Pungent Sensation Research Articles

Optimization of sensory properties of ultrasound-treated strawberry vinegar

Vinegar is renowned for its benefits to human health due to the presence of antioxidants and bioactive components. Firstly, this study optimized the production conditions of ultrasound-treated strawberry vinegar (UT-SV), known for its high consumer appeal. The sensory properties of UT-SV were optimized by response surface methodology (RSM) to create the most appreciated strawberry vinegar. Secondly, various quality parameters of conventional strawberry vinegar (C-SV), UT-SV, and thermally pasteurized strawberry vinegar (P-SV) samples were compared. RSM was employed to craft the best strawberry vinegar based on consumers ratings of UT-SV. Sensory characteristics, bioactive values, phenolic contents, and organic acid contents of C-SV, UT-SV, and P-SV samples were assessed. Through optimization, the ultrasound parameters of the independent variables were determined as 5.3 min and 65.5 % amplitude. The RSM modeling levels exhibited high agreement with pungent sensation at 98.06 %, aromatic intensity at 98.98 %, gustatory impression at 99.17 %, and general appreciation at 99.26 %, respectively. Bioactive components in UT-SV samples increased after ultrasound treatment compared to C-SV and P-SV samples. Additionally, the amount of malic acid, lactic acid, and oxalic acid increased after ultrasound treatment compared to C-SV samples. Ultimately, UT-SV with high organoleptic properties was achieved. The ultrasound treatment positively impacted the bioactive values, phenolic and organic acid content, leading to the development of a new and healthy product.

DESCRIBING THE GINGER PLANT AND ITS EFFECTIVE INGREDIENTS ALONG WITH ITS THERAPEUTIC PROPERTIES IN VARIOUS COMPLICATIONS

Abstract Plants are one of the important and valuable sources in the preparation of medicines, both in traditional medicine and in the form of pure products. Ginger is obtained from a yellow plant with purple veins with the scientific name Zingiber officinale. Although ginger is usually referred to as the root of the plant, actually the part used is the swollen underground stem called the rhizome. The aroma and flavor of ginger are due to the presence of two types of volatile oils and non-volatile pungent compounds. The biologically active components of ginger are classified in the second category, among the most important molecules in this category, are gingerol and shogaol, which cause a pungent sensation in the mouth. Most properties of ginger are attributed to non-volatile components with a spicy taste. The properties of these substances can be reduced blood sugar, weight loss, increased blood insulin, effect on blood coagulation, effect on blood pressure, reduction of complications of gastrointestinal diseases, reduction of nausea caused by pregnancy, or the use of chemotherapy drugs, the protective effect of the tissue against chemical and radio damage with anti-inflammatory properties, antioxidant properties, antibacterial and antifungal properties, especially Candida albicans, anti-cancer properties through antioxidant and anti-inflammatory properties. This study aimed to describe the ginger plant and its active ingredients and some features including anti-inflammatory effects, anti-oxidative effects, anti-cancer effects, and so on.

Antioxidant properties of capsaicin analogues: a DFT study

Capsaicin is the one of the primary components of fruits of gender Capsicum and is responsible of the pungent sensation known “spiciness”. In the recent years this compound has attracted special attention thanks to their beneficial biological effects, such as their antioxidant, antiobesity and antidiabetic activity, among others. In the present studio. In the present studio, thirteen capsaicin analogues with functional groups -SH, -NH2, -OCH3 and -F in the aromatic ring, have been proposed and studies trough DFT methodologies. The reactivity indexes and primary antioxidant activity were obtained. According to the obtained results, most of the analogues with the amine group (-NH2) shown better ability to donate and accept electrons, which translates into a better antioxidant activity

Pepper variome reveals the history and key loci associated with fruit domestication and diversification

Pepper (Capsicum spp.) is an important vegetable crop that provides a unique pungent sensation when eaten. Through construction of a pepper variome map, we examined the main groups that emerged during domestication and breeding of C. annuum, their relationships and temporal succession, and the molecular events underlying the main transitions. The results showed that the initial differentiation in fruit shape and pungency, increase in fruit weight, and transition from erect to pendent fruits, as well as the recent appearance of large, blocky, sweet fruits (bell peppers), were accompanied by strong selection/fixation of key alleles and introgressions in two large genomic regions. Furthermore, we identified Up, which encodes a BIG GRAIN protein involved in auxin transport, as a key domestication gene that controls erect vs pendent fruit orientation. The up mutation gained increased expression especially in the fruit pedicel through a 579-bp sequence deletion in its 5′ upstream region, resulting in the phenotype of pendent fruit. The function of Up was confirmed by virus-induced gene silencing. Taken together, these findings constitute a cornerstone for understanding the domestication and differentiation of a key horticultural crop.

Antifungal compounds of Chinese prickly ash against drug-resistant Candida albicans.

The leaf of Chinese prickly ash, a unique spice having typical pungent sensation, is a popular food in Southwest China with antipruritic, insecticidal and fungicidal functions, but its bioactive constituents of fungistatic capacity remain unknown. In present investigation, twenty-nine compounds were isolated from leaf of Chinese prickly ash, and their antifungal bioactivity against drug-resistant Candida albicans were evaluated in vitro and in vivo. As a result, three compounds 3, 10, 29 showed antifungal bioactivity by damage of the fungal biofilm, and they might recover sensitive of drug resistant C. albicans to Fluconazole. Then Chinese prickly ash leaf was proved to be a functional food against fungus for the first time in experiment.

A novel strategy based on dynamic surface-enhanced Raman scattering spectroscopy (D-SERS) for the discrimination and quantification of hydroxyl-sanshools in the pericarps of genus Zanthoxylum

The pericarps of genus Zanthoxylum (PZ) are used as a condiment in Chinese cuisine, while hydroxyl-sanshools (HS) are primary components evoking specific pungent sensations. This study developed a novel method for distinguishing the PZ species and detecting HS in PZ by combining dynamic surface-enhanced Raman scattering spectroscopy (D-SERS) with a homogeneous gold nanorods (AuNRs) substrate. Furthermore, principal component analysis (PCA) separated the D-SERS spectra data of 26 PZ samples into two groups. The concentration of hydroxyl-α-sanshool (α-SOH) in a range of 0.1–12 mg mL−1 displayed an excellent linear relation with the peak intensity, while the detection limit at 0.03 mg mL−1 the requirements for detecting HS in currently known PZ. Compared to high-performance liquid chromatography (HPLC) analysis, the established method demonstrated excellent accuracy in PZ samples. This study provided an alternative method based on D-SERS coupled with AuNRs for rapidly and accurately determinating HS in PZ samples.

Quality Evaluation of Shrimp (Parapenaeus longirostris) Treated with Phenolic Extract from Olive Vegetation Water during Shelf-Life, before and after Cooking.

The focus of this study was to assess the quality traits and sensory profile of cooked rose shrimps (Parapenaeus longirostris) treated with a phenolic extract, derived from olive vegetation water (PEOVW). To achieve the aim, four different groups of shrimps were analysed, specifically the control (CTRL) group, where the shrimps were soaked in tap water; sulphites (S) group with shrimps soaked in 0.5% sodium metabisulfite tap water solution, phenolic extract (PE) group where a tap water solution containing 2 g/L of phenols was used; and PE+S group where the shrimps were dipped in 0.25% sodium metabisulfite tap water solution containing 1 g/L of phenols. The groups were then stored at 2 °C and analysed on the day of packaging (D0), after 3 (D3), 6 (D6), and 8 (D8) days. On each group, microbiological parameters such as Enterobacteriaceae, mesophilic and psychrotrophic bacteria, and colorimetric indices were investigated on six (n = 6) shrimps before cooking, while the evolution of the phenolic content, antioxidant activity, and sensory analysis during the storage period were evaluated on cooked shrimps. Regarding colour coordinates, there were no noteworthy variations overtime nor between groups, while it is important to note that the microbiological results for the PE group showed at each time interval and for all the considered parameters, significantly lower values than the other groups (p < 0.05). This result is very interesting when considered further in correlation with the sensory analysis, where shrimps mainly in PE and secondarily in PE+S groups were shown to retain the freshness characteristics better than the other groups (α = 0.01), without giving the shrimps any particularly bitter and pungent sensations typical of the olive phenolic compounds. In conclusion, the results obtained in this study give PEOVW the potential to be valorised in the food sector and, above all, it could represent a sustainable solution to reduce the use of synthetic additives.

The influence of NaCl on the dynamic perception of the pungency sensation elicited by Sichuan pepper oleoresins

A cross-modal interaction may exist between the perception of saltiness and the pungency elicited by Sichuan pepper oleoresin (Spo). Thirty-one hypersensitive panelists were selected to participate in this study. Spo solutions dissolved in different NaCl concentrations, ranging from 1.25 g/L to 167.9 g/L, were used as the test samples. The rated difference from control, the generalized labeled magnitude scale (gLMS), and the time-intensity (TI) method were used to determine the detection threshold (DT), the recognition threshold (RT), the intensity, and the dynamic perception of pungent sensation. The results revealed that the pungency thresholds increased significantly (p < 0.01) in the solution with a high NaCl (167.9 g/L) concentration. Furthermore, high NaCl solutions suppressed the pungency intensity at all Spo concentrations except for 0.02 g Spo/L in water (p < 0.05). The TI and principal component analysis (PCA) results showed that an increase in the Spo concentration prolonged the duration of the pungency sensation. However, the maximum intensity, the time to reach maximum intensity, the decay time of perception, and the end time of perception of the Spo solutions ranging from 2.13 g/L to 4.69 g/L were significantly reduced at medium (42.95 g/L) and high NaCl concentrations. Since the salty and pungency sensations exhibited by NaCl and Spo are common flavor combinations in food products and dishes, studying the influence of saltiness on the dynamic perception of pungent sensation not only aids the development of oral cleaners during pungency evaluation but also presents significant theoretical and practical value in creating pungent food and cuisine based on consumer preferences.

A comparative overview on chili pepper (capsicum genus) and sichuan pepper (zanthoxylum genus): From pungent spices to pharma-foods

Both Chili pepper (CP) and Sichuan pepper (SP) have long been used for culinary purposes throughout Asia. It is well known CP and SP are well accompanied in Sichuan Cuisine, producing a typical pungent sensation. In recent decades, increasing evidences suggest a series of health benefits and pharmacological effects are associated to the two peppers. Now, a systematic comparison of structural and bioactivities diversity of bioactive ingredients from edible parts of two peppers are necessary to address their future application. Bioactive composition, organoleptic property as well as pharmacological activity in cellular, animal, and human subjects are compared between SP (pericarps and leaves) and CP (fruits). Both SP and CP are rich in alklyamides, polyphenols, and odorants but their structures are greatly variable. Carotenoids are primarily identified in CP but rather in SP, whereas coumarins are the specific ingredients in SP as compared with CP. Pungent sensations evoked by capsainoids and sanshools are obvious distinct, which is attributed to different mechanisms of interaction with membrane ion channels. Due to these bioactives, especially for capsaicin and hydroxyl-α-sanshool, extracts and purified compounds of CP and SP presented attenuation effects against pain, obesity and hyperlipidemia, diabetes, atherosclerosis, gastrointestinal disorder, tumors, and neurodegenerative diseases even though large-scale and well-designed clinical trials are highly needed. However, more approaches should be conducted to overcome side effects of capsaicin during clinical application. Also, the pharmacological interaction among bioactives in two peppers should be further verified in physiological condition. • The two peppers are rich in alklyamides, polyphenols, and odorants. • Carotenoids are primarily identified in chili pepper but rather in Sichuan pepper. • Coumarins are specific bioactives in Sichuan pepper as compared with chili pepper. • Pungent sensations evoked by capsainoids and sanshools are obviously distinct. • Pharmacological interaction among bioactives in two peppers should be verified.

The effect of the pungent sensation elicited by Sichuan pepper oleoresin on the sensory perception of saltiness throughout younger and older age groups

Excessive salt in the diet can pose significant health risks and, therefore, the reduction of salt derived from food is an important issue relating to human nutrition and health. Furthermore, the perception of saltiness will be different among people when considering their innate sensitivity, gender, age, psychological traits and dietary habits. In this study, 31 younger participants and 29 older participants were used as research subjects. A web-based questionnaire survey was used to collect information regarding of socio-demographics, consumption frequency and liking for salty and pungent food, as well as personality traits throughout the younger and the older participants. In addition, the 6-n-propylthiouracil (PROP) ratings were tested by the generalized Labeled Magnitude Scale (gLMS) in the laboratory conditions. The rated difference from control method was used to test the sensitivity differences in the saltiness of NaCl and the pungent sensation elicited by Sichuan pepper oleoresin between the younger and older groups. The results showed that the thresholds were significantly lower in the younger group than in the older group, except for the detection threshold of saltiness. Furthermore, the recognition threshold of saltiness decreased in the presence of the sub-threshold pungency solution, while, the salty intensity was enhanced in both the younger and older groups when exposed to the slightly pungent solution (0.106 g Sichuan pepper oleoresin/L water solutions) compared to the control (spring water). For the younger group, the enhancement percentage of the salty intensity was between 9.3% and 12.5%, while, at the concentration of 4.05 g/L, the salty-enhancement percentage increased by 6.4% in the older group. In addition, the reduction percentage of NaCl reached a level of up to 34.4% in the younger group and was 4.4% in the older group. The Partial Least Squares Regression (PLSR) results indicated that the percentage change in salty intensity increased when the detection threshold of saltiness, the sensation seeking ratings, and PROP ratings increased. On the contrary, the change decreased when the age, life satisfaction ratings, detection threshold of pungency, and consumption frequency of salty food increased. These findings not only provide new information for the flavor design of salt-reduced food and dishes, but also be valuable to public health as well as economic benefits.

Development of differential pulse voltammetric method for rapid quantification of total hydroxyl-sanshools in Sichuan Pepper

Hydroxyl-sanshools (HS) are primary components evoking specific pungent sensations of Sichuan Pepper (pericarp of Zanthoxylum bungeanum, PZB) which is widely used as a food condiment in Chinese cuisine. In present work, voltammetric characterisation of HS was investigated, and a protocol described an efficient electrochemical method (DPV) for detecting the content of total HS analyte quantitatively in PZB samples was first proposed. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed for the electrochemical reversibility of representative HS compounds, and the effect of the supporting electrolyte on the voltammetric signal of hydroxyl-α-sanshool (α-SOH) was investigated by DPV. Under the optimal operating conditions, DPV was used to quantify the concentration of α-SOH with satisfactory linearity (0.25–78.9 mg L−1), sensitivity (LOD = 0.03 mg L−1), repeatability (RSD = 2.1%). Furthermore, this DPV method via standard addition method was successfully used for the quantification of the total content of HS in PZB models in the linear range of 1.87 and 80.93 mg g−1. The established DPV method exhibited high measurement accuracy in actual PZB samples as compared with HPLC-MSn analysis and demonstrated satisfied recoveries (94.56–108.02%). Taken together, it was evidenced that this protocol was a hopeful alternative way to conveniently quantify total HS contents in PZB samples.

Biochemistry and molecular biology of capsaicinoid biosynthesis: recent advances and perspectives.

The most widely known characteristic of chili pepper fruits is their capacity to produce capsaicinoids, which are responsible for the pungent sensation. The capsaicinoids have several uses in different areas, such as the pharmaceutical, cosmetic and agronomic industries, among others. They are synthesized by the condensation of vanillylamine (derived from phenylalanine) with a branched-chain fatty acid (from valine or leucine precursors), and they generally accumulate in the placental tissue of the chili pepper fruits. The pungency grade depends on the genotype of the plant but is also affected by external stimuli. In recent years, new structural and regulatory genes have been hypothesized to participate in the capsaicinoid biosynthetic pathway. Moreover, the role of some of these genes has been investigated. Substantial progress has been made in discerning the molecular biology of this pathway; however, many questions remain unsolved. We previously reviewed some aspects of the biochemistry and molecular biology of capsaicinoid biosynthesis (Aza-González et al. Plant Cell Rep 30:695-706. Aza-González et al., Plant Cell Rep 30:695-706, 2011), and in this review, we describe advances made by different researchers since our previous review, including the contribution of omics to the knowledge of this pathway.

Development of yuja (Citrus junos) beverage based on antioxidant properties and sensory attributes using response surface methodology.

This study aimed to develop a new type of Citrus junos beverage (known as yuja in Korean and yuzu in Japanese) based on a traditional drink preparation method (Galsu). Processing conditions (yuja extract, sugar, and soybean milk) were optimized using response surface methodology (RSM) to develop the beverage. The polynomial models developed by RSM were based on physicochemical characteristics and sensory attributes. Sugar, vitamin C, and total phenolic compound contents, DPPH free radical scavenging activity, sweet odor, yuja flavor, sweet taste, and pungent sensation were used as indices of positive product quality. Beany flavor, astringent taste, beany aftertaste, and astringent aftertaste, were used as indices of negative product quality. Sour odor and sour taste, which are the major characteristics of the traditional yuja beverage, were set in a range to optimize the numerical model. The predicted optimum formulation of yuja beverage (Galsu) as a final product was determined to be 28.4% yuja extract, 36.6% sugar, and 35.0% soybean milk.

Individual Variation in PROP Status, Fungiform Papillae Density, and Responsiveness to Taste Stimuli in a Large Population Sample.

Despite considerable research investigating the role of 6-n-propylthiouracil bitterness perception and variation of fungiform papillae density in food perception, this relationship remains controversial as well as the association between the 2 phenotypes. Data from 1119 subjects (38.6% male; 18-60 years) enrolled in the Italian Taste project were analyzed. Responsiveness to the bitterness of 6-n-propylthiouracil was assessed on the general Labeled Magnitude Scale. Fungiform papillae density was determined from manual counting on digital images of the tongue. Solutions of tastes, astringent, and pungent sensations were prepared to be moderate/strong on a general Labeled Magnitude Scale. Four foods had tastants added to produce 4 variations in target sensations from weak to strong (pear juice: citric acid, sourness; chocolate pudding: sucrose, sweetness; bean purée: sodium chloride, saltiness; and tomato juice: capsaicin, pungency). Women gave ratings to 6-n-propylthiouracil and showed fungiform papillae density that was significantly higher than men. Both phenotype markers significantly decreased with age. No significant correlations were found between 6-n-propylthiouracil ratings and fungiform papillae density. Fungiform papillae density variation does not affect perceived intensity of solutions. Responsiveness to 6-n-propylthiouracil positively correlated to perceived intensity of most stimuli in solution. A significant effect of fungiform papillae density on perceived intensity of target sensation in foods was found in a few cases. Responsiveness to 6-n-propylthiouracil positively affected all taste intensities in subjects with low fungiform papillae density whereas there were no significant effects of 6-n-propylthiouracil in those with high fungiform papillae density. These data highlight a complex interplay between 6-n-propylthiouracil status and fungiform papillae density and the need of a critical reconsideration of their role in food perception and acceptability.

Pepper with and without a sting: Brain processing of intranasal trigeminal and olfactory stimuli from the same source

Humans have distinct and overlapping brain regions for the processing of intranasal olfactory or trigeminal stimuli. It may be assumed that trigeminal stimulants and “trigeminal-free” odorous stimuli from the same source are processed differently in the human brain. Using functional magnetic resonance imaging (fMRI), this study investigated the question whether the black pepper (Piper nigrum) derived trigeminal active compound piperine and the trigeminal-free pepper essential oil (pepperEO) are processed in relation to their degree of trigeminal stimulation. Twenty-one young healthy adults underwent a fMRI scan where piperine and pepperEO were delivered orthonasally using an olfactometer. Ratings for intensity, irritability, and pleasantness of each stimulus were obtained at the end of the scanning session. Results showed brain activation of the trigeminal network in response to piperine, and olfactory-related areas in response to pepperEO. PepperEO induced larger activations in the trigeminal network as compared to piperine. This was possibly due to the associative learning for the pungent sensations of pepperEO. In addition, conjunction analyses showed that the secondary somatosensory area, insula, and thalamus were involved in the processing of both piperine and pepperEO. In conclusion, the results strongly suggest that the cerebral representations of trigeminal irritants can be evoked by learned associations.

Oil Characteristics of Four Palestinian Olive Varieties.

Olive oil represents an important source of income for Palestinian farmers in local, national and international markets. Sometimes, olive oil produced in local climatic conditions, does not achieve the International Olive Council (IOC) trade standards so that international markets are precluded. The oil chemical composition and sensory profile of four Palestinian olive varieties (Nabali Baladi, Nabali Mohassan, Souri and K18) were characterized in 2010 throughout an in situ evaluation. Most of the physicchemical characteristics and the fatty acid composition of the varieties met the International Olive Council trade standards (IOC-TS) for extra virgin olive oils. Values of K270 for Nabali Baladi and linolenic acid for Souri slightly exceeded the limit. Eicosanoic acid exceeded the IOC-TS limits in the oils of all considered varieties. Among the sterols, the Δ-7-stigmastenol resulted too high for Nabali Baladi and Souri. Sensory profile for the tested varieties showed a reminiscence of tomato or artichoke and light to medium bitter and pungent sensations. Results represent an important baseline reference for further studies about oil composition and quality of the main Palestinian olive germplasm and provide indication of potential critical points to be controlled in order to ensure the full achievement of IOC-TS and access international markets.

Integrating TRPV1 Receptor Function with Capsaicin Psychophysics

Capsaicin is a naturally occurring vanilloid that causes a hot, pungent sensation in the human oral cavity. This trigeminal stimulus activates TRPV1 receptors and stimulates an influx of cations into sensory cells. TRPV1 receptors function as homotetramers that also respond to heat, proinflammatory substances, lipoxygenase products, resiniferatoxin, endocannabinoids, protons, and peptide toxins. Kinase-mediated phosphorylation of TRPV1 leads to increased sensitivity to both chemical and thermal stimuli. In contrast, desensitization occurs via a calcium-dependent mechanism that results in receptor dephosphorylation. Human psychophysical studies have shown that capsaicin is detected at nanomole amounts and causes desensitization in the oral cavity. Psychophysical studies further indicate that desensitization can be temporarily reversed in the oral cavity if stimulation with capsaicin is resumed at short interstimulus intervals. Pretreatment of lingual epithelium with capsaicin modulates the perception of several primary taste qualities. Also, sweet taste stimuli may decrease the intensity of capsaicin perception in the oral cavity. In addition, capsaicin perception and hedonic responses may be modified by diet. Psychophysical studies with capsaicin are consistent with recent findings that have identified TRPV1 channel modulation by phosphorylation and interactions with membrane inositol phospholipids. Future studies will further clarify the importance of capsaicin and its receptor in human health and nutrition.

Dynamic sensory description of Rioja Alavesa red wines made by different winemaking practices by using Temporal Dominance of Sensations.

Although sensory description of wines in scientific literature is very large, there is an evident lack of studies describing wines from a dynamic approach. The objective of this study was to describe the evolution of the sensations perceived in red wines from Rioja Alavesa by using Temporal Dominance of Sensations (TDS) and also to compare wines made with the two winemaking procedures used in Rioja Alavesa: carbonic maceration (CM) and destemming (DS). Ten sensory attributes were evaluated in eight wines (four CM and four DS wines) in triplicate by a panel of 16 trained assessors. Red/black berry and woody aromas were dominant firstly, whereas heat, astringent, bitter and pungent sensations were dominant later. CM wines showed higher dominance for woody, spicy, pungent and acid sensations and lower dominance for red/black berry aroma and astringency than DS wines. This study is the first to describe Rioja wines from a dynamic approach and it also provides information about the dynamic sensory differences between wines made by CM or by DS. In this sense, this work shows the usefulness of TDS to describe and differentiate wines and to provide additional information to the conventional static descriptive analysis. © 2015 Society of Chemical Industry.

Nonivamide enhances miRNA let-7d expression and decreases adipogenesis PPARγ expression in 3T3-L1 cells.

ABSTRACTRed pepper and its major pungent principle, capsaicin (CAP), have been shown to be effective anti‐obesity agents by reducing energy intake, enhancing energy metabolism, decreasing serum triacylglycerol content, and inhibiting adipogenesis via activation of the transient receptor potential cation channel subfamily V member 1 (TRPV1). However, the binding of CAP to the TRPV1 receptor is also responsible for its pungent sensation, strongly limiting its dietary intake. Here, the effects of a less pungent structural CAP‐analog, nonivamide, on adipogenesis and underlying mechanisms in 3T3‐L1 cells were studied. Nonivamide was found to reduce mean lipid accumulation, a marker of adipogenesis, to a similar extent as CAP, up to 10.4% (P < 0.001). Blockage of the TRPV1 receptor with the specific inhibitor trans‐tert‐butylcyclohexanol revealed that the anti‐adipogenic activity of nonivamide depends, as with CAP, on TRPV1 receptor activation. In addition, in cells treated with nonivamide during adipogenesis, protein levels of the pro‐adipogenic transcription factor peroxisome‐proliferator activated receptor γ (PPARγ) decreased. Results from miRNA microarrays and digital droplet PCR analysis demonstrated an increase in the expression of the miRNA mmu‐let‐7d‐5p, which has been associated with decreased PPARγ levels. J. Cell. Biochem. 116: 1153–1163, 2015. © 2015 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals, Inc.

Modulation of bitterness and pungency in virgin olive oil from unripe “Picual” fruits

Singular virgin olive oils (VOOs) come from unripe olives that show different characteristics affecting processing and oil sensory properties. This work is aimed to study the effect of olive paste malaxation conditions on phenolic fraction and intensities of bitter and pungent sensations in VOOs from unripe “Picual” olives. Experiments were carried out using “Picual” fruits harvested at early dates for three consecutive crop seasons. The malaxation conditions assayed using a factorial design were: time (60 and 90 min), temperature (18, 30, and 40°C) and micronized talc addition (0 and 1%). The main factors affecting oil phenol content were the crop year, malaxation temperatures, and micronized talc addition whereas for malaxation time the effect was not significant. The high olive fruit moistures had a great importance in the oil phenol content and the related sensory parameters. Results indicated as for higher temperature the phenol content and bitterness K225 increased although its effect varied by crop year. Micronized natural talc addition increased the total phenol content and the K225 values. When intensities of pungency and bitterness of the oils were ranked by sensory analysis those obtained at lower temperature were classified as less bitter and pungent. Therefore for early harvesting dates the kneading conditions can be regulated to obtain VOOs with different sensory characteristics and phenol content.Practical applications: Effect of paste malaxation conditions on the virgin olive oil (VOO) bitterness, pungency, and phenolics has been studied for early harvested “Picual” fruit. Bitterness and pungency in “Picual” VOO could be modulated by regulating the malaxation temperature achieving the lower intensities at 18°C without micronized talc addition.Temperature was the olive paste malaxation variable with the highest effect on phenol content in virgin olive oil from early harvested “Picual” fruits. Lower temperature reduced oil phenol content and then, its bitterness and pungent intensities.