Fruit Matrix Research Articles

The Functional Carbonated Beverage Properties of Guabiroba Juice Using the Ice Fraction from Gravitational Block Freeze Concentration

The freeze concentration of liquid foods generates a by-product that has few academic studies and no industrial application: the ice fraction of each concentration stage. Sugar-free carbonated beverages were produced from the addition of 20% residual ice fraction (stage 1—I120 and stage 2—I220) of the gravitational block freeze concentration process, and the result was compared with a control beverage produced with 20% guabiroba juice (J20). The physicochemical properties, carotenoid content, total phenolic content (TPC), vitamin C, and antioxidant activity were analyzed for all samples. There was no significant difference between J20 and I220 for the total solid content and total soluble solids. For the total phenolic compounds (TPC), the I220 content was 151.3% higher than that of the original juice J20 and, for antioxidant activity, 295.8% higher for ABTS and 130.2% higher for DPPH. The I220 beverage presented 159% more vitamin C content than the beverage containing juice (J20). The same behavior was observed for each carotenoid content, with 168% more for the I220 sample. The total color difference revealed no difference visible to the naked eye for the three formulated beverages (∆E < 3.0; p < 0.05). The promising results of the bioactive compounds from guabiroba juice retained in the ice fraction can add value to this process waste in the formulation of new products due to the remaining functional appeal of the original fruit matrix.

Quantitative Analysis of Isopimpinellin from Ammi majus L. Fruits and Evaluation of Its Biological Effect on Selected Human Tumor Cells.

Ammi majus L. (Apiaceae) is a medicinal plant with a well-documented history in phytotherapy. The aim of the present work was to isolate isopimpinellin (5,8-methoxypsoralen; IsoP) from the fruit of this plant and evaluate its biological activity against selected tumor cell lines. The methanol extract obtained with the use of an accelerated solvent extraction (ASE) method was the most suitable for the quantitative analysis of coumarins in the A. majus fruit matrix. The coumarin content was estimated by RP-HPLC/DAD, and the amount of IsoP was found to be 404.14 mg/100 g dry wt., constituting 24.56% of the total coumarin fraction (1.65 g/100 g). This, along with the presence of xanthotoxin (368.04 mg/100 g, 22.36%) and bergapten (253.05 mg/100 g, 15.38%), confirmed A. majus fruits as an excellent source of these compounds. IsoP was isolated (99.8% purity) by combined liquid chromatography/centrifugal partition chromatography (LC/CPC) and tested for the first time on its antiproliferative activity against human colorectal adenocarcinoma (HT29, SW620), osteosarcoma (Saos-2, HOS), and multiple myeloma (RPMI8226, U266) cell lines. MTT assay results (96 h incubation) demonstrated a dose- and cell line-dependent decrease in cell proliferation/viability, with the strongest effect of IsoP against the Saos-2 cell line (IC50; 42.59 µM), medium effect against U266, HT-29, and RPMI8226 (IC50 = 84.14, 95.53, and 105.0 µM, respectively), and very weak activity against invasive HOS (IC50; 321.6 µM) and SW620 (IC50; 711.30 µM) cells, as well as normal human skin fibroblasts (HSFs), with IC50; 410.7 µM. The mechanistic study on the Saos-2 cell line showed that IsoP was able to reduce DNA synthesis and trigger apoptosis via caspase-3 activation. In general, IsoP was found to have more potency towards cancerous cells (except for HOS and SW620) than against healthy cells. The Selective Index (SI) was determined, underlining the higher selectivity of IsoP towards cancer cells compared to healthy cells (SI = 9.62 against Saos-2). All these results suggest that IsoP might be a promising molecule in the chemo-prevention and treatment of primary osteosarcoma.

In vivo and ex vivo study on cell wall components as part of the network in tomato fruit during the ripening process.

Ripening is a process involving various morphological, physiological, and biochemical changes in fruits. This process is affected by modifications in the cell wall structure, particularly in the composition of polysaccharides and proteins. The cell wall assembly is a network of polysaccharides and proteoglycans named the arabinoxylan pectin arabinogalactan protein1 (APAP1). The complex consists of the arabinogalactan protein (AGP) core with the pectin domain including arabinogalactan (AG) type II, homogalacturonan (HG), and rhamnogalacturonan I (RG-I). The present paper aims to determine the impact of a disturbance in the synthesis of one constituent on the integrity of the cell wall. Therefore, in the current work, we have tested the impact of modified expression of the SlP4H3 gene connected with proline hydroxylase (P4H) activity on AGP presence in the fruit matrix. Using an immunolabelling technique (CLSM), an immunogold method (TEM), molecular tools, and calcium mapping (SEM-EDS), we have demonstrated that disturbances in AGP synthesis affect the entire cell wall structure. Changes in the spatio-temporal AGP distribution may be related to the formation of a network between AGPs with other cell wall components. Moreover, the modified structure of the cell wall assembly induces morphological changes visible at the cellular level during the progression of the ripening process. These results support the hypothesis that AGPs and pectins are required for the proper progression of the physiological processes occurring in fruits.

Effect of drying methods on free and bound phenolic compounds, antioxidant capacities, and bioaccessibility of Cornelian cherry

Cornus mas L. (Cornelian cherry, CM) fruits were dehydrated by solar-drying (SD) and freeze-drying (FD), and in addition to sugar and mineral contents, the free and insoluble-bound phenolics were determined in fresh and dried fruits. After subjecting the sample to simulated in vitro digestion, the change of free and bound phenolics at gastric and intestinal digestion steps was evaluated in fresh and dried CM fruits. In fresh CM fruits, the total phenolic content (TPC) was dominated by the bound fraction, whereas the contribution of free phenolics to the total content (free + bound) became more dominant (731–1439 mg GAE/100 g dw) in the dried fruits. The bioaccessibility (BI%) of TPC from fresh CM after digestion was 193%, whereas it was 18.60 and 48.02% for SD and FD fruits, respectively. The contribution free fraction to the total TPC value was around 28% in nondigested fresh samples and increased to 94% in digested samples; however, in dried samples, it was 64% prior to digestion and only increased to 70% in digested samples. A total of 17 phenolic compounds were identified in CM fruits: chlorogenic acid, caffeic acid, epicatechin, quercetin, cyanidin-3-O-glucoside, and pelargonidin 3-O-glucoside were only detected in the free fraction; gallic acid, vanillic acid, ferulic acid, and kaempferol were detected in higher amounts in the bound fraction. The quantity of detected phenolics in the nondigested sample generally decreased from the gastric to the intestinal stage of digestion. The release of phenolics from the fruit matrix and their degradation occurred simultaneously during digestion, and this could be affected by the state of the fruit, e.g., fresh or dried.Graphical abstract

Free and bound polar phenols in Corinthian currants (Vitis vinifera L., var. Apyrena)

Corinthian currant is a Greek dried fruit that accounts for approximately 3% of the dried vine fruit worldwide production; its consumption has been associated with health benefits in rodents and humans. In this study, Corinthian currant was evaluated for its free and bound polar phenol content; samples from six Greek cultivation regions were analyzed. Among others, ten compounds were identified for the first time as components of the Corinthian currant free polar phenol profile, using UHPLC-ESI/MS; Caftaric acid predominated (10.59 mg/100 g) followed by miquelianin (5.41 mg/100 g). Two procedures, both combining acid and alkaline hydrolysis but in reverse order, were comparatively evaluated for the release of bound phenols from the fruit matrix; both approaches were proven adequate for the Corinthian currant bound phenol determination. Phenolic acids and flavonoids constituted the Corinthian currant bound polar phenol fraction. p-Hydroxybenzoic acid was the major constituent of both the acid (6.81 mg/100 g) and the subsequent alkaline (4.85 mg/100 g) hydrolysates. Bound polar phenols may provide various health-promoting properties and this is the first study to investigate the bound phenols of Corinthian currant and apply an efficient method for their release.

How do the phenolics and amino acids affect the antioxidant, antidiabetic and antiglycation properties of selected fruit powders?

Fruit matrix modification caused by processing determines the reactivity of bioactives. In line with a new trend in foods development and nutrition, the study endeavored to recognize contribution of phenolics and amino acids from selected raw materials, i.e., Japanese quince, rosehip, haskap berry and blackcurrant in moderation of antioxidant, antidiabetic and antiglycation potential of freeze-dried powders. Qualitative and quantitative evaluation of phenolics and amino acids was performed for powdered fruit, pomace, juice and sugar-free juice products considered as different matrices. Phenolics’ groups differently influenced antidiabetic activity depending on the composition of the matrix in which they were present. Flavonols affected the ability to inhibit advanced glycation end products (AGEs) derived from methylglyoxal and l-arginine. The involvement of individual amino acids in antioxidant capacity was identified, pointing to ornithine presence as the most influential one. Free radical scavenging activity of freeze-dried powders contributed to effectiveness as AGEs inhibitors. Results provided an insight for powdered fruit product development, stressing that composition of fruit-based matrix is a key point for creation of potential functional properties.

Fabrication of poly-dopamine-modified magnetic nanomaterial and development of integrated QuEChERS method for 122 pesticides residue analysis in fruits

A rapid and accurate integrated QuEChERS method was established for the determination of multi-pesticide residues in fruits. Poly-dopamine-modified magnetic nanomaterial (Fe3O4-pDA) was homemade and characterized. The prepared Fe3O4-pDA has the functional group of absorbing the saccharides, and can be used as co-adsorbent with 3-(N, n‑diethyl amino) propyl trimethoxy-silane (PSA) in the developed integrated QuEChERS method to purify the fruit matrix, thus achieve the accurate determination of multi-pesticides residue. Grape was used as the representative sample to explore the influence of the salting out agent and each purification adsorbent on the pesticide recoveries. Under the optimized conditions, the proposed method showed good linearity for 92.6% of pesticides in the concentration range of 1–150 μg L−1 with method limit of quantitative (mLOQs) ranged from 10 to 18 μg kg−1. Spiked recoveries experiments were performed on four kinds of grapes and other fruits (apple, watermelon, pear, jujube and peach), in which satisfactory recoveries and precision were obtained for most of the pesticides. Meanwhile, comparison experiments also verified this method was superior to the traditional QuEChERS method in terms of convenient operation, high efficiency and low reagent consumption. The further real sample analysis was performed using this method, and the overall detection rate was 52%, while 2% of samples were exceeding the maximum residue limits. All results confirmed that the proposed method could be used for the rapid, simple, low-costing and effective analyses of trace multi-pesticides residue in fruit samples.

Effects of enzymatic treatment on the in vitro digestion and fermentation patterns of mulberry fruit juice: A focus on carbohydrates

The aim of this study was to investigate the effects of enzymatic treatments (pectinase, pectin lyase, and cellulase) on the in vitro digestion and fermentation characteristics of whole mulberry fruit juice. The analysis focused on changes in carbohydrate properties within the black mulberry fruit matrix during simulated digestion and fermentation. Human fecal microbiota were collected and introduced to the fruit matrix to monitor the fate of both soluble and insoluble polysaccharides during fermentation. The results revealed that enzymatic treatments enhanced the solubilization of carbohydrates from mulberry fruits, with pectinase showing the most significant effect. Throughout the process of in vitro digestion, there was a gradual increase in the percentage of solubilized carbohydrates from the mulberry juice substrate. The digested suspensions underwent dialysis to remove degradation fragments, and a lower quantity of carbohydrate in the enzyme-treated groups compared to the control. Polysaccharide populations with varying molecular weights (Mw) were obtained from the soluble fractions of mulberry residues for subsequent fermentation. An increase in Mw of soluble polysaccharides was detected by HPSEC during fermentation in certain cases. The gut microbiota demonstrated the ability to convert specific insoluble fractions into soluble components, which were subsequently subjected to microbial utilization. Enzymatic treatments during mulberry juice preparation can potentially positively impact health by influencing gut microbiota and short-chain fatty acid (SCFA) modulations. Enzymes could serve as valuable tools for producing functional fruit and vegetable juices, with the need to specify processing conditions for specific raw materials remaining a subject of further investigation.

Tetrahydrobenzo[h]quinoline derivatives as a novel chemotype for dual antileishmanial-antimalarial activity graced with antitubercular activity: Design, synthesis and biological evaluation

Derivatives with tetrahydrobenzo[h]quinoline chemotype were synthesized via one-pot reactions and evaluated for their antileishmanial, antimalarial and antitubercular activities. Based on a structure-guided approach, they were designed to possess antileishmanial activity through antifolate mechanism, via targeting Leishmania major pteridine reductase 1 (Lm-PTR1). The in vitro antipromastigote and antiamastigote activity are promising for all candidates and superior to the reference miltefosine, in a low or sub micromolar range of activity. Their antifolate mechanism was confirmed via the ability of folic and folinic acids to reverse the antileishmanial activity of these compounds, comparably to Lm-PTR1 inhibitor trimethoprim. Molecular dynamics simulations confirmed a stable and high potential binding of the most active candidates against leishmanial PTR1. For the antimalarial activity, most of the compounds exhibited promising antiplasmodial effect against P. berghei with suppression percentage of up to 97.78%. The most active compounds were further screened in vitro against the chloroquine resistant strain P. falciparum, (RKL9) and showed IC50 value range of 0.0198–0.096 μM, compared to IC50 value of 0.19420 μM for chloroquine sulphate. Molecular docking of the most active compounds against the wild-type and quadruple mutant pf DHFR-TS structures rationalized the in vitro antimalarial activity. Some candidates showed good antitubercular activity against sensitive Mycobacterium tuberculosis in a low micromolar range of MIC, compared to 0.875 μM of isoniazid. The top active ones were further tested against a multidrug-resistant strain (MDR) and extensively drug-resistant strain (XDR) of Mycobacterium tuberculosis. Interestingly, the in vitro cytotoxicity test of the best candidates displayed high selectivity indices emphasizing their safety on mammalian cells. Generally, this work introduces a fruitful matrix for new dual acting antileishmanial-antimalarial chemotype graced with antitubercular activity. This would help in tackling drug-resistance issues in treating some Neglected Tropical Diseases.

Field bioefficacy and residue dynamics of chlorantraniliprole (18.50% sc) in okra (Abelmoschus esculentus)

The okra fruit borer (Earias vittella) and sucking pests are a key limiting factor in okra cultivation due to their severe crop destruction behaviour. An experiment was conducted during 2019–20 to assess the bioefficacy of various new insecticides and persistence of chlorantraniliprole 18.50 sc residues in okra fruits at research farm of ICAR- Indian Institute of Vegetable Research, Varanasi, Uttar Pradesh. Among various treatments, chlorantraniliprole tested at 30 g a.i./ha was reported to be effective in reducing fruit damage by E. vittella (96%), as well as sucking pests infestation (87.81–1100%) with a significantly higher marketable fruit yield (8.88 t/ha) recorded under open field situations. Ethyl acetate was used to extract the chlorantraniliprole contaminants from the okra fruit matrix, and PSA and magnesium sulphate were used to clean up the matrix. The estimate for the limit of quantification (LOQ) was 0.01 mg/kg, and the average percent recoveries ranged from 83.67–89.00. The half-life was estimated 1.72 days. Based on the field bioefficacy against insect pests and residue status in okra fruits, it can be concluded that the chlorantraniliprole 30 g a.i./ha can be utilized in the okra ecosystem to successfully manage the sucking pest complex and fruit borer without posing any health risks to consumers.

Self-Emulsifying Micellization of Crude Extracts from Apple (Malus domestica cv. Anna), Plum (Prunus domestica cv. Satsuma), and Guava (Psidium guajava L.) Fruits.

Micellar microemulsions are thermodynamically stable self-emulsifying systems that have been used to successfully improve the low oral bioavailability of several bioactive phytochemicals, such as antioxidant polyphenols. However, most studies have reported the micellization of single-compounds or purified chemical fractions; thus, the stability, phytochemical-loading efficiency, and bioactivity of complex crude extracts remain largely unexplored. In this study, we evaluated the effects of micellar emulsification of tropical apple (Malus domestica cv. Anna), plum (Prunus domestica cv. Satsuma), and guava (Psidium guajava L.) extracts regarding particle size and stability, polyphenol-loading efficiency, antioxidant capacity, and cytotoxic activity in human and murine cells. Simple food-grade extraction protocols were implemented to obtain apple, plum, and guava extracts. Total polyphenols, flavonoids, and antioxidant activity (DPPH) were determined in the fruit extracts, and their polyphenol profile was further characterized by liquid chromatography (HPLC-DAD). The dried extracts were mixed into a food-grade, self-emulsifying system, and their cytotoxicity in human and murine cell lines was compared. Our research showed that complex fruit matrixes were successfully emulsified into thermodynamically stable polysorbate-based nanometric micelles with uniform size distribution and consistent pH stability, with potential applications in food and biomedical industries.

Structure-guided approach on the role of substitution on amide-linked bipyrazoles and its effect on their anti-inflammatory activity

A structure-guided modelling approach using COX-2 as a template was used to investigate the effect of replacing the chloro atom located at the chlorophenyl ring of amide-linked bipyrazole moieties, aiming at attaining better anti-inflammatory effect with a good safety profile. Bromo, fluoro, nitro, and methyl groups were revealed to be ideal candidates. Consequently, new bipyrazole derivatives were synthesised. The in vitro inhibitory COX-1/COX-2 activity of the synthesised compounds exhibited promising selectivity. The fluoro and methyl derivatives were the most active candidates. The in vivo formalin-induced paw edoema model confirmed the anti-inflammatory activity of the synthesised compounds. All the tested derivatives had a good ulcerogenic safety profile except for the methyl substituted compound. In silico molecular dynamics simulations of the fluoro and methyl poses complexed with COX-2 for 50 ns indicated stable binding to COX-2. Generally, our approach delivers a fruitful matrix for the development of further amide-linked bipyrazole anti-inflammatory candidates.

Supercritical CO2 pretreatment of date fruit biomass for enhanced recovery of fruit sugars

This study explores the use of supercritical CO2 (Sc-CO2) as an innovative and green approach for pretreating date fruits to enhance the total sugar yield by water-based extraction. The pretreatment step was investigated based on Box-Behnken factorial design to evaluate the influence of critical variables on the total sugar yield. Sc-CO2 conditioning of the date pulp was investigated by varying the pressure (10–20 MPa), temperature (25–50 °C), and contact time (30–120 min) in a batch setup. Temperature and pressure variables were identified as the significant parameters for the Sc-CO2 treatment. Optimization analysis showed a maximum total sugar yield of 74.1 g/100 g for Sc-CO2pretreated date pulp at 10 MPa and 46 °C for 59 min. Besides, the pretreatment mechanism involved major effects such as swelling, disruption, and explosion that favored the enhanced recovery of total sugars from the date fruit matrix during the extraction. SEM and XRD studies confirmed changes in the microstructure of the date pulp biomatrix before and after pretreatment. Therefore, the consecutive approach of Sc-CO2 conditioning followed by aqueous extraction appears to be an efficient and promising technique for the enhanced recovery of fruit sugars at relatively low temperatures and without the use of any toxic solvents.

Improved understanding and prediction of pear fruit firmness with variation partitioning and sequential multi-block modelling

Fruit firmness is a complex trait that develops throughout fruit development, including post-harvest, and is influenced by both ripening and dehydration. There is a wide interest in predicting the firmness with non-destructive sensing techniques such as spectral analyses. However, often used reference techniques, such as acoustic firmness (AF), limited compression (LC) and Magness-Tyler (MT), respond differently to dehydration and ripening. This study aims to detangle how the firmness of ‘Conference’ pears relates to dehydration and ripening and to model ripening-related firmness using non-destructive sensing. Hereto, a pear fruit matrix was created with varying firmness and dehydration levels. To model fruit firmness (LC and MT) with Vis-NIR spectroscopy and explore whether AF information could complement Vis-NIR spectroscopy, a sequential multi-block analysis was performed. Single block Vis-NIR spectral data were made multi-block by partitioning the variance in spectral data into acoustic-dependent and -independent parts. A variation partitioning based approach was also presented to select the best pre-processing operation for Vis-NIR spectral data modelling. Multi-block regression to predict firmness and classification modelling of pear fruit in different firmness classes was also practised. The obtained results led to enhanced insights into the different fruit firmness measures and the capability of Vis-NIR and acoustic for non-destructive fruit firmness prediction. The results can benefit the scientific community working in the domain of fruit optical spectroscopy and chemometric modelling.

Power Ultrasound-Assisted Impregnation of Apple Cubes with Vitamin B12

This work explores the use of ultrasound (US) as a means of intensifying the impregnation of apple cubes with vitamin B12 (cyanocobalamin). The effect of different US power densities (90 and 200 WL−1) and treatment times (5, 10, and 15 min) was evaluated, on vitamin load, vitamin stability, and physicochemical and microstructural properties of the fruit matrix. The US enhanced the impregnation producing high cyanocobalamin content products (0.12–0.19 mg vitamin/g db.). Vitamin losses in the sonication medium due to US application were not significant. Impregnated samples exhibited higher moisture and lower soluble solids with respect to the untreated fruit. Changes in chromatic coordinates were well correlated to vitamin uptake. Only at the highest treatment intensities (200 WL−1, 10, and 15 min) was a marked softening observed, which agreed with the microstructural changes observed in fruit tissues. Results permit US-assisted impregnation to be considered a promising technology in the preparation of vitamin B12 fortified apple cubes.

Influence of fruit-based beverages on efficacy of Lacticaseibacillus rhamnosus GG (Lactobacillus rhamnosus GG) against DSS-induced intestinal inflammation

Different lines of evidences from clinical, epidemiological and biochemical studies have established that optimal nutrition including probiotic and fruit phenolics can mitigate the risk and morbidity associated with some chronic diseases. The basis for this observation is the potential synergies that may exist between probiotic strains and different bioactive components of food matrices. This study was conceptualized to compare the efficiency of a probiotic strain in two different fruit matrices. Two fruits, viz., sea buckthorn (Hippophae rhamnoides) (SBT) and apples (Malus pumila) (APJ) were chosen and the anti-inflammatory effects of L. rhamnosus GG (ATCC 53103) (LR) fortified in SBT and APJ were analysed against dextran sulphate sodium (DSS) induced colitis in zebrafish (Danio rerio). The results showed that administration of probiotic (LR) fortified, malt supplemented SBT beverage (SBT + M + LR) had better restorative potential on the intestinal barrier function and mucosal damage, in comparison to LR fortified, malt supplemented APJ beverage (APJ + M + LR). SBT + M + LR demonstrated adequate anti-oxidant potential by enhancing the CAT, SOD, GPx and GSH activities, impaired due to DSS administration. The increase in the expressions of toll like receptor (TLR)-2, TLR-4 and TLR-5 induced by DSS were significantly inhibited by SBT + M + LR administration. Gene expression of pro-inflammatory markers, (NF-κB, TNF-α, IL-1β, IL-6, IL-8, CCL20, MPO and MMP9) were attenuated by SBT + M + LR treatment in intestinal tissues of DSS-treated zebrafishes. Notably, SBT + M + LR increased the expression of anti-inflammatory cytokine, IL-10. The study provides evidence that specific interactions between fruit matrix and probiotic strain can provide adjunct therapeutic strategy to manage intestinal inflammation.

Partial purification, characterization and kinetics of thermal inactivation of pectin methylesterase and polygalacturonase enzymes from Indian lemon (Citrus limon (L.)

The extraction, purification, and characterization of PME and PG were studied for lemon fruit. Enzymes were partially purified by anion-exchange chromatography using UNOsphere™ Q anion exchanger for lemon PME and DEAE Cellulose anion exchanger for lemon PG. A single band with a fold purity of 20.95 and 15.75 for PME and PG respectively was observed on SDS-PAGE. Molecular weights of partially purified fractions of PME and PG as exhibited by SDS-PAGE were 48 kDa and 95 kDa respectively. Optimum pH and temperature of partially purified lemon PME and PG were pH 9, pH 5 and 45 °C. The crude PME and PG extracts exhibited D-values of 120.57–63.79 and 185.72–29.18 min; Z-values of 15.11 and 16.50 °C; and activation energies (Ea) of 58.23 and 57.18 kJ/mol, respectively. The enzyme stability was not significantly influenced by the fruit matrix as reflected by Z and Ea values. D and Z-values of both the enzymes and microorganisms should be considered while designing thermal treatments to obtain a product with better shelf life.

Antimicrobial Cocktail Combining Specific Peptide Extracts from Native Probiotic Bacteria Hamper Adulteration of Ready-to-Eat Mango Wedges

Consumption of ready-to-eat chopped fruits sold in the streets is a concern, as such activities are outside the regulation and protection in most developing countries. Ready-to-eat mangos are commonly sold as wedges in plastic cups at ambient temperature by mobile vendors in Ecuador, thus they are prone to contamination by bacteria, which poses a safety issue of concern. This work aimed to evaluate the effect of several antimicrobial cocktails consisting of previously designed specific peptide extract combinations from two probiotic bacteria Lactobacillus plantarum UTNCys5-4 and Lactococcus lactis subsp. lactis UTNGt28, along with nisin, a commercial food additive, on mango wedges artificially inoculated with a logarithmic phase culture of a five-strain bacterial mixture (FSBM). Preliminary bacteriological analysis of mango wedges purchased from mobile vendors showed the presence of multiple antibiotic-resistant isolates such E. coli spp., Enterobacter spp., Shigella spp., Salmonella spp., along with yeasts and molds, indicating non-compliance with the food safety standards. The results revealed that two antimicrobial cocktails, T2 and T5, containing cell-free supernatant based (CFS) and precipitated peptides (PP) based cocktails from UTNCys5-4 and UTNGt28 strains applied at dose 1:3 (v/v), were the most efficient combinations that inhibited the colonization of total bacterial counts with 56.03% and 55.61% in mango wedges stored with refrigeration. The reduction of total E. coli counts was 64.93%, while Salmonella and Shigella counts were reduced by 98.09% and 97.93%, respectively, when mango wedges were treated with T5-cocktail. The commercial nisin inhibited total Salmonella spp. counts by 40.13%, while E. coli spp. and Shigella spp. diminished by 28.20% and 37.22%, respectively. Moreover, we showed that T5 but not T7 (nisin) damaged the target cell integrity, thereby eventually inhibiting their growth and reproduction. The selected antimicrobial cocktails exerted a bacteriolytic effect by killing the FSBM simultaneously in a fruit matrix and preventing their accumulation in mango wedges. Furthermore, there is a possibility of using peptide combinatorial treatments to combat drug-resistant bacteria in ready-to-eat fruits.

Measurement and PC-SAFT Modeling of the Solubility of Gallic Acid in Aqueous Mixtures of Deep Eutectic Solvents

Deep eutectic solvents have appeared as potential solvents for improving the extraction of polyphenols from vegetable or fruit matrixes. Since gallic acid is abundant in these sources, it is considered as a typical standard for quantifying their total polyphenol content after extraction with solvents. However, there are no extensive studies on the solubility behavior of gallic acid in different solvents or deep eutectic solvents. Thus, in this work, the solubility of gallic acid is measured in pure water; aqueous solutions of different hydrogen bond donors such as ethylene glycol, levulinic acid, and glycerol; and aqueous mixtures of deep eutectic solvents using choline chloride as the hydrogen bond acceptor and ethylene glycol, levulinic acid, and glycerol as the hydrogen bond donors. All of the measurements were performed at 293.15, 303.15, and 313.15 K and at 101.3 kPa and were validated by comparing the solubility of gallic acid in water from the literature. Results suggest that a 50 wt % aqueous solution of deep eutectic solvent based on ethylene glycol or glycerol improves the gallic acid solubility compared with a 50 wt % aqueous solution of its corresponding hydrogen bond donor. The deep eutectic solvent containing levulinic acid acts as the best aqueous mixture for gallic acid dissolution. Nondissolved gallic acid was measured after equilibrium using powder X-ray diffraction, showing that its structure does not change upon mixing with all of the liquid mixtures. All of the solid–liquid equilibrium results were accurately modeled with perturbed-chain statistical associating fluid theory (PC-SAFT).

Determination of α‐dicarbonyl compounds and 5‐hydroxymethylfurfural in commercially available preserved dried fruits and edible seeds by optimized UHPLC–HR/MS and GC–TQ/MS

Thermal processing, Maillard reaction, and caramelization favors the formation of α-dicarbonyl compounds during thermal dehydration of fruits and edible seeds roasting, which are extensively discussed as precursors of different undesirable compounds such as 5- hydroxymethylfurfural. Different studies have focussed on prevalence of α-dicarbonyl compounds and determination of 5-hydroxymethylfurfural from simple food matrices. However, still extensive studies are needed to be carried out for their determination from these complex food matrices for human awareness. In this study, the prevalence of α-dicarbonyl compounds and 5-hydroxymethylfurfural was investigated using an optimized UHPLC–HR/MS after ortho-phenylenediamine derivatization, and by an optimized GC–TQ/MS, respectively. Eight different categories of dried fruits and four categories of edible seeds were analyzed for prevalence of 3-deoxyglucosone (3-DG), glucosone (G), glyoxal (GO), methylglyoxal (MGO), and 5-hydroxymethylfurfural (5-HMF). Significantly higher prevalence of 3-DG was shown in raisins with concentration of 43.36 ± 1.16 mg/kg; however, 5-HMF has shown significantly higher concentrations (165.90 ± 4.41 mg/kg) in dried mango category. Moreover, edible seeds category has shown higher prevalence of 3-DG with 3.80 ± 0.28 mg/kg in hazelnuts and 75.44 ± 3.13 mg/kg of 5-HMF from peanuts. Interestingly, higher concentration of 5-HMF was determined in all analyzed samples than 3-DG, indicating a relation between the conversion of α-dicarbonyl compounds into 5-HMF during the dehydration process or roasting of dried fruits and edible seeds, respectively. Moreover, these methods were also validated in terms of recovery, specificity, accuracy, limit of detection, limit of quantification, and relative standard deviation for all analyzed compounds. Practical Application This study has conducted to get awareness about formation of harmful compounds during processing of fruits and edible seeds in order to get them preserved for long time and to increase their taste properties. This study has clearly stated the prevalence of alpha-dicarbonyl compounds and 5-hydroxymethylfurfural which can later convert into more toxic compounds upon changes in their conformation. Hence, the routine or excessive usage might be health hazardous for us. Moreover, companies should also apply more careful processing conditions posing less effect on fruit matrix.