batches, one with preservative sodium benzoate (treated) and another without (untreated). Prebiotic fibre i.e., apple pomace was added to both batches in concentrations of 5%, 8%, and 11%. Dietary fibre in both batches was analysed by enzymatic-gravimetric method. The additional analyses included pH, acidity, total soluble solids (TSS), colour, total phenolic content (TPC), antioxidant, ascorbic acid, anthocyanin, microbial and sensory parameters. Dietary fibre was increased significantly in all the treatments as well as TS, while pH and acidity were not affected. Ascorbic acid, anthocyanin, antioxidant, total phenolic content, and sensory analysis of treatment 2 (T2, 8% treated) showed the best results. The microbial load on the other hand increased more in the untreated batch. The T2 treatment of both the batches was given ultrasound treatment. The sonication temperature (20 oC), frequency (20 kHz), and power (650 W) were kept the same, and the time was varied (0, 15, 30, 45, and 60 minutes). Dietary fibre showed a slight increase as fibre became more soluble by cavitation in sonication while pH acidity and TSS were not significantly affected. Anthocyanin increased, but only at lower sonication times. Antioxidants, total phenols, and colour and sensory parameters were significantly improved with sonication time. Similarly, the microbial load was reduced significantly.

High-Power Ultrasound (HPU) and Pulsed Electric Field (PEF) in the Hurdle Concept for the Preservation of Antioxidant Bioactive Compounds in Strawberry Juice-A Chemometric Evaluation-Part II.

In this work, the influence of high-power ultrasound (HPU) followed by pulsed electric field (PEF) in the hurdle concept (HPU + PEF) on the content of biologically active compounds (BACs) and antioxidant activity in strawberry juices stored at 4 °C/7 days was investigated. The HPU was performed with an amplitude of 25% and pulse of 50% during 2.5, 5.0 and 7.5 min, while the PEF was performed with an electric field strength of 30 kV cm-1 and frequency of 100 Hz during 1.5, 3 and 4.5 min. The results obtained indicate that the synergy of the mechanisms of action for technologies in the hurdle concept plays a critical role in the stability of BACs and antioxidant activity. Juices treated with HPU + PEF hurdle technology and kept at 4 °C for 7 days showed a statistically significant decrease in all BACs, antioxidant capacity and pH. Shorter HPU + PEF treatment times favored the preservation of BACs in juices. Regarding total phenolic compounds, flavonols, condensed tannins and antioxidant capacity, optimization of hurdle parameters showed that a shorter HPU treatment time of 2.5 min provided the best yield of these compounds. In summary, by optimizing and adjusting the parameters of the HPU/PEF technology, it is possible to produce functional strawberry juice.

Fermentation of whey-derived matrices by Kluyveromyces marxianus: alcoholic beverage development from whey and fruit juice mixes.

This research paper addresses the hypotheses that Kluyveromyces marxianus can be cultured with good alcohol production on different whey-derived matrices, and that the fermented product can be used in order to develop alcoholic beverages with acceptable sensory characteristics by mixtures with yeast-fermented fruit-based matrices. Growth and fermentative characteristics of Kluyveromyces marxianus LFIQK1 in different whey-derived matrices were explored by culturing (24 h, 30°C) on reconstituted whey, demineralized whey, heat-treated whey and milk permeate media. High lactose consumption, ethanol production and yield were observed. Reconstituted whey matrix was selected for mixing with orange or strawberry juices fermented using Saccharomyces cerevisiae to obtain alcoholic beverages (W-OR and W-ST, respectively). Consumer evaluation of beverages was performed using acceptability and Check-All-That-Apply (CATA) questions. Good acceptance was observed, significantly higher for W-ST than for W-OR. CATA questions gave information about organoleptic characteristics of beverages. Penalty analysis showed W-R and W-ST were positively associated with smooth/refreshing and fruity/natural, respectively. Liking was represented, accordingly with penalty analysis, by natural/refreshing. A novel alternative for utilization of whey and whey-related matrices by alcoholic beverages production with natural ingredients is presented.

Effect of Strawberry Juice (Fragaria Ananassa) on Mechanical Properties of Nanofilled Composite Resins


 Introduction: Nanofilled composite resins have small filler particles size (1-100 nm). Its mechanical properties consist of hardness, surface roughness, and water absorption. Composite resins easily degraded by acid pH because it contains polymer with unstable bonds. Degradation can cause water absorption. It can be scratched more easily if they have low hardness. Rough surfaces can cause the risk of plaque formation, secondary caries, discoloration, damage to the surface of the patch, reduces resistance, accelerates abrasion, and can cause irritation to the surrounding soft tissue. Objective: To analyze the effect of mechanical properties (water absorption, hardness, and surface roughness) on nanofilled composite resins after strawberry juice (Fragaria ananassa) immersion. Methods: This research was a laboratory experimental with post-test and control group design. Forty cylindrical samples of nanofilled composite resins Filtek Z350XT (3M ESPE) (10mm x 2 mm) were divided into four groups: water absorption group, hardness tested group, surface roughness tested group, and control group. Surface roughness tested group and hardness tested group were immersed in strawberry juice each 10 mL for 2 hours a day and repeated for 12 days. After 10 and 12 days of immersion, hardness tested group, surface roughness tested group, and control group will be measured using surface roughness test and hardness test. Water absorption test will be carried out before immersion and after 10 and 12 days of immersion. Results: One Way ANOVA statistical test on surface roughness test showed a p-value of 0.001 (p<0.05) and the water absorption test show a p-value of 0.983 (p>0.05). Post Hoc Tukey test had significant difference of roughness tested on day 12 and control group with a p-value of 0.01 (p<0.05). Conclusions: Strawberry juice increases surface roughness of nanofilled composite resins after 2 hours immersion for 12 days in comparison with control group.

The Effect of Strawberries as a Natural Teeth Whitening Agent on Tooth Surface Roughness: In Vitro Study

Teeth whitening due to discoloration can be achieved by methods of bleaching. The material used in bleaching conventional methods can have effects on hard tooth tissue, such as increasing tooth surface roughness. Strawberries (Fragaria x ananassa) have long been known for being effective in whitening teeth. The aim of the research was to determine the effect of strawberries as a natural teeth whitening agent on tooth surface roughness in vitro. This research is an in vitro experiment. The samples were 24 first premolars of the upper jaw and lower jaw, which were divided into two groups. Group 1 (strawberry juice 100%) and group 2 (carbamide peroxide 10%). Testing tooth surface roughness using tools surface roughness tester, then the data was analyzed using statistical test paired t-test and Mann-Whitney. The results of the study showed that the mean and standard deviation of tooth surface roughness before and after application of strawberry fruit juice was 0.37 ± 0.156 and 0.22 ± 0.129, while the 10% carbamide peroxide group obtained the value of tooth surface roughness before and after application was 0.36 ± 0.118 and 0.37 ± 0.263.

Composition of free sugars and organic acids in Japanese strawberry cultivars and their influence on the perception of sweetness and sourness.

This study aimed to determine the extent of variations in the ratio of major free sugars to total sugars and major organic acids to total organic acids in strawberry juice with cultivar and harvest season and investigate whether these differences affect the perceived intensity of sweetness and sourness. Eight Japanese strawberry cultivars were simultaneously grown and harvested in different seasons for sugar and organic acid content analyses. In addition, simulated strawberry juices, containing equal total amounts of sugars and organic acids but in different ratios, were prepared based on their analytical values. The perceived intensities of sweetness and sourness of the juices were subjected to sensory evaluation. The results showed a wide range of sucrose compositions, ranging from almost zero to the highest ratio of 36.7% to total sugar. Glucose and fructose were present in approximately equal amounts, with a slight inclination toward more fructose. For organic acids, the highest ratio of citric acid was 87.6%, the lowest was approximately 60.1%, and the remainder comprised malic acid. The results of the sensory evaluation using simulated strawberry juice indicated that sweetness and sourness were significantly more pronounced as the ratio of sucrose to total sugar and the ratio of malic acid to total organic acid increased, respectively. These results suggest that it is essential to consider not only total soluble solids and titratable acidity but also the composition of the sugars and organic acids comprising them when evaluating strawberry taste. PRACTICAL APPLICATION: Total soluble solids and titratable acidity have been used to evaluate strawberry taste; however, how the composition and ratios of the sugars and organic acids that comprise them affect the taste is unclear. This study revealed that, for sugars, an increase in the proportion of sucrose resulted in a stronger perception of sweetness, and for organic acids, an increase in the proportion of malic acid resulted in a stronger perception of sourness. These findings are expected to be useful in future studies evaluating strawberry taste and palatability.

In Vitro Antioxidant Activity, Bioaccessibility, and Thermal Stability of Encapsulated Strawberry Fruit (Fragaria × ananassa) Polyphenols.

Bioactive compounds in red fruits, such as strawberries, are vulnerable to digestion, and encapsulation has become an alternative for their protection. This study aims at encapsulating strawberry juice (SJ) by freeze-drying with pea protein and okra mucilage (SJPO), pea protein and psyllium mucilage (SJPP), and pea protein, psyllium mucilage, and okra mucilage (SJPPO) and investigating the in vitro release. The highest encapsulation efficiency was observed in capsule SJPPO (95.38%) and the lowest efficiency in SJPO (82.45%). Scanning electron microscopy revealed an amorphous glassy structure for the structure of the strawberry microcapsules, and X-ray diffraction confirmed that observation. However, X-ray diffraction further showed that SJPPO was crystalline, indicating a tighter crosslinking density than the other microcapsules. Fourier transform infrared spectroscopy showed peaks at 3390 and 1650 cm-1, confirming the presence of polyphenols and polysaccharides in the strawberry microcapsules. Thermal stability was higher for SJPPO, and the observed thermal transitions were due to the bonds formed between the polymers and polyphenols. Pelargonidin 3-glucoside, cyanidin 3-glucoside, cyanidin, delphinidin, malvidin 3-glucoside, ellagic acid, chlorogenic acid, catechin, and kaempferol were identified in the strawberry microcapsules. Digestion affected the compounds' content; the bioaccessibility for SJ was 39.26% and 45.43% for TPC and TAC, respectively. However, encapsulation improved the bioaccessibility of both TPC (SJPP, 51.54%; SJPO, 48.52%; and SJPPO, 54.39%) and TAC (SJPP, 61.08%; SJPO, 55.03%; and SJPPO, 71.93%). Thus, encapsulating pea protein isolate, psyllium mucilage, and okra mucilage is an effective method to facilitate targeted release and preserve the biological activities of fruits.

Enhancing the qualitative and nutritional properties of strawberry juice through chitosan treatment

SummaryStrawberry (Fragaria x ananassa Duch.) belongs to the Rosaceae family. The fruit is very beneficial, with a delicious taste, attractive colour, and high vitamin and mineral content. The effect of chitosan on juice's transparency and phytochemical properties from the Camarosa cultivar was evaluated. Using chitosan as a clarifying agent for strawberry juice significantly reduced turbidity, phenolic content, flavonoids, protein and antioxidant properties. In contrast, the quantity of soluble solids, titratable acidity, pH, folate, vitamin C, anthocyanin and carbohydrates showed no significant changes. Changes were also observed in the colour‐related parameters of the juice. In order to assess potential contamination in strawberry fruit, the levels of heavy metals and pesticide residues were analysed separately using ICP and GC–MS techniques. There was a significant reduction in the levels of Cu, As, Co, Pb and Cd in strawberry juice after treatment with chitosan. Reducing heavy metals in fruit juice using chitosan helps improve the fruit juice's safety, nutritional properties and health benefits. It can be posited that chitosan affords the production of a more nutritious and healthier fruit juice as compared to natural strawberry fruit. Using chitosan as a clarifying agent produces a juice with extraordinary clarity, improves the safety, health benefits and nutritional value, and produces a consumer‐friendly product.

Pulsed Electric Field (PEF) and High-Power Ultrasound (HPU) in the Hurdle Concept for the Preservation of Antioxidant Bioactive Compounds of Strawberry Juice-A Chemometric Evaluation-Part I.

This work investigated the influence of pulsed electric field (PEF) and high-power ultrasound (HPU) combined with hurdle technology to preserve the bioactive compounds (BACs) content and antioxidant activity in stored strawberry juices. PEF was performed at 30 kV cm-1, 100 Hz during 1.5, 3, and 4.5 min, while HPU was performed at 25% amplitude and 50% pulse during 2.5, 5.0, and 7.5 min. Total phenols and hydroxycinnamic acids were the most stable BACs during the hurdle treatment without influence of the duration of both treatments, while flavonols and condensed tannins showed a significant stability dependence with respect to the duration of both treatments. Total phenols were also stable during storage, in contrast to the individual groups of BACs studied. A chemometric approach was used to optimize the parameters of the hurdle treatments with respect to the highest level of BACs and the antioxidant activity of the treated juices. In general, shorter treatment times in the hurdle approach resulted in better stability of BACs and antioxidant activity. The hurdle technology investigated in this study has the strong potential to be an excellent concept for optimizing the operating parameters of PEF and HPU technologies in the preservation of functional foods.

Bio-ethanol Production from Strawberry by Saccharomyces cerevisiae in Repeated Batch Abstract

Bio-ethanol, is considered the cleanest fluid fuel, and can be a dependable substitution to non-renewable energy sources. The maturation of sugar parts of plant materials produces it. Due to their high sugar content and abundance of nutrients, berries are thought to be an excellent source of fermentation products. This examination saw how well the yeast "Saccharomyces cerevisiae" created ethanol from strawberries (Fragaria ananassa) in rehashed bunches. According to the findings, strawberry juice had a total sugar concentration of 41.87 g/l. The final bioethanol percentage, ethanol yield, and maximum productivity were, respectively, 6 g/l/h (g ethanol per liter of strawberry juice per hour), 35 g/l (g ethanol per liter of raspberry juice), and 7 g/l (g ethanol per liter of strawberry juice).

Antiviral activity of copper contact surfaces against MS2 coliphage and hepatitis a virus.

Viral diseases can be indirectly transmitted by contaminated non-food contact surfaces to final food products by cross-contamination. The interaction of metal surfaces and viruses, MS2 coliphage and hepatitis A virus (HAV), was investigated for strategy development in decreasing this transmission risk. MS2 deposited onto stainless-steel surface was stable but inactivated at 0.95 log10 PFU min-1 on 99.9% copper surfaces. Greater copper-inactivation of MS2 was observed in (a) simple media (PBS) than protein-rich media (beef extract buffer), and (b) acidic than pH≥6.8 environments. Among food matrices (strawberry juices and beef broth), the greatest MS2 inactivation by copper occurred in filtered strawberry juice at pH 3.5. At a reduction of 0.17 log10 PFU min-1, HAV survived longer than MS2 on copper by FRhK-4 cell infectivity assay. The inactivation of virus on copper surfaces was greater in acidic viral surrounding environments and in simple PBS medium. In the same 99% PBS medium, MS2 may not be an appropriate surrogate for HAV when assessing viral inactivation on copper surfaces.

The Hypoglycemic and Hypolipidemic Effects of Polyphenol-Rich Strawberry Juice on Diabetic Rats.

Obesity and diabetes are some of the most important modern health problems requiring simple preventative or palliative measures using dietary means. This study investigated the impact of strawberry juice on diabetic rats. Diabetes was induced in rats using a single intraperitoneal injection of 50mg/kg streptozotocin (STZ). Fifty male rats were divided into five groups: normal control (NC), strawberry juice only (S), diabetic control (DC), and two diabetic groups treated with strawberry juice (DC + S) or metformin (DC + met). Rats were administered a single dose of both strawberry juice and oral metformin, and biochemical and histological analyses were conducted. The experiment was conducted in compliance with the Ethics Committee's regulations for the care and utilization of animals, microorganisms, and living cell cultures in education and scientific research at the Faculty of Agriculture, Minia University (MU/FA/006/12/22). Treatment of diabetic rats with strawberry juice led to a significant decrease in blood glucose. Insulin levels were also significantly increased, while lipid profiles were lowered in the diabetic rats treated with strawberry juice. Carbohydrate metabolism enzymes and antioxidant enzyme activities in the treated rats were restored to normal levels, and the levels of lipid peroxidation and proinflammatory cytokines were notably reduced. The microstructure of pancreatic and liver cells in diabetic rats was also improved with strawberry juice treatment. In addition, HPLC analysis revealed that strawberry juice was rich in flavonoids and phenolic compounds and exhibited potent antioxidant activity. These findings suggest that strawberry juice has considerable hypoglycemic and hypolipidemic effects on rats with diabetes which may be used in human after further investigations.

Evaluation of antioxidant capacity in different food matrices through differential pulse voltammetry and its correlation with spectrophotometric methods

Differential pulse voltammetry (DPV) and spectrophotometric methods were used to evaluate the antioxidant capacity (AC) in strawberry and orange juice, soluble coffee, rosemary extract, red wine, and sparkling white wine. The AC through spectrophotometric methods showed the following trend in solid foods, coffee > rosemary extract, and red wine > strawberry juice > orange juice > sparkling white wine in liquid samples. Charge measurements by DPV, presented in equivalent units of Trolox and gallic acid, showed the same trend in liquid samples; however, for solid samples, the AC of rosemary extract was greater than that of coffee. The charge expressed in equivalent units showed a high, positive, and significant correlation (p < 0.001) with total phenols (0.7919), FRAP (0.8875), and ABTS (0.8366). The proposed electrochemical technique proves to be a fast, reliable, and environmentally friendly alternative or complement to evaluate antioxidant capacity in food, which is not affected by the turbidity or color of the samples.Graphical abstract

The effect of using pomegranate and strawberry juices with red beet puree on the physicochemical, microbial and sensory properties of yoghurt

There is currently a growing interest in creating dairy products fortified with natural fruits containing (phenolic and antioxidant compounds) and safe for human consumption. Therefore, this trend was applied in the current study, where a mixture of red beet puree with pomegranate and strawberry juices were used in the manufacture of yoghurt. The effect of supplementing yoghurt with the previous mixture on the physicochemical, microbiological properties, color, antioxidant activity, total phenolic content, reduced sugars, was studied. The use of fruit juices had slightly significant effect on the acidification rate of milk and the basic physical and chemical properties of the resultant yoghurt, but it increased slightly the red color. The total phenol content and the antioxidant activity were increased in yoghurt containing the mixture of fruit than in control one. Microbiological results revealed that the counts of lactic acid bacteria were increased in all treatments during storage and reached the maximum after 7 days of storage as slightly lower counts were recorded in the control treatment than in the other treatments, when fresh and during the storage period. All treatments were free from coliform and yeast and molds when fresh but it were noticed in all treatments at the 7 day. Organoleptic examination indicates that fruit treatments yoghurt gained the higher significant (p ≤ 0.05) scores as compared to control, when fresh and during storage period. Generally, results of this study show that the use of the mixture of the former fruits may be applied to produce a functional yoghurt rich in phenolic components, antioxidants activity and nutrients.

Fecal fermentation and high-fat diet-induced obesity mouse model confirmed exopolysaccharide from Weissella cibaria PFY06 can ameliorate obesity by regulating the gut microbiota

Obesity associated with diet and intestinal dysbiosis is a worldwide public health crisis, and exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) have prebiotic potential to ameliorate obesity. Therefore, the present study obtained LAB with the ability to produce high EPS, examined the structure of EPS, and explained its mechanism of alleviating obesity by in vivo and in vitro models. The results showed that Weissella cibaria PFY06 with a high EPS yield was isolated from strawberry juice, and pure polysaccharide (PFY06-EPS) was purified by Sephadex G-100. The structural characteristics of PFY06-EPS showed that the molecular weight was 8.08 × 106 Da and composed of α-(1,6)-D glucosyl residues. An in vitro simulated human colon fermentation test demonstrated that PFY06-EPS increased the abundance of Prevotella and Bacteroides. Cell tests confirmed that PFY06-EPS after fecal fermentation inhibited fat accumulation by promoting the secretion of endogenous gastrointestinal hormones and insulin and inhibiting the secretion of inflammatory factors. Notably, PFY06-EPS reduced weight gain, fat accumulation, inflammatory reactions and insulin resistance in a high-fat diet-induced obesity mouse model and improved glucolipid metabolism. PFY06-EPS intervention reversed obesity-induced microflora disorders, such as reducing the Firmicutes/Bacteroides ratio and increasing butyrate-producing bacteria (Roseburia and Oscillibacter), and reduced endotoxemia to maintain intestinal barrier integrity. Therefore, in vivo and in vitro models showed that PFY06-EPS had potential as a prebiotic that may play an anti-obesity role by improving the function of the gut microbiota.