Acidity Of Phenols Research Articles

Optimised Formulation of a New Sweet Apricot Kernel-Enriched Yoghurt: Assessment of Physicochemical, Sensory and Antioxidant Properties.

The addition of sweet apricot kernel powder, a by-product of apricot processing, to yoghurt appears to be particularly interesting option for the innovation of new food products. This study focuses on the formulation of a novel yoghurt enriched with sweet apricot kernel powder, sugar and milk powder. Different yoghurts were prepared by mixing sweet apricot kernel powder, sugar and milk powder as ingredients based on the simplex-centroid mixture design. The optimisation process took into account the physicochemical, antioxidant and sensory properties of the yoghurt. The results showed that the optimum values of sugar, milk powder and apricot kernel powder were 3.07, 2.16 and 2.77 %, respectively. The physicochemical assays showed that the addition of apricot kernel powder led to a significant increase in total phenolic content, antioxidant activity, syneresis, viscosity and acidity. The addition of sugar and milk powder also had a significant effect on the taste, texture and consistency of the yoghurt. Moreover, the enrichment of the product with apricot kernel powder significantly influenced the colour, odour, taste, texture and consistency. In conclusion, the optimised yoghurt enriched with apricot kernel had an interesting phenolic content and antioxidant properties with sensory acceptability, while reducing the amount of sugar and milk powder. This confirms the potential of using sweet apricot kernels as an ingredient in yoghurt production. The use of a simplex-centroid mixture design to optimise a new yoghurt formulation enriched with sweet apricot kernels shows significant improvements in total phenolic content, antioxidant activity and sensory acceptability. In addition, less sugar and milk powder is needed. The addition of sweet apricot kernels to yoghurt is therefore a new approach to improving its nutritional value and sensory appeal.

Consumption of Citric Acid by Bees Promotes the Gland Development and Enhances Royal Jelly Quality.

The glands of bees are responsible for generating and secreting various biologically active substances that significantly impact bee physiological health and adaptability. This study aimed to investigate the effects of adding citric acid (CA) to bee feed on gland development and royal jelly quality. By formulating feed with varying proportions of CA, evaluation was undertaken of pollen feeding by honeybees under laboratory conditions, along with the impact of CA on the development of major glands, to determine suitable addition proportions. Further optimization of the CA proportion involved feeding colonies and evaluating royal jelly production and quality. The results indicated that feed containing 0.75% CA significantly extended the lifespan of bees and increased their pollen consumption. Gland development in bees showed a positive correlation with CA addition within the range of 0.25% to 0.75%, especially at 0.50% and 0.75%, which notably accelerated the development of mandibular, hypopharyngeal, and cephalic salivary glands, with active proliferation and differentiation of glandular cells and maintenance of normal gland size and morphology. CA added to feed stimulated vigorous secretion of wax glands in worker bees, resulting in prolific wax construction. Colonies consuming feed containing 0.50% CA produced royal jelly with significantly reduced moisture and total sugar content and increased levels of 10-HDA, total phenolic acids, total proteins, and acidity. These findings demonstrate that CA consumption significantly prolongs bee lifespan, increases consumption, promotes gland development, and enhances royal jelly quality. This research provides theoretical guidance for beekeeping practices and feed development, contributing to the sustainable advancement of apiculture.

Chemical and Spectroscopic Characteristics of Humic Acids Under No-Tillage and Forest Systems

ABSTRACT This study aims to evaluate the no-tillage system (NT) with different implantation times and vegetation cover on changes in the chemical and structural compositions of soil humified organic matter. Five areas with different NT management histories were studied; for 6 (NT6), 14 (NT14), 22 (NT22) years with succession of soybean/corn crops; for 12 years and 4 more years with corn and Brachiaria (NT+B), pasture for 39 years and native forest. Soil samples were collected at the depths of 0.0–0.05 and 0.05–0.10 m. The changes in the quality of humic acid (HA) were evaluated by several chemical techniques (total organic carbon (TOC), fulvic acid fraction (FA), humic acid fraction (HA) and humin fraction (HU), ionizable functional groups, elemental composition) and spectroscopic techniques (UV–Vis absorption, fluorescence, and Fourier transform mid-infrared photoacoustic spectroscopy, called FTIR-PAS). On the surface, the TOC, carbon of the HA and HU fractions, total acidity, phenolic acidity, Carbon, Nitrogen, Sulfur, Hydrogen and Hydrogen/Carbon ratio were higher in the areas of forest, pasture and NT22. On the subsurface, the responses are the same as on the surface. However, the NT22 system presents higher FA, HA, carboxylic acidity and humification degree (HD). UV–Vis absorption spectroscopy, fluorescence spectroscopy and FTIR-PAS can discriminate soils under different managements and under natural conditions. Agronomic practices have strongly affected the soil organic matter, in which the NT promotes the formation of HA with characteristics closer to those of the forest, as the implantation time increases, such as 22-year-old NT and pasture. This indicates that care must be taken in managing the no-till system to maximize its potential to promote stabilization of organic matter, thereby contributing to carbon sequestration.

Re-Examining Cannabidiol: Conversion to Tetrahydrocannabinol Using Only Heat.

Introduction: In the last decade, the market for Cannabidiol (CBD) has grown to become a near $2 billion dollar industry in the United States alone. This growth can be attributed to a growing social acceptance of marijuana, a more detailed understanding of many health benefits attributed to cannabinoids, and the low cost and wide availibility of hemp-derived cannabinoids. Due to the complex legal histories of marijuana and cannabinoids, the stability and safety of CBD is still an area of interest as research has been restricted globally. Conversion of CBD to its psychoactive isomers, most notably delta-9-Tetrahydrocannabinol (Δ9-THC), presents a significant safety issue for consumers and producers of CBD products. Methods: Previous studies investigating the stability of CBD have focused mainly on replicating conditions experienced during long-term storage at room temperature or lower. Here, we report the thermal stability of CBD at 175°C. Dynamic 1H-NMR experiments and computational electronic structure calculations were used to characterize possible reaction paths from CBD to THC. Results: After 30 minutes of heating, Δ9-THC was produced in detectable amounts in aerobic and anaerobic conditions without an acid catalyst. Conclusions: Our findings support an energetically feasible reaction route that is favorable due to both an increase in phenol acidity at high temperatures and the presence of intramolecular OH-π hydrogen bonding.

Enzymatic Extraction of Sapodilla (Manilkara achras L.) Juice: Process Optimization and Characterization

Conventional treatment of sapodilla pulp yields very viscous, turbid, and low juice recovery. Sapodilla processing for juice requires liquefying enzyme that leads to rectifying flow of juice. This study was conducted to optimize the enzymatic pectolytic conditions of sapodilla fruit processing to extract maximum juice using a central composite design (CCD). The effect of processing variables on recovery of juice, total soluble solids (TSS), viscosity, clarity, and L-value along with physicochemical analysis was investigated. The optimized processing conditions were pectinase concentration (0.120%) at 42.02°C for 167.83 min resulting in juice recovery (62.08 ± 0.38%), viscosity (4.81 ± 0.02cP), TSS (21.48 ± 0.19 °Brix), clarity (0.72 ± 0.05%T), and L-value (28.79 ± 0.96). Optimized sapodilla juice showed higher filterability (24.16 ± 1.04 min−1), conductivity (69.46 ± 0.30 S/m), total phenolic content (35.86 ± 0.60 mg/100 mL), ascorbic acid (6.38 ± 0.58 mg/100 mL), moisture content (84.85 ± 0.21% WB), and titratable acidity (0.143 ± 0.0% citric acid) as compared to control sample (60.5 ± 1.80 min−1, 30.43 ± 0.35 S/m, 30.68 ± 0.85 mg/100 mL, 4.64 ± 0.0 mg/100 mL, 83.69 ± 0.18%, and 0.130 ± 0.0%). Optimized sapodilla juice was lower in sedimentation index (0.73 ± 0.11%), turbidity (13.73 ± 1.10 NTU), ash (0.57 ± 0.031%), and β-carotene (0.173 ± 0.008 μg/100 mL) as compared to control sample (1.07 ± 0.02%, 79 ± 0.75 NTU, 0.65 ± 0.031%, and 0.306 ± 0.007 μg/100 mL). The flow behavior index (n) was closer to 1 in both juice samples, which indicated Newtonian-like flow behavior. Conclusively, sapodilla juice extraction at optimal condition (0.120% of pectinase concentration) and 42.02°C/167.83 min would be potentiated to the beverage industry. The use of pectinase might reduce membrane fouling and facilitates processing operation efficiently.

Exploring Relationships between Aroma, Tasty Components Properties, and Marketing Price of Chinese Cabernet Sauvignon Using Gas Chromatography Mass Spectrum and High-Performance Liquid Chromatography

The purpose of this paper was to find the relationship between aroma and tasty component properties and marketing price of Chinese Cabernet Sauvignon red wines. One-way ANOVA was used to compare differences ( p < 0.05 ) between concentrations of phenolic compounds, organic acids, monosaccharides and total acidity, total polyphenols, total sugars, and total reducing sugars in various Chinese Cabernet Sauvignon red wines with different marketing prices. Principal component analysis revealed that the presence of higher amount of alcohol appears to be the characteristic feature for the wine samples, which have a lower marketing price, and the higher level of esters and acids were the features of the wine samples with a higher marketing price. Moreover, samples in marketing price area 39 to 79 RMB and samples in marketing price area 188 to 258 RMB can be totally clustered into their own marketing price area by volatile compounds with OAV > 1. Acetic acid, succinic acid, and glucose made a great contribution to most of the wine samples in the marketing price area ranging from 39 to 79 RMB, and glycerol, fructose, and malic acid were the features of most wine samples in the marketing price area ranging from 188 to 258 RMB. Concentrations of total acidity, total polyphenols, total sugars, total reducing sugars, and alcohol content seemed to have no significant distinguishing ( p < 0.05 ) ability on different samples belonging to different marketing price areas.

Investigation of the Substituent Effects of the Azide Functional Group Using the Gas-Phase Acidities of 3- and 4-Azidophenols

The electronic effect of the azide functional group on an aromatic system has been investigated using Hammett-Taft parameters obtained from the effect of azide substitution on the gas-phase acidity of phenol. Gas-phase acidities of 3- and 4-azidophenol have been measured using mass spectrometry and the kinetic method and found to be 340.8 ± 2.2 and 340.3 ± 2.0 kcal/mol, respectively. The relative electronic effects of the azide substituent on an aromatic system have been measured using Hammett-Taft parameters. The σF and σR values are determined to be 0.38 and 0.02, respectively, consistent with predictions based on electronic structure calculations. The values of σF and σR demonstrate that azide acts as an inductively withdrawing group but has negligible resonance contribution on the phenol. In contrast, acidity values calculated for azide-substituted benzoic acids give values of σF = 0.69 and σR = -0.39, indicating that the azide is a strong π donor, comparable to that of a hydroxyl group. The difference is explained as being the result of "chimeric", or, alternatively, "chameleonic" electronic behavior of the azide, similar to that observed previously for the N-oxide moiety, which can be more or less resonance donating in response to the environment.

(R)‐BINOL‐6,6’‐bistriflone: Shortened Synthesis, Characterization, and Enantioselective Catalytic Applications

AbstractThe title compound, characterized by X‐ray crystallography, was accessed in 4 steps with 92 % ee. and 25 % yield from an O‐protected (R)‐BINOL precursor. This revised synthetic route relied on a chlorosulfonylation reaction, as a shortcut to a previously developed sequence requiring the use of toxic SO2 gas and bromine. The strongly electron‐impoverished (R)‐6,6′‐Tf2‐BINOL proved an effective ligand in metal‐catalyzed enantioselective transformations such as a Zr‐based Mannich‐type reaction. The catalytic species was characterized by X‐ray crystallography as a unique tetrameric metal cluster. The 6,6′‐bistriflone groups also allowed to exalt the H‐bond donor capacity of the BINOL moiety, as illustrated in an organocatalyzed Morita‐Baylis‐Hillman transformation. Theoretical study indicated that the 6,6′‐bistriflone groups induce a drop of the phenol acidity of 5 pKa units in DMSO. Overall, this work simplified the access, completed the characterization, and confirmed the potential of (R)‐6,6′‐Tf2‐BINOL as a promising platform to further elaborate activated chiral metal ligands or organocatalysts.

ULTRASONİK VE ELEKTRİKSEL ÖN İŞLEMLERİN KİVİ DİLİMLERİNİN KURUMA VE KALİTE ÖZELLİKLERİNE ETKİSİ

In this study, the drying characteristics and quality properties of electrical (ET) and ultrasound (US) pre-treated kiwi fruit slices were investigated. Electrical and ultrasound pretreatments were carried out on the parameters of 100 V- 40 sec. and 35 kHz-30 min respectively. After the pretreatments, the kiwi fruit slices were dehydrated using a convective dryer at 50°C and 1.5 m/s air flow rate. The effects of these pretreatments on the drying rate and quality properties (the total phenolic content, vitamin C, pectin contents, rehydration rate, acidity, and color values) were evaluated. Consequently, the US and ET pretreatments provided an increase in the drying rate by 18.34% and 21.65% respectively. The combination of pretreatments (ET+US) increased the drying rate by 35.70%. The ET pretreatment produced minimum changes in the samples' pectin content and color values, and the US application increased the vitamin C, rehydration capacity, and acidity.

Antimicrobial effects of fruit sauces on some pathogenic bacteria in vitro and on chicken breast meat

The use of natural food additives is currently a rising trend. In the present study, the aim was to determine the antimicrobial effects of plum, pomegranate, Seville orange and sumac sauces on E. coli O157:H7,E. coli type I,Listeriamonocytogenes, Listeria ivanovii, Salmonella Typhimurium and Staphylococcus aureus. Different concentrations (1%, 10%, 100%, v/v) of the sauces were tested on the studied bacteria in vitro using the agar diffusion and minimal inhibition concentration (MIC) methods. The results showed that the sumac sauce had the highest antimicrobial activity. The Seville orange, plum and pomegranate sauces also exerted antimicrobial activity in descending order. The antimicrobial activity of the fruit sauces was more effective at a concentration of 100% than at 10% and 1%, v/v. The most inhibitory effect was recorded for sumac sauce at a concentration of 100% (v/v) on L.monocytogenesand E. coli O157:H7. The findings of the MIC method aligned with the agar diffusion method. In addition, the in situ(food method) antimicrobial effect of the sauces on the indigenous microflora of chicken breast samples sold in stores was determined. Chicken samples hosting aerobic mesophilic bacteria, coliforms and E. coli were treated for two hours at 4 °C with plum, pomegranate, Seville orange and sumac sauces and were then monitored. The findings revealed that the Seville orange and sumac sauces were the most effective in reducing the indigenous microbial growth on the chicken samples. The plum sauce showed higher antimicrobial activity than pomegranate sauce. The phenolic content and acidity of the samples significantly (P< 0.05) affected the antimicrobial activity both in vitro (agar diffusion and MIC) and in situ (chilled chicken breast). In conclusion, the sumac and Seville orange sauces were found to be the most promising natural antibacterial agents, and their use could be recommended, for example, in catering services to reduce the risk of foodborne illness.

Modified Atmosphere Packaging and Heat Treatment for Maintaining the Quality of Fresh-cut Pineapple (Ananas comosus)

The research aimed to determine the effect of modified atmosphere packaging (MAP) and heat treatment to maintain the quality and prolong the shelf life of fresh-cut pineapples (Ananas comosus). The fresh-cut pineapples of cultivar “Queen” and “Cayenne” were treated with four treatments, namely (P1) MAP with 70% argon gas (Ar) and heat treatment at 40oC for 5 min, (P2) heat treatment at 40° for 5 min, (P3) MAP with 70% Ar, (P4) Control. All treatments were stored in a cooler at 10oC and measurements of physical (firmness) and chemical (total phenol, total sugar and titratable acidity) were performed on 0, 2, 4, 6, 8 and 10 days of storage. Each treatment was replicated three times and the results were analyzed using Completely Randomized Design (CRD). The results showed that the application of MAP and heat treatment either combined or individually was able to maintain the quality and prolong the shelf life of fresh-cut pineapple in both cultivars.

Oligo(ethylene glycol) (OEG) functionalized 2-(2′-Hydroxy benzofuranyl) benzoxazole (HBBO) derivatives: Synthesis, photophysical properties and biomolecules binding studies

Two molecular fluorophores based on a 2-(2′-Hydroxybenzofuranyl) benzoxazole (HBBO) scaffold and presenting an Excited-State Intramolecular Proton Transfer (ESIPT) process are reported herein. These dyes incorporate strongly electrodonating aromatic amino groups on the benzofuranyl side, enabling the appearance of a dual fluorescence emission corresponding to the radiative decay of the excited enol (E*) and keto (K*) tautomers at high and low energy respectively. It was previously demonstrated that dual E*/K* emission could originate from a beneficial decrease of phenolic acidity upon absorption of light leading to a thermodynamic stabilization of the first excited-state. The innovation within these dyes lies in the double functionalization of the aniline moiety with 2-(2-methoxyethoxy)ethyl units which allowed a better solubilization in protic solvents, as compared to their butyl analogs while keeping strong electrodonating capacity. Their intrinsic amphiphilic character leads to a good vectorization in a wide range of solvents from toluene to PBS buffer. The investigation of the photophysical properties of these dyes in solution showed a clear dual emission in apolar solvents with the E* band gradually red-shifting along with the dipole moment of the solvent. Dual emission is also observed in the solid-state when these dyes are doped as 1% wt in PMMA or PS films. Finally, the interactions of one dye with calf-thymus (ct)-DNA and Bovine Serum Albumin (BSA) have been explored and reveal pronounced modifications of the UV–Vis profile of the dye. Additionally, a gradual hypsofluorochromic shift and narrowing of the K* band along with the appearance of the E* fluorescence band upon addition of ct-DNA or BSA is also observed, presumably evidencing an intercalation mode of binding.

Photochemical O-H Functionalization of Aryldiazoacetates with Phenols via Proton Transfer.

In this work, we report a thorough investigation of the reaction of phenols with aryldiazoacetates. Mechanistic studies using different spectroscopic methods and theoretical calculations suggest a hydrogen bond between phenol and aryldiazoacetates, which can be modulated by the phenol acidity. The pKA of phenol and therefore the hydrogen bond plays an important role in a subsequent photoinduced proton transfer reaction to give the formal O-H functionalization product of phenols.

Source-dependent compositional changes in coconut flavoured liquid smoke and its application in traditional Indian smoked fishery products

ABSTRACT Smoking is an age-old food preservation method. Intense smoking results in deposition of carcinogenic polycyclic aromatic hydrocarbons (PAH) in food. Replacing traditional smoking practices with application of liquid smoke or smoke flavouring is proven to reduce the PAH content without adversely affecting flavour of the products. This study explores source-dependant variations in composition of a coconut-flavoured liquid smoke. Liquid smoke produced from coconut husk (CH), coconut fibre (CF) and coconut fibre powder (CP) was analysed for total phenolic content, total carbonyls, titratable acidity, pH and PAH content. Resultant liquid smokes were also compared a commercial liquid smoke (CL) for composition. Total phenolic content in the liquid smokes ranged from 1518 ± 184 (CH), 1037 ± 110 (CF), 834 ± 48.23(CP) and 20047 ± 193 mg L−1 (CL). Commercial liquid smoke showed highest total PAH content 215 ± 15.45 ng ml−1 followed by 8.23 ± 1.47 (CP), 7.22 ± 1.44 (CF) and 0.64 ± 0.13 ng m−1 (CH). Further, process parameters for producing ‘masmin’ – a popular traditional smoked and dried ready-to-eat product – by replacing traditional smoking practices with liquid smoking were standardised using Response Surface Methodology. Spraying cooked skipjack tuna (Katsuwonus pelamis) loins with coconut husk liquid smoke containing 4% salt for 155 min at flow rate of 3 L hr−1 and chamber temperature of 60°C was found to give the product a matching flavour with traditional masmin.

Acidity Constants of Lignin Model Compounds in the Electronically Excited State in Water–N,N-Dimethylformamide Mixtures

The acidity constants of a number of guaiacyl phenols simulating structural fragments of natural lignins in the electronically excited state in water–N,N-dimethylformamide mixtures are determined by fluorescence spectroscopy using the Forster cycle. The differentiating effect of an aprotic solvent on the acidity of phenols is shown. It is found that the pKa values in the excited state are associated with the properties of para-substituents with respect to the phenolic hydroxyl group. The highest capacity for acid ionization during photoexcitation is exhibited by compounds containing an electron-withdrawing carbonyl group.

Influencia del método de deshidratación sobre la calidad de snacks de zapallito redondo [Cucurbita maxima var. Zapallito (Carr.) Millán)

El creciente interés por los snacks de vegetales no amiláceos, preparados sin fritura se explica por su menordensidad calórica, respecto a la papa deshidratada y frita. Los métodos convencionales de secado a altatemperatura en ciertos casos pueden provocar pérdidas de componentes bioactivos. Es por ello que existeinterés en la búsqueda de nuevos métodos de procesamiento que reduzcan el desperdicio de estos productos. En este trabajo, se evaluó la calidad (antioxidantes fenólicos, carotenoides, azúcares, acidez, color, aceptabilidad sensorial e higroscopicidad) de snacks de zapallito redondo obtenidos por dos métodos diferentes: 1) secado con aire caliente (SAC) o 2) por un método combinado de deshidratación osmótica (DO) con NaCl seguido de una etapa de secado por aire caliente (DO+SAC). Dependiendo de la concentración de NaCl empleada, la etapa de DO permitió reducir la humedad inicial del vegetal en 15-30%. La incorporación de un pre-tratamiento de DO antes del secado por aire caliente no afectó la acidez, azúcares ni contenido de compuestos fenólicos del producto final. Los snacks obtenidos por el método combinado DO+SAC, mostraron mejor color y aceptabilidad sensorial, mayor nivel de carotenoides extraíbles y menor higroscopicidad que los producidos por SAC. Los resultados del presente trabajo muestran que los tratamientos combinados de DO y aire caliente, resultan en snacks de zapallito redondo con mejores propiedades físicas (color, higroscopicidad), nutricionales (carotenoides) y sensoriales (aceptabilidad) que aquellos obtenidos sólo por secado convencional con aire caliente.

Copper(II) Coordination and Translocation in Luteolin and Effect on Radical Scavenging.

Luteolin differs as a radical scavenger dramatically from apigenin in response to Cu(II) coordination despite a minor structural difference. Coordination of Cu(II) increases the radical scavenging efficiency of luteolin, especially at low pH, while decreases the efficiency of apigenin at both low and higher pH as studied by ABTS•+ radical scavenging. Luteolin forms a 1:1 complex with Cu(II) binding to 4-carbonyl and 5-phenol for pH <6 and to 3',4'-catechol for pH >6. Apigenin forms a 1:2 complex independent of pH coordinated to 4-carbonyl and 5-hydroxylyl. Cu(II) coordinated to luteolin, as studied by pH jump stopped-flow, translocates with rate constants of 11.1 ± 0.3 s-1 from 4,5 to 3',4' sites and 1.0 ± 0.1 s-1 from 3',4' to 4,5 sites independent of Cu(II) concentration, pointing toward the dissociation of Cu(II) from an intermediate with two Cu(II) coordination as rate determining. 3',4'-Catechol is suggested to be a switch for Cu(II) translocation with deprotonation initiating 4,5 to 3',4' translocation and protonation initiating 3',4' to 4,5 translocation. For dicoordinated apigenin, the coordination symmetry balances an electron withdrawal effect of Cu(II) resulting in a decrease of phenol acidity and less radical scavenging efficiency compared to parent apigenin. Compared to that of parent luteolin, the radical scavenging rate of both 4,5 and 3',4' Cu(II)-coordinated luteolin is enhanced through increased phenol acidity by electron withdrawal by Cu(II), as confirmed by density functional theory (DFT) calculations. Coordination and translocation of Cu(II) accordingly increases the antioxidant activity of luteolin at pH approaching the physiological level and is discovered as a novel class of natural molecular machinery derived from plant polyphenols, which seems to be of importance for protection against oxidative stress.

Correlation among Some Biochemical Compounds in Fruit, Leaf, and Shoot Bark of Pomegranate Trees for Breeding Programs

ABSTRACT This study was designed to compare biochemical characteristics in fruit, leaf and shoot bark among some Iranian pomegranate genotypes to determine for any probable correlation between different parts. Twenty genotypes were used in this experiment and biochemical characteristics such as vitamin C, anthocyanin, total phenolic content (TPC), titratable acidity (TA) and total soluble carbohydrate (TSC) were evaluated in leaf, arils, fruit peel, and shoot bark separately. Results of correlation analysis showed that there was significant correlation among anthocyanin, vitamin C, and TPC of arils with anthocyanin (r = 0.93), vitamin C (r = 0.90), and TPC (r = 0.95) of the leaf, respectively. Also, a positive correlation was observed between TA, vitamin C, anthocyanin, and TPC of arils with TSC of the shoot bark. Based on obtained results from this study, biochemical traits of the leaf such as anthocyanin, vitamin C and TPC can be used as a biochemical marker to determine superior genotypes in juvenile phase of plants.

Organic Compounds Determined at Different Levels of Ripening of the Pineapple (Ananas comosus L. Merr.) Cv Cayenne in Two Cultivation Systems under Subtropical Conditions

ABSTRACT This article studies the organic compounds of pineapple fruit, during ripening in two cultivation systems (greenhouse and field), in a subtropical region. Total reducing sugars, organic acids, total phenolic content and antioxidant activity were measured during fruit growth (60, 90, 120 and 150 days after full bloom). In addition, leaf ¨D¨ was used for determination of chlorophyll content, pH and malic acid in three moments of the day during the same cycle. The concentrations of reducing sugars, total phenolic content and acidity increased at the end of the growth of the pineapple fruits in both cultivation systems. Field conditions were more favorable for the accumulation of reducing sugars and total phenolic content in fruits.

Punicalagin Content and Antifungal Activity of Different Pomegranate (Punica ganatum L.) Genotypes

This study investigated the antifungal activity of a number of pomegranate genotypes. Since the main compound of pomegranate extract is punicalagin, an important substance involved in antifungal and antimicrobial activity, we analyzed the contents of punicalagin (α and β) in 21 different pomegranate genotypes. Ellagic acid content, total phenolic content, acidity and pH were also determined. This work allowed us to determine which genotypes of pomegranate can be used to obtain extracts with the highest content of punicalagin, with the goal of developing a green alternative to synthetic pesticides. To improve the extraction system from pomegranate peel fruits, several different solvents were tested. All the pomegranate genotypes tested showed antifungal activity; some genotypes were able to almost completely inhibit the fungus, while others had very low inhibitory activity. Research results also showed that the use of water as a solvent for extraction is very effective, especially when it is combined with ethanol. This is very important for the practical use of the extracts since water is economical and environmentally friendly. The research showed that among the genotypes there is also great variability regarding the chemical parameters. Genotypes with a high phenolic and punicalagin content were significantly correlated with antifungal activity. All the other chemical parameters (pH, titratable acidity and ellagic acid content) were not correlated with antifungal activity. The results obtained indicate that the fruits of some pomegranate genotypes could be used to obtain extracts very rich in punicalagins and that these substances could be used as an alternative to synthetic products to control plant disease and improve the quality of the plant products, avoiding the impact of synthetic chemicals on the environment.