Ice Tea Samples Research Articles

Evaluation of the effects of storage time and temperature on the beverages

Beverages are an important part of the food sector their storage is also one of the most critical issues. This study investigated the effects of different storage temperatures and times on physicochemical properties, flavonoid and organic acid contents of soda, sherbet and ice tea produced by adding sour grape concentrate. Changes in the flavan-3-ol content of ice tea were also measured during the storage period. The beverages were stored in three different conditions, cold storage (~4°C), room temperature (~24°C) and controlled storage (20±1°C), for six months and analyzed every two months. Storage temperatures and time affected the total soluble solids and acidities of the beverages (p≤0.05). Tartaric acid decreased during storage, especially during the first two months in sherbets. Ice tea and soda drinks were found more stable than sherbets. The malic acid was found the major organic acid in beverages. Flavonoid content in ice tea was higher than others. The flavonoid concentrations of ice tea stored at 20 and 24°C and of sherbet at 4°C were statistically significant as a function of storage time while these values were not significant for ice tea stored at 4°C and of sherbet at 20 and 24°C (p≤0.05). Concentrations of flavan-3-ols varied with storage conditions. The levels of epicatechin, epigallocatechin and epigallocatechin gallate in ice tea samples decreased between an average of 43.72 and 71.15% at the end of six months of storage. Principal component analysis separated two months storage from other storage periods and perfectly discriminated the studied flavan-3-ols except catechin. Soluble solid and brix-acid ratio also dissociated similarly to flavan-3-ols.

КОНТАМИНАЦИЯ МИКРОПЛАСТИКОМ БУТИЛЛИРОВАННОГО ХОЛОДНОГО ЧАЯ

Due to the increase in plastic production and use around the world in recent years, the amount of microplastics accumulating in the environment has also increased. This dangerous pollutant has penetrated 129 not only into all ecosystems, but even into food and water. This study focused on the presence and prevalence of microplastics in seven iced tea brands. Using FT-IR spectroscopy and microscopic examination, microplastic particles were detected in all iced tea samples studied. It was found that not only water, but also the production process itself and auxiliary raw materials can be sources of microplastic pollution. The chemical components of these microplastic polymers were polyethylene terephthalate, polyethylene and polyamide, and fibers were the predominant particle form. Preliminary data from the study on microplastic contamination in soft drinks may be useful for further assessing the health risks of microplastics.

Sensory test A-Not A rating signal detection: Panel’s sensory learning and stability of decision criteria

Signal detection theory (SDT) sensory discrimination analysis using A-Not A with a two-step rating is an efficient approach to in-house sensory quality management in the food industry. For such sensory analysis using an internal panel, the panels’ ability to use stable decision criteria and provide a consistent response distribution responding to “A” vs “Not A” is critical for guaranteeing the data quality. This study examined the effects of the familiarization procedure (FP) and reference presentation probability (RPP) in the SDT A-Not A rating protocol on the panels’ sensory learning of samples and stability of decision criteria using SDT parameters, recognition d' (d'Rec),criteria location (c), and discrimination d' indices. Three different protocols were compared using ice-tea samples with small differences: Control, 0.25 RPP with repeated reference tasting (FPR); Modified-1, 0.25 RPP with reference categorization (FPC); Modified-2, 0.5 RPP with reference categorization (FPC). An independent sample design with three groups having equal sensitivity was used to identify the differences among the protocols. For each protocol, two sub-groups with similar decision criteria (response bias) were formed according to the results obtained from the pre-test and used for the main-test analysis. SDT analysis results indicated that the Modified-2 protocol with a higher RPP (0.5) induced the most efficient sensory learning of the reference. The protocol improved the subjects’ recognition of the reference and test samples, better differentiating from the reference and stabilizing the decision criterion, resulting in higher discrimination performance (larger d'). The results showed that d'Rec analysis, together with d' analysis using a sensory panel, is a useful tool for monitoring the panel performance and checking for the sensory data quality of the sensory difference tests. In the present paper, a detailed illustration of the A-Not A sensory test procedure and examples of how to apply the SDT indices for different business decision-making is also introduced using the design and results of the present experiment.

Trace elements in ready-to-drink ice tea: Total content, in vitro bioaccessibility and risk assessment

Tea is one of the most consumed non-alcoholic beverages in world and it has been frequently associated to health benefits. Besides its nutrient composition, non-essential trace elements associated with toxic effects may also be present. Ever since food components undergo biotransformation process along gastrointestinal tract after ingestion, it is important to evaluate both total and bioavailable content of trace elements. Therefore, this study aimed to provide comprehensive data concerning the influence of the in vitro digestion on sixteen trace elements present in ready-to-drink ice tea (black, green, mate and white tea). Essential minerals (Co, Cr, Cu, Fe, Mn, Se and Zn) and inorganic contaminants (Al, As, Cd, Li, Ni, Pb, Sb, Sn and Sr) contents were determined by ICP OES after microwave acid digestion. Bioaccessibility evaluation was carried out by simulating the gastric (pepsin) and intestinal juice (pancreatin and bile salts) and bioavailability used Caco-2 cells culture as an intestinal epithelial model. Moreover, tannins were evaluated by UV–VIS spectroscopy. Multivariate analysis allowed classifying ice tea samples in three groups, based on their trace elements profile. Al, Cu, Sr, Mn and Zn bioaccessible fractions corresponded to, approximately, 40–60% of their total content. For Mn, bioaccessibility and bioavailability presented the same pattern (green ice tea > black ice tea > mate ice tea) whilst Sr bioavailability in green tea were 50% higher than in black tea samples.

Using tactile stimuli to enhance sweet perception in iced tea samples

AbstractThe perception and acceptance of food can be influenced by multiple factors, including the sensations generated by the contact with the food surface or its packaging. The aim of the present study was to investigate whether the texture of the cups held when drinking an iced tea sample would have an influence on the perception of its sweetness intensity. Participants tasted four iced tea samples in disposable plastic cups which surface had been modified to elicit different basic tastes, and were asked to rank the drinks depending on their sweetness intensity. Results showed that the texture of the container influenced participants' ranking, and the sweetness perception of the tea could be increased through the cup's surface.Practical ApplicationsResults of the present study are useful mainly for the packaging industry, providing information that verifies the idea that some materials could help increase the acceptance of reformulated products (e.g., beverages with a reduction in the sugar content). In general, the results obtained in the study show a strategy for food reformulation, giving a greater importance on the haptic cues of foods, packaging, and cutlery.

Sweet Liking Status and PROP Taster Status impact emotional response to sweetened beverage

Humans are innately predisposed to enjoy sweetness. However, excessive sugar consumption has been linked to a range of health issues. In order to develop an effective strategy to provide customised products and promote healthy eating, it is important to understand individual variation in sweetness preference. This study investigated how both Sweet Liking Status and PROP Taster Status impact on liking and emotional response to an ice tea product varying in sweetness intensity. One hundred and seventy five consumers were invited to rate liking and sweetness intensity of 5 sucrose solutions and emotional response, liking and sweetness intensity of ice tea samples varying in sweetness concentration (Low, Medium and High), and with sugar type (Sucrose and Sweetener). Cluster analysis followed by validation test within each cluster group has identified 34% High Sweet Likers (HSL), 16% Medium Sweet Likers (MSL), 35% Low Sweet Likers (LSL) and 15% Unclassified group (UN). LSL had an overall heightened sweetness sensitivity than HSL for the sucrose solutions. For ice tea samples, no significant differences on liking and emotional response were observed between the two types of sugar, indicating consumers have a high acceptability when using sweetener as a sugar substitute in beverages. Overall, liking and positive emotions were rated more intensely for the Medium sweetened ice tea, whereas the opposite was found for the Low sweetened ice tea. A significant Sweet Liking Status*Concentration interaction was observed, where for High sweetened ice tea, LSL significantly disliked the sample and associated with lower positive and higher negative emotions, but an opposite trend was observed for HSL. For ideal sweetness, LSL indicated a significant lower ideal sweetness level in ice tea than HSL. Unlike Sweet Liking Status, an overall PROP Taster Status effect on both liking and emotional response was observed, but the effect was found to be independent of sweetness levels. A relative effect of Sweet Liking Status and PROP Taster Status on emotional response was also observed, where the effect of Sweet Liking Status was more pronounced in both pST and pNT group.

Developed of a Green Water Switchable Liquid–Liquid Microextraction Method for Assessment of Selenium in Food and Soft Drink Samples by Using Hydride Generation Atomic Absorption Spectrometry

In the current study, we have developed a green water switchable liquid–liquid microextraction method for separation, preconcentration, and estimation of selenium concentration in the real samples. First time introducing the water switchable liquid–liquid microextraction method to determine the trace level selenium in different food and soft drink samples. Water switchable medium was formed by the reaction of diethylenetriamine base when exposed to uniformed pressure of carbon dioxide. After being exposed to carbon dioxide, water switchable medium reversibly exchanges in two separated aqueous and organic phases. Advantages of carbon dioxide uses are cheap, environmental friendly, non-accumulation, removable, and require the opaque materials for operating container. Water switchable phenomena occurred easily from low polarity to high polarity organic solvent. Experimental variables of the water switchable liquid–liquid microextraction (LLME) method were optimized into its optimum values such as pressure, pH, centrifugation speed, extraction time, and concentration of complexing agent. The certified reference material of Canada Lake Water (TMDA-53.3) and CS-M-3 Mushroom (Boletus edulis) was used for validation of the present water switchable LLME method. Enhancement factor and limit of detection were obtained 85.5 and 0.018 μg kg−1, respectively. Developed green water switchable LLME method was successfully applied for assessment of total selenium in tomato, pumpkin seed, mushroom, garlic, rice, pistachio, chickpea, hazelnut, walnut, apple juice, and ice tea samples.

Solid phase microextraction method using a novel polystyrene oleic acid imidazole polymer in micropipette tip of syringe system for speciation and determination of antimony in environmental and food samples

A simple, rapid and sensitive solid phase microextraction method was used for the speciation of inorganic antimony (Sb) by using a novel synthesized polymeric material in micropipette tip of syringe system. In present methodology, the specie of Sb (III) made hydrophobic complex with diethyl dithiocarbamate (DDTC) at pH 5.5 and subsequently adsorbed on polystyrene oleic acid imidazole polymer (POIP), whereas Sb(V) did not made complex and adsorbed on the polymer, remained in aqueous solutions. The strategy of multivariate was carried out to screen out the different variables and assessed the optimum values of their experimental values for the extraction efficiency of analyte. Then the analyte was sorbed on the polymer in micropipette tip of syringe system was quantitatively eluted by different types of acids at different levels for 2–6 aspirating/dispensing cycles. The extracted Sb(III) ions with modifiers were directed into the graphite furnace atomic absorption spectrometry for analysis. The limit of detection (LOD), limit of quantification (LOQ) and preconcentration factor (PF) for Sb(III) was found to be 6 ng L−1, 20 ng L−1 and 100. The RSD value was found to be 4.2%. The standard addition method and certified reference materials were checked for accuracy and validity of method. The developed method was effectively applied for the determination of total and inorganic species of Sb(III) and Sb(V) in different types of water samples, whereas only total Sb was determined in acid digested soil, Tuna fish, rice, spinach, black tea, mixed fruit juice and ice tea samples.

Ultrasonic assisted dispersive liquid-liquid microextraction method based on deep eutectic solvent for speciation, preconcentration and determination of selenium species (IV) and (VI) in water and food samples

A novel ultrasound-assisted liquid phase microextraction (UALPME) based on environmental friendly extractants, deep eutectic solvent (DES) was first time presented for speciation of selenium. In present study, five DES solvents of different composition was prepared and used as efficient extractive medium for hydrophobic chelate of Se(IV) with 3,3′-Diaminobenzidine (DAB). The total inorganic Se species were determined after pre-reduction of Se(VI) to Se(IV), prior to applying developed method. The concentration of Se(VI) was calculated by the difference of Se(IV) values and total selenium contents. The concentration of Se in DES rich phase was measured with electrothermal atomic absorption spectrometer (ETAAS). The effects of different parameters on extraction efficiency of study analyte, including pH, ligand concentration, type and volume of DES, sonication time, volumes tetrahydrofuran and aqueous samples were examined. At the optimum conditions, limit of detection and quantification, preconcentration factor, and relative standard deviation (RSD %) were determined as 4.61ngL−1, 15.4ngL−1, 50% and 4.1%, respectively. The accuracy of the presented method was confirmed by analysis of certified reference material and standard addition method for different water and ice tea samples. The developed method was effectively applied to real water and food samples.

Unspecified duo–trio tests can be as powerful as the specified 2-AFC: Effects of instructions and familiarization procedures on cognitive decision strategies

Using signal detection theory (SDT) and Thurstonian analysis, it has been possible in the food industry to make various business decisions such as reformulations and cost reductions based on the degree of consumer sensory discriminability by applying equivalence/difference testing. To achieve more efficient decision-making, it is important to investigate a theoretically and operationally more powerful consumer discrimination test method. Cognitive decision strategies used in discrimination methods largely determine relative test power and thus are of theoretical and practical significance. The goal of this study was to investigate if test procedures using a constant-ref. duo–trio design enable untrained/naïve subjects to use a powerful 2-AFC strategy. Although previously the constant-ref. duo–trio design showed operational superiority to other unspecified test methods, the ‘comparison of distance’ (COD) strategy which is conventionally assumed for the duo–trio, lacks theorized power. The tested variables included two versions of duo–trio design, different familiarizations, instructions and experimental session designs. Three different iced tea samples were discriminated from a reference by 263 untrained/naïve subjects using 5 different duo–trio test procedures. Results showed that untrained/naïve subjects were able to perform the duo–trio with the reference presented twice, first and middle (DTFM) as a 2-AFC procedure, even with multiple pairs in a block design, after only two reference tastings with the information of the constant-reference. The duo–trio preceded by specified tetrad tests also showed potential as another efficient two-sequence test design. These results suggest that such constant-ref. duo–trio protocols using a 2-AFC strategy can be an alternative to the unspecified triangle and tetrad test.

Evaluation of ice-tea quality by DART-TOF/MS.

DART (Direct Analysis in Real Time) coupled with Time-of-Flight Mass Spectrometry (TOF/MS) has been used for analyses of ice-teas. The article focuses on quality and authenticity of ice-teas as one of the most important tea-based products on the market. Twenty-one samples of ice-teas (black and green) were analysed. Selected compounds of ice-teas were determined: theobromine, caffeine, total phenolic compounds, total soluble solids, total amino acid concentration, preservatives and saccharides were determined. Fingerprints of DART-TOF/MS spectra were used for comprehensive assessment of the ice-tea samples. The DART-TOF/MS method was used for monitoring the following compounds: citric acid, caffeine, saccharides, artificial sweeteners (saccharin, acesulphame K), and preservatives (sorbic and benzoic acid), phosphoric acid and phenolic compounds. The measured data were subjected to a principal components analysis. The HPLC and DART-TOF/MS methods were compared in terms of determination of selected compounds (caffeine, benzoic acid, sorbic acid and saccharides) in the ice-teas. The DART-TOF/MS technique seems to be a suitable method for fast screening, testing quality and authenticity of tea-based products.

Evaluation of Tungsten Coil Atomic Emission Spectrometry for the Direct Determination of Al in Tea Infusions and Iced Tea

This work describes the determination of aluminum in tea infusions and iced tea by tungsten coil atomic emission spectrometry (WCAES). The instrumentation is simple, inexpensive, and potentially portable. It uses a tungsten filament extracted from 150 W, 15 V commercially available slide projector light bulbs as electrothermal atomizer. A simple power supply that provides a constant potential is used to heat the coil. Tea infusions were directly analyzed by application of an optimized heating program. In order to avoid matrix interferences, the iced tea samples were diluted with an oxidizing mixture composed of hydrogen peroxide and nitric acid and also analyzed by a tailored heating program. Aluminum was quantified in all samples, and the results were in agreement with those obtained by inductively coupled plasma optical emission spectrometry at a 95 % confidence level. The limit of detection and the relative standard deviation for a solution containing 2.5 mg L−1 Al (n = 10) were determined, and the values were 0.09 mg L−1 and 5.1 %, respectively.

Carrier element-free coprecipitation and speciation of inorganic tin in beverage samples and total tin in food samples using N-Benzoyl-N,N-diisobutylthiourea and its determination by graphite furnace atomic absorption spectrometry

A new, simple, rapid and selective separation, preconcentration and speciation of Sn(II) and Sn(IV) has been developed. The procedure is based on coprecipitation of Sn(II) on N-Benzoyl-N,N-diisobutylthiourea without carrier element. While Sn(II) can be quantitatively precipitated on N-Benzoyl-N,N-diisobutylthiourea in the pH range of 8.0–9.0, recovery of Sn(IV) was below 10%. Total tin was determined after the reduction of Sn(IV) to Sn(II) with 0.1 M NaBH4 in 1 M NaOH solution. Sn(IV) concentrations were calculated as difference between total tin and Sn(II). Determination of tin concentrations was performed by graphite furnace atomic absorption spectrometry (GFAAS). Various analytical parameters including pH, amount of precipitant, sample volume, etc. were optimized. The effects of matrix ions were also examined. Enrichment factor was found as 50. The relative standard deviation was 5%. The detection limit was found 0.013 μg L−1 for Sn(II). The validation of this method was performed by using certificate reference materials (NIST SRM 1568a Rice flour and NRCC DORM-2 Dogfish muscle). Optimized method was applied to bottled mineral water, soda and ice tea samples for tin speciation. This procedure was also applied to microwave digested food samples for the determination of total tin.

Determination of Inorganic Elements in Teas Using Inductively Coupled Plasma Optical Emission Spectrometry and Classification with Exploratory Analysis

Multivariate optimization was employed to obtain the best conditions of the inductively coupled optical emission spectrometer (ICP OES) (nebulization gas flow rate of 0.47 L min−1 and applied power of 1.36 kW) for the determination of Al, Ba, Ca, Cu, Fe, K, Mg, Na, and Mn in 27 green tea samples. In the hierarchical cluster analysis, it was possible to observe the formation of five different groups (imported Japanese samples, samples without specifications, organically cultivated samples, samples in capsules, and ready-to-drink iced tea samples) besides the separation according to brand. In the principal component analysis we verified that the first four main components explained 99.98 % of the total variance. The ICP OES technique and the exploratory analysis were shown effective tools that can be used jointly in the quality control and classification of green tea samples.

Fluoride Concentration and pH of Iced Tea Products

The objective of this study was to determine the fluoride concentration and pH of 44 iced tea samples and hence to assess the possible role of these beverages as systemic fluoride source as well as their potential cariogenic and erosive character. Ten tea samples were available as a granular instant powder, and 34 as ready-to-drink liquid products. The iced teas contained different types of sugar alone or in combination with maltodextrin, glucose syrup and noncaloric sweeteners. In one product, only acesulfame and aspartame were established. All samples contained lemon juice or citric acid as an additive. The pH ranged from 4.04 to 2.63 and the titrated amount of base to pH 7.0 from 0.75 to 2.39 mmol NaOH/50 ml. The fluoride concentrations measured were <0.6 ppm in 14 products, 0.6–1.0 ppm in 10 products, 1.1–1.5 ppm in 16 products, 1.6–2.0 ppm in 2, and >2.0 ppm in another 2 products. In conclusion, most of the iced teas studied contained considerable fluoride concentrations. If infants ingest larger amounts of them because of their sweet taste, there is a risk of uncontrolled overdosing as a result of additional fluoride intake from other sources at the same time. Furthermore, the majority of the products revealed a highly cariogenic character and finally, all the iced teas appear to be acidic enough to cause dental erosion if these refreshments were excessively consumed from nursing bottles.