Sensory Evaluation Research Articles

Differences and correlations between industrial experts and semi-trained assessors in the sensory evaluation of strong-aroma baijiu using rate-all-that-apply.

Baijiu has rich and complex sensory characteristics, and how to make the sensory analysis results given by baijiu industrial experts better understood by consumers has been attracting a lot of attention. In this study, 35 strong-aroma baijiu samples were evaluated by 12 industrial experts and 21 semi-trained assessors, respectively, using rate-all-that-apply (RATA) methods, which involved 2 groups of lexicons generated by the 2 panels. The results showed that the RATA method was suitable for analyzing and distinguishing different baijiu samples by both industrial experts and semi-trained assessors. Although the industrial experts and the semi-trained assessors selected very different lexicons to describe the same strong-aroma baijiu samples, most descriptors from the expert evaluators are either positively or negatively correlated with the semi-trained assessors, such as the attributes "aldehyde," "mud," "multi-grain," and "scorched," and these attributes are effective in distinguishing different strong-aroma baijiu samples. These correlations could enable the marketing promotion and consumer evaluation of baijiu products in the future. PRACTICAL APPLICATION: The result could help baijiu market, in particular the worldwide beverage market, better understand how different baijiu samples are described and evaluated by industrial experts, and further enable the marketing promotion and consumer evaluation of baijiu products in the future.

The use of mare's milk for yogurt ice cream and synbiotic ice cream production.

During the last years, growing interest in the use of mare's milk in food production is observed. The subject of the study was to evaluate the feasibility of mare's milk for the production of yogurt ice cream and synbiotic ice cream. Four variants of mare's milk ice cream were developed: ice cream with yogurt bacteria without inulin (YO) and with 2% of inulin (YO+I), synbiotic ice cream with 2% inulin and Lacticaseibacillus rhamnosus (LCR+I) and with Lactiplantibacillus plantarum (LP+I). Ice creams were enriched with inulin in order to evaluate its influence on the viability of LAB and on the product quality. Physicochemical, textural and sensory analyses were performed. Count of viable bacteria cells was also evaluated. Obtained ice creams did not differ in terms of protein, fat and total solids content (1.85-1.91%, 7.33-7.58% and 24.66-26.96% respectively), but differed in acidity. Ice cream YO, the only one without inulin, had the highest acidity, what suggests that inulin decrease this parameter. Regardless the type of LAB starter culture and inulin addition, samples had the same range of overrun (35.20-44.03%) and melting rate (73.49-79.87%). However the variant of ice cream influenced textural properties and colour parameters. All obtained mare's milk ice creams had high overall sensory quality. It was noticed, that ice cream with inulin had higher count of LAB (>7logCFU/g), than sample without inulin (>6logCFU/g). In conclusion, mare's milk may be considered as feasible raw material for yogurt ice cream and synbiotic ice cream production.

New Sweet-Tasting Gypenosides from "Jiaogulan" (Gynostemma pentaphyllum) and Their Interactions with the Homology Model of Sweet Taste Receptors.

Gynostemma pentaphyllum has been used as an herbal tea, vegetable, and dietary supplement for hundreds of years in East Asia. The sweet variety, grown in large areas in Fujian Province, China, is an essential source of "Jiaogulan" herbal tea. However, its sweet components are unknown. To investigate the sweet constituents of Fujian "Jiaogulan" and discover new natural high-potency sweeteners, phytochemical and sensory evaluations were combined to obtain 15 saponins, of which 11 (1-11) were sweet-tasting, including 2 new ones with sweetness intensities 20-200 times higher than that of sucrose, and four (12-15) were bitter-tasting. Their structures were elucidated using spectroscopic methods (NMR, MS, IR, UV), hydrolysis, and comparison with literature data. The contents of the 15 saponins were quantitatively analyzed using UPLC-MS/MS in multiple reaction monitoring mode. The contents of 1 and 2 sweet-tasting gypenosides were 9.913 ± 1.735 and 35.852 ± 1.739 mg/kg, respectively. The content of the sweetest compound (6) was 124.969 ± 0.961 mg/kg. Additionally, compound 4 was the most abundant sweet component (422.530 ± 3.702 mg/kg). Furthermore, molecular docking results suggested interactions of sweet saponins with sweet taste receptors. In general, this study revealed the material basis of the Fujian "Jiaogulan" taste.

Enrichment of Bakery Products with Antioxidant and Dietary Fiber Ingredients Obtained from Spent Coffee Ground

Spent Coffee Ground (SCG) is the main coffee industry by-product, rich in dietary fibers and polyphenols. The extractable material of SCG was fractionated, and the phenolic compounds were identified and quantified. Chlorogenic and neochlorogenic acids were identified as the main phenolic components, and the Total Phenolic Content (TPC) of SCG was determined to be 2.16% (dry SCG basis). Furthermore, SCG was characterized in terms of Total Dietary Fiber content, which amounted to 66%. The SCG was valorized for the development of a bakery product (cookie) enhanced with fiber and bioactive polyphenols. Cookies were produced with the addition of 4% and 7% dry and defatted SCG (baked cookie basis). The produced cookie prototypes presented TPC and dietary fiber dependent on the addition level of SCG. TPC values were determined at 588 and 1017 ppm, while dietary fiber values were at 2.7 and 4.6%, respectively. The shelf life of the cookies was monitored over 143 days at three different temperatures (25 °C, 35 °C, and 45 °C) in terms of texture (hardness), color, Peroxide Value (PV), and TPC. It was observed that the PV value significantly increased in samples with incorporated SCG, stored at 45 °C, while in those stored at 25 °C and 35 °C, PV remained at low levels. The TPC of the SCG-enriched samples remained practically constant during the shelf life analysis, while color and hardness increased (mathematically modeled). SCG-added cookies were characterized by increased darkness, increased hardness, and a mild (desirable) coffee flavor. The overall sensory impression scores for 0%, 4%, and 7% SCG-added cookies were 7.5, 8.0, and 8.2, respectively. Based on sensory evaluation test results, the shelf lives of 0%, 4%, and 7% SCG at 25 °C were 359, 435, and 471 days, respectively. Overall, SCG is a potentially valuable ingredient that can be used to develop innovative food (baked) products with enhanced nutritional value and increased shelf life.

Impact of Cricket and Caterpillar Meal Supplementation on the Nutritional Profile and Consumer Acceptability of Cookies

The quality of cookies produced from wheat flour, cricket, and caterpillar meal blends was evaluated. This was done to examine the effect of adding edible cricket and caterpillar meals on the nutritional and sensory quality of wheat-based cookies. Edible crickets and caterpillars were purchased from local farmers in Benue state, de-gutted, washed, oven-dried, sorted, milled, and sieved to produce their respective meals. The meals were mixed in wheat flour: edible insects ratios of 95:5, 90:10, 85:15 and 80:20 for Cricket and Caterpillar meal blends, respectively. However, samples 100:0 were not mixed and contained 100% wheat flour. The samples were subjected to functional analysis of proximate composition, mineral, vitamin, amino acid profile, physical properties analysis, and sensory attributes evaluation. The result generated from the study was subjected to analysis of variance (ANOVA) and the Duncan multiple range test (DMRT) was used for mean separation at the probability level of significance of 5%. While the protein, fat, ash, crude fibre, and moisture content of the cookies increased with increasing amount of edible insect meal incorporated into the formulation, the carbohydrate content of the cookies decreased significantly (p<0.05). All minerals evaluated in the study (Ca, Zn, K, P, Na, Mg, and Fe) increased with the increase in the amount of edible insect meals in the formulations. An increase in vitamin content was also observed in the cookies, but this increase was insignificant (p>0.05). There was a significant increase in all essential and non-essential amino acid content of the cookies as the level of cricket/caterpillar meal in the formulation increased. The addition of up to 20% of edible cricket/caterpillar meals to wheat flour increased all sensory attributes of the cookies. Cookies fortified with caterpillar meal were found to be more nutritious than those fortified with cricket meal. In general, samples 85:15(85% wheat flour + 15% cricket meal) and 85:15(85% wheat flour + 15% caterpillar meal) contained high nutritional content and recorded the best sensory attributes and therefore were selected as the best blends for a wheat flour+cricket meal and wheat flour+caterpillar meal blends for cookies production.

The role of red pepper on the colour and bioactive properties, polyphenols, minerals and sensory evaluation of the wheat breads enriched with red pepper powder at different concentrations

SummaryIn current investigation, the effect of the breads enriched with red pepper powder at different concentrations (0.5%, 1.0%, 1.5% and 2.0%) on colour parameters, antioxidant activity, total phenolics, flavonoids, phenolic components, minerals and sensory properties was revealed. While the brightness results of the breads L* decreased, there was a significant increase in the a* and b* values. As the concentration of the pepper powder added to bread dough increased, a significant increase was observed in bioactive compounds such as total phenol, antioxidant activity and flavonoids in the bread. It was determined that bread enriched with 1% red pepper powder received the highest sensory scores compared to other breads. The phenolic compound amounts of the breads showed some changes based on the pepper concentrations. Protein amounts of the wheat bread fortified with red pepper powder were specified to be between 9.32 (0.5%) and 9.79% (control). Phosphorus (P) and potassium (K) quantities of the breads were assessed to be between 745.27 mg kg−1 (0.5%) and 846.69 mg kg−1 (2.0%) to 2266.63 mg kg−1 (control) and 2907.38 mg kg−1 (2.0%), respectively. The flavour, smell, colour and texture values of the pepper bread samples varied depending on the added pepper concentration. As a result, the most liked formulation by the consumers was the pepper bread with 1.0% added, followed by 1.5%, 2.0%, 0.5% in decreasing order.

Repercussions of Lactiplantibacillus plantarum HYY‐DB9 and Levilactobacillus brevis GIM 1.773 on the degradation of nitrite, volatile compounds, and sensory assessment of traditional Chinese paocai

SummaryPaocai, as one of the most widely consumed traditional fermented foods in China, is dominated by lactic acid bacteria (LAB), which exert a significant influence on the dynamics of metabolites, microecological changes, and sensory quality. In this study, five different paocai groups were designed for fermentation using Lactiplantibacillus plantarum HYY‐DB9 (LP), Levilactobacillus brevis GIM 1.773 (LB), a mixture of two LABs (LP + LB), pasteurisation (PST), and natural fermentation (NF). Nitrite content, pH, titratable acidity, viable cell counts (LAB and yeasts), metabolites (organic acids and volatile substances), and sensory evaluation were determined for each group. The results demonstrated that the mixed fermentation with two LABs (LP + LB) significantly reduced nitrite content. Organic acids produced by LAB played a crucial role in the degradation process, particularly lactic acid which exhibited the most pronounced effect on nitrite degradation. Furthermore, artificial inoculation of LAB fermentation resulted in improved taste and flavour of paocai along with increased production of alcohols, esters, and acids compared to traditional natural fermentation. These findings have important implications for enhancing paocai quality control and managing nitrite content while also providing an excellent fermentation agent for fermented paocai.

Impact of heat treatment on the flavor stability of Longjing green tea beverages: Metabolomic insights and sensory correlations

The flavor stability of tea beverages during storage has long been a concern. The study aimed to explore the flavor stability of Longjing green tea beverage using accelerated heat treatment trials, addressing the shortage of lengthy storage trials. Sensory evaluations revealed changes in bitterness, umami, overall harmonization, astringency, and ripeness as treatment duration increased. Accompanied by a decrease in L-values, ΔE and an increase in a and b-values. Seventeen non-volatile metabolites and three volatile metabolites were identified differential among samples by metabolomics, with subsequent correlation analysis indicating associations between sensory attributes and specific metabolites. Umami was linked to epigallocatechin 3,5-digallate and alpha-D-glucopyranose, astringency was correlated with ellagic acid and 1-ethyl-1H-pyrrole. Ripeness showed associations with ellagic acid, 6,7-dihydroxycoumarin, heptanal, and benzaldehyde, and overall harmonization was linked to 6,7-dihydroxycoumarin, β-myrcene, α-terpineol, and heptanal. A series of verification tests confirmed the feasibility of accelerated heat treatment trials to replace traditional storage trials. These results offer valuable insights into unraveling the complex relationship between sensory and chemical profiles of green tea beverages.

Nutritional, Anti-Nutritional and Sensory Evaluation of Snacks Produced from Germinated Maize/Bambara Groundnut (Vigna Subterranean) Flours

Background: Bambara nut, an underutilized legume is rich in protein and can improve the nutritional quality of snacks. This study evaluates the nutritional and sensory properties of muffins produced from germinated maize and Bambara groundnut flours. Methods: Maize and Bambara groundnut seeds were germinated (72 hours), oven-dried and milled. The composite flours from the germinated flours were combined with soya oil, tiger-nut milk, date and carrot powder to produce four samples of muffins. The samples were chemically analyzed for proximate, mineral, beta-carotene, and anti-nutrient contents. Then, sensory evaluation was carried out among 20 mothers (20-30) using a 5 hedonic scale. ANOVA and Duncan Multiple Range Test were also used to analyze the data. Results: Protein, fiber and carbohydrate contents of the muffins ranged from 7.63-9.23%, 0.05-0.08% and 70.63-71.55%, respectively. It was found that germination significantly increased protein and iron content of muffins but reduced zinc, calcium, and beta-carotene contents (P<0.001). The muffins contributed above 22% of the RDA regarding energy for children. Muffins produced from the blends provided higher level of protein, calcium, iron and beta-carotene compared to those made from whole wheat flour. There was a significant reduction in anti-nutrient contents of the muffins and germinated flours. The muffin produced from the 80% maize and 20% Bambara nut flour was rated best in terms of nutritional value, taste, and texture. Conclusion: Bambara nut flours could be used to produce nutritious snacks which would contribute to daily energy and protein needs of children.

Evaluating Proximate, Antinutrient, and Antioxidant Activity of Raw and Processed Quinoa (Chenopodium Quinoa Willd) Flour and Developing Food Products by Incorporating Them

Background: This study evaluates proximate, antinutrient, and antioxidant activities of raw and processed quinoa flour (RQF and PQF). Product development and sensory evaluation were also addressed to provide prospects for human consumption. Methods: Quinoa was processed by two methods - soaking and roasting. Some nutrients like moisture, ash, protein, carbohydrate, crude fibre, fat, iron, calcium, vitamin C, phytic acid, saponins, total phenol, and 2,2-diphenylpicrylhydrazyl (DPPH) were analyzed. The recipes were made and conduct acceptability evaluation by a 9-point hedonic scale. The mean, standard deviation, and One-Way Analysis of Variance (proximate, antinutrient, antioxidant) were utilized as the statistical approach for the analysis of data. Results: The study revealed that some nutrient composition of RQF was found to be impressive with moisture (11%), ash (2.1%), protein (16.6%), crude fibre (2%), iron (11.6%), and calcium (76.1%) as compared to PQF; however, carbohydrate (69.9%), fat (9.6%), and vitamin C (9.1%) was increased in PQF, and phytic acid and saponins were decreased in all the PQF. DPPH’ free antioxidant potential was observed that RQF lowered free radical scavenging activity. In all PQF, the total phenol content was both raised and reduced. Also, proximate and antioxidant activity showed significant differences (P<0.05), and antinutrient analysis showed no significant differences (P>0.05). The two recipes were prepared as upma (soaked for 48 h), and chakli (roasted at 145 °C). Sample B of upma (50% semolina with 50% soaked quinoa flour) and sample A of chakli (75% refined flour with 25% roasted quinoa flour) were more acceptable. Conclusion: This study concluded that the use of domestic processing of quinoa seeds decreases some nutrient value compared with RQF and also infers the dietary importance of quinoa.

Impact of different lactic acid bacteria on nitrite degradation and quality of fermented carrot

SummaryIn this study, six groups of carrots were designed and fermented using Weissella paramensenteroides MbWp142 (WP), Levilactobacillus brevis GDMCC 1.773 (LS), Leuconostoc mesenteroides GDMCC 1.774 (SE), mixed fermentation of three lactic acid bacteria (WP + LS + SE), pasteurisation group (BG) and natural fermentation group (CK). GC–MS results indicated that inoculation of WP + LS + SE increased the types and contents of flavour substances such as alcohols, esters and hydrocarbons. Compared with other experimental groups, the peak nitrite value in the LS group was lower due to the production of organic acids by lactic acid bacteria. Sensory evaluation revealed that the quality and flavour of carrot fermented by LS were superior to those fermented by SE, WP and WP + LS + SE. Therefore, Levilactobacillus brevis used as a starter for fermenting carrot can enhance product quality and reduce nitrite accumulation during fermentation.

Exploration of the mechanism of temperature influence on bitter taste of theacrine by activating human bitter taste receptor hTAS2R14

Theacrine, a purine alkaloid derived from Camellia assamica var. kucha, has a distinct bitter taste. Our previous study found the lower recognition threshold of theacrine at 25 °C than 45 °C. This study aims to investigate the bitterness characterizations of theacrine at aforementioned temperatures and its taste perception mechanism. Sensory analysis exhibited higher bitterness intensity for theacrine at 25 °C than 45 °C. Subsequently, flow cytometry was performed to verify the above characterization at the cellular level. It revealed that theacrine could activated the bitter receptor hTAS2R14 and the calcium signal at 25 °C was higher than 45 °C. Ultimately, the interaction mechanism was studied by molecular dynamics simulations, indicating that the conformation of theacrine-hTAS2R14 had a higher binding capacity and better stability at 25 °C. Overall, temperature affected the binding of theacrine to the bitter receptor hTAS2R14, resulting in the stronger bitterness intensity of theacrine at 25 °C than 45 °C.

Effect of temperature on the rheological, textural, and sensory properties of butters from New Zealand market.

Texture and sensory studies at various temperatures are important in evaluating and improving the functionality of butter. While literature is scarce, we evaluated and compared the effect of temperature (5-25°C) on the texture, rheological and sensory properties of commercial butter samples (salted, unsalted, cultured, and spreadable) from the New Zealand market. In addition, the instrumental analyses were compared with the sensory evaluation, to understand the possibility of using instrumental analysis to evaluate consumer liking for different butters. Butter type, temperature, and their type-temperature interaction exhibited significant differences for all instrumental textural parameters. As expected, higher temperature produced softer butter that was more spreadable, liquid-like, less adhesive, less cohesive, had lower storage modulus (G') and lower loss modulus (G″) with the melting of milk fat crystals; however, the rate of change varied for the different butter samples. We have established meltability as the parameter for evaluating butter selection for different applications. The spreadable butter sample exhibited the lowest hardness and G', and highest spreadability (p < .05) at all temperatures, owing to its low solid fat content and the abundance of low-melting triglycerides. The cultured butter sample had the highest melting point, owing to compositional differences. The instrumental and sensory texture analyses were highly correlated, indicating the comparative effectiveness of both approaches for studying the effects of different temperatures on butter textural properties. Overall, our findings provide detailed reference to the dairy industry for butter manufacture, considering variation in fatty acid composition, texture analysis, rheology, and sensory analysis, over the range of storage/usage temperatures.

Willingness to Pay for Blueberries: Sensory Attributes, Fruit Quality Traits, and Consumers’ Characteristics

Understanding consumers’ preferences for fruit quality attributes is key to informing breeding efforts, meeting consumer preferences, and promoting increased market demand. The objective of this study was to assess the effect of fruit quality traits and hedonic sensory evaluation on consumers’ willingness to pay (WTP) for a selection of fresh northern and southern highbush blueberry cultivars. The WTP was elicited by using a double-bounded contingent valuation conducted in conjunction with a consumer sensory test. Two types of models were estimated using either sensory evaluations (i.e., consumer preference and consumer intensity) or instrumental measurement data (i.e., measures of soluble solids, titratable acidity, sugars, acids, and firmness) as explanatory variables to model WTP. Results using sensory evaluations indicated that flavor liking, flavor intensity, and sweetness intensity are key factors that influence consumers’ acceptance and WTP for blueberries. A regression analysis using instrumental measurements indicated that measures related to sweetness and acidity traits are important factors that determine WTP. Higher WTP was associated with higher total sugar content across different levels of total organic acid. The WTP increases with organic acid content, because this is needed for enhanced flavor; however, WTP declines at high concentrations of organic acid. Except for extreme values of firmness, the WTP increased as measures of fruit firmness increased, indicating a consumer preference for firmer blueberries. Overall, the results provided new insights into the relationships between consumer preference and WTP and fruit quality benchmarks to select for improved quality.

Physicochemical and sensory properties of vegan ice cream using upcycled Aquasoya powder

SummaryAquasoya (AS) powder arouses great interest as a cost‐effective vegan ingredient. In our study, AS was used to develop vegan ice cream products. Different total solid content (TSC) (31%, 33%, 35%, 37%, and 39% w/w) of ice cream mix was changed by the addition of AS powder. pH, emulsion properties, brix, colour, viscosity, overrun, melting properties, texture profile analysis (TPA), and sensory evaluations were investigated. The pH of each AS (31%, 33%, 35%, 37%, 39%) ice cream mix sample was 5.70–5.81, with no significant variance in AS content. Notably, the 39% AS led to higher Brix and viscosity scores. Moreover, the highest overrun in AS ice cream was observed in the sample containing 39% TSC. In contrast, the 31%, 33%, and 35% samples exhibited lower viscosities. However, the 37% and 39% samples displayed higher viscosities, leading to a longer‐lasting appearance. Regarding sensory evaluation, the 39% sample received the highest ratings for overall taste intensity, colour, smell, bean smell, flavour, taste, astringency, and bitterness. However, it scored the lowest for sweetness, softness, and melting degree. Generally, a higher AS content corresponds to stronger overall characteristics. Additionally, acceptance evaluations showed that panels tended to favour ice cream with lower AS content. All these findings suggest that AS ice cream could be potentially developed using vegan ingredients, offering enhanced nutritional and sensory attributes while serving as an effective emulsifier.

Effects of Dioscorea opposita mucilage addition on the physicochemical properties, texture, and stability of set-type yogurt

Dioscorea opposita mucilage (DOM), a polysaccharide-protein polymer with antioxidant activity, can be served as a natural ingredient in nutritional yogurts. The effects of DOM addition at different concentrations (2%, 4%, 6%, 8%, 10% and 12% w/w) on the total number of lactic acid bacteria, pH, titratable acidity, syneresis, viscosity, texture, color and sensory evaluations of full-fat yogurts and skimmed yogurts during 21 days storage at 4 °C were investigated. The results suggested that DOM could improve the growth of LAB, strengthen the network and gelation of yogurt, and thicken the dispersion, which led to the significant decrease in pH and cohesiveness, and drastic increase in the syneresis, firmness and adhesiveness. Additionally, sensory evaluation revealed that the overall liking scores of full-fat yogurts (8.1–8.7) were higher than those of skimmed yogurts (7.9–8.3), which exhibited strong correlations with firmness and viscosity of set-type yogurts. Although DOM addition affected the sensory undesirably, such as creaminess, the thickness and overall liking were improved, especially for the skimmed yogurts. In summary, 8% w/w DOM could effectively improve the texture, quality and stability of set-type yogurts. This study provides new applications in functional dairy products and promotes the value of the by-products of D. opposita.

Unraveling the chemosensory characteristics on different types of spirits based on sensory contours and quantitative targeted flavoromics analysis

Due to differences in raw materials and production processes, different spirits exhibit various flavor even if undergo distillation operation. In this study, sensory analysis could clearly distinguish 5 types spirits, and had been validated through quantitative targeted flavoromics analysis. Consequently, 44 potential differential markers between 5 types spirits were screened. Among, 34 definite differential markers were further confirmed to be highly correlated with target sensory attributes and could effectively distinguish types of spirits. Ultimately, 14 key differential markers (including 2-methylbutane, linalool, acetaldehyde, d-limonene, β-myrcene, phenylethyl alcohol, phenethyl acetate, heptyl formate, ethyl octanoate, ethyl decanoate, ethyl pentanoate, ethyl hexanoate, hexanoic acid, and ethyl hexadecanoate) could reveal the chemical sources of spirit sensory and serve as targets for identifying different types of spirits. Overall, the results of flavoromic characterization of 5 types spirits provided a significant step forwards in understanding of differentiation of spirits by sensory coupled with quantitative, and statistical analysis

Changes in raspberry sensory quality after harvest as affected by CO2 atmospheres

CO2 atmospheres have the potential to influence raspberry (Rubus idaeus L.) sensory quality after harvest. Our study determined the optimal postharvest atmosphere to extend shelf life without negatively impacting sensory quality. Raspberry fruit were stored at 5 ℃ in 15, 8, 5 or 0.03 kPa CO2 in combination with 6, 13, 16 or 21 kPa O2, respectively. A trained sensory panel conducted a descriptive sensory evaluation of the raspberry fruit after 5, 10, and 13 d of storage. Raspberries stored in 15 kPa CO2 with 6 kPa O2 (15 kPa) atmosphere followed by that in 8 kPa CO2 with 13 kPa O2 (8 kPa) atmosphere had higher firmness than that in 5 kPa CO2 with 16 kPa O2 (5 kPa) and 0.03 kPa CO2 with 21 kPa O2 (0.03 kPa) atmosphere. Panelists found that raspberries stored in 8 kPa and 15 kPa CO2 atmosphere had the least off-flavor and highest tartness. Raspberries stored in 8 kPa scored highest in raspberry flavor with substantial juiciness and sweetness scores. The fermentative volatiles acetaldehyde and ethanol were higher in raspberries stored in 15 kPa despite the low off-flavor scores, while most other raspberry volatiles decreased with increasing CO2 concentration, including flavor-related volatiles α-ionone, α-terpineol, limonene and linalool. After 10 d, the quality of raspberries stored in 0.03 kPa or 5 kPa atmosphere had degraded considerably. While 15 kPa atmosphere prolonged shelf life the longest, 8 kPa atmosphere prolonged shelf life to 10 d while maintaining sensory quality and was the best overall atmosphere.

Study on the changes during the fermentation of the wine prepared from palm (Phoenix sylvestris) sap

The sugary sap of different palm trees is fermented to create palm wine, an alcoholic beverage. This work was aimed at studying the changes that occur during the fermentation process of wine made from the sap of the wild date palm species Phoenix sylvestris. At first, the best age of the palm tree was determined by observing total soluble solid and sap yield for 24 h and was found to be middle-aged palm plants (15–40 years old). Pure wine yeast (Saccharomyces cerevisiae SC22) and a natural starter culture were added to the palm saps, adjusting the total soluble solid (TSS) to 21.5° brix (°Bx). Total titratable acidity, pH, volatile acidity, reducing sugar, non-reducing sugar, total sugar, alcohol content, ester content, and aldehyde contents were the parameters under investigation. The statistical analysis showed significant (p ≤ 0.05) changes in the physico-chemical and volatile constituents of palm sap during the fermentation process in both systems. Sensory evaluation revealed that palm wine fermented with pure yeast culture was significantly superior to natural, spontaneously fermented wine. The acceptability test showed that the ideal characteristics of palm wine are cloudy in appearance, fruity in aroma, and sweet in taste.

Enhancing bioactive compounds retention in pomegranate juice powder through foam mat drying

AbstractThe effect of addition of whey protein isolate (WPI; 0%, 5%, 7.5% and 10%) and carboxy methyl cellulose (CMC; 0%, 0.25%, 0.5% and 0.75%) was studied for its foaming properties and stability in pomegranate juice (PJ). High‐quality powders can be produced from fruit juices and heat‐sensitive food items using foam mat drying (FMD). The PJ foam with 10% WPI, a foaming agent, and 0.25% CMC, a stabilizer had high foam expansion (FE) (455.28%) and low foam density (FD) (0.2030 g/cc) and foam drainage volume (FDV) (20.10 mL). The PJ foam was subjected to different drying temperatures (50, 60 and 70°C) and thickness (3 and 6 mm). The drying temperature of 60°C and foam thickness of 3 mm were found to be the acceptable drying conditions based on drying time (180 min) and retention of bioactive compounds. At optimum drying conditions, the retention of phenols, anthocyanin, ascorbic acid, and antioxidant capacity was 97.86%, 83.90%, 77.29%, and 87.11%, respectively. The sensory evaluation of the reconstituted foam mat dried pomegranate juice powder (FPJP) showed lower overall acceptability scores than fresh juice (FJ), but the overall acceptability of the powder dried at optimum drying conditions was within liking limits (&gt;6). FPJP has an amorphous nature with a particle size of 3564 nm and a porous and irregular structure. Bioactive compounds in FPJP were studied after 8 months of storage, with higher retention of bioactive compounds in refrigerated conditions.Practical applicationThe studies revealed that foam mat drying is suitable for the pomegranate juice which has high moisture and sugar content. It requires shorter drying time of 180 min. for drying up to moisture content of 4% (db). The foam mat dried juice powder obtained at optimum drying conditions has retained higher bioactive compounds and has higher sensorial acceptability when compared with the other treatment combinations. This drying process requires low initial investment and can easily be scaled up to the commercial level thus making it profitable business venture. Further, higher storage stability up to 8 months, low volume and consequent low transport cost improves the technical and financial viability of the process in industrial application. The Foam mat dried pomegranate juice developed can be used in many food products such as reconstituted beverages, ice creams, confectioneries, etc.