Raspberry Juice Research Articles

Changes in the Physicochemical Characteristics, Free and Bound Aroma Compounds in the Raspberry Juice during Storage

The changes in the physicochemical characteristics of raspberry juice during storage were studied. Free aroma compounds during storage were analyzed by solid-phase microextraction/gas chromatography–mass spectrometry. Bound fractions were isolated and extracted with methanol and Amberlite XAD-2 resin and then hydrolyzed by almond β-glucosidase. The content of the ascorbic acid was reduced by 47 and 31% in fresh and processed juice after 20 days of storage, respectively. A total of 23 free aroma compounds were identified in the raspberry juice. Only 12, 10, 9 and 10 free aroma compounds were found in this juice after 5, 10, 15 and 20 days of storage, with total contents of 1,614, 696, 806 and 1,103 μg/L. C13-norisoprenoids were the predominant compounds during storage. In total, 14 bound aroma compounds were found in this juice. Benzoic acid was the most abundant benzene compound. Most of the bound fractions were missed during storage. Practical Applications Aroma attribute is one of the most important factors to the quality of the fruit juice. It changed seriously during hot processing or storage. The main reason was that the aroma compounds in the juice were transferred, degraded or evaporated. Nevertheless, glycosidically bound aroma compounds might be released during processing or storage. The findings of this research revealed that most of the physicochemical characteristics remained stable during storage, except ascorbic acid. The free and bound aroma compounds of the raspberry juice changed a lot during storage. Most of these compounds decreased or were missed during hot processing and storage. The information gained from this research could be further applied in the raspberry and food industry to improve the quality of the juice during processing and storage.

Bioautographic Screening of Antibacterial Properties of Selected Juices, Herbal Infusions, and Cosmetic Ingredients

Polyphenols are the products of plant immune system and they characterize with well pronounced antioxidant, antibacterial and antifungal properties. Owing to a wide spectrum of native polyphenols, herbal infusions, fruit juices, wines, and cosmetic substrates are among the most popular health-care products and for this reason, they undergo intense scientific investigations. Antibacterial properties of botanical material can prove particularly helpful in efforts aiming to lower the amounts of preservatives in alimentary, pharmaceutical, and cosmetic products. In this study, a comparison is presented of antibacterial properties for (i) nine samples of red wines and the wine extracts, (ii) 13 samples of plant extracts and the extracts thereof used in cosmetic preparations, and (iii) fruit juices and infusions prepared of dried fruits. All these botanical materials are widely used in pharmaceutical, cosmetic, and/or alimentary industry. As a rapid screening technique, a simplified version of thin-layer chromatography with bioautographic detection (TLC-BD) was applied, known as the dot blot test with bioautographic detection. This test makes use of chromatographic plates and all details of the procedure are the same as for TLC-BD, except for the fact that the chromatogram is not developed and an assessment of antibacterial properties is carried out for a whole sample spotted on to chromatographic plate, and not for its separated fractions. As a result, the most potent antibacterial action was observed with the pasteurized pure raspberry juice and an infusion made of dried black elderberry fruit.

베리류 열매 착즙액의 항산화 및 항균 활성

This study was performed to evaluate and compare the antioxidant and antimicrobial activities of various berry juices (cherry, grape, blueberry, aronia, cranberry, and raspberry). The cherry, aronia, and cranberry juices included higher levels of total polyphenol than the other berry juices. The DPPH radical scavenging activity of various berry juices increased according to the juices concentration. The scavenging activity of DPPH radicals by the aronia, cranberry, and raspberry juices was higher than those of other samples and was in the following order: aronia > cranberry > raspberry. The FRAP values of 100% aronia juice was the highest among the samples, which was more than five times higher than grape juice at a concentration of 25%. The cranberry and raspberry juices exhibited a strong inhibitory effect against important food-borne bacteria, and in general, the berry juices inhibited the growth of Gram-negative bacteria more than that of Gram-positive bacteria. The cranberry and raspberry juices exhibited high antimicrobial activities against important food-borne bacteria at a concentration of 100% and 75%, however, they did not affect food-borne bacteria at a concentration below 10%. These results suggest that aronia, cranberry, and raspberry may be used effectively as natural additives and as

Phenolic Profile and Antioxidant Activity of Polish Meads

The purpose of this study was to evaluate phenolic profile and antioxidant activity of ten different meads of 1:1 and 1:2 types, produced with addition of fruit juices, root spices, and herbs. The total phenolic content in meads varied from 15.27 to 70.80 mg/dm3. The meads originated from dark honeys exhibited the highest antioxidant activity. The predominant phenolic compounds in meads were hydroxybenzoic acids, especially gallic and protocatechuic acid, originated mainly from honeys. Whereas, among the hydroxycinnamic acids, the major phenolic was chlorogenic acid, derived mainly from plant additives used in meads production. A principal component analysis was applied in order to differentiate the investigated meads. The 1:2 meads type could be best described by chlorogenic acid. Among the 1:1 meads type, those made from the dark honeys could be best described by gallic, p-coumaric, and protocatechuic acid while those made with addition of blackcurrant and raspberry juice could be described by caffeic and ferulic acid.

Sugars and Citric Acid Differently Modulate DPPH Antioxidant Activity in Polyphenol‐rich Fruit Juices

The objective of this study was to further characterize the interactions of citric acid, sorbitol, sucrose on the DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) antioxidant activity of polyphenol‐rich juices. Polyphenols were isolated from aronia, raspberry, apple, grape, and cherry juices. Polyphenols were recombined with various levels of citric acid (0 to 1%, w/v) and sugars (0 to 30%, w/v) and DPPH scavenging was subsequently measured near the IC50 value of polyphenol fractions. Sorbitol and citric acid inhibited DPPH activity up to 15 and 10%, respectively in aronia polyphenols. Sorbitol had differential effects on DPPH activity of juice polyphenols. Sorbitol increased DPPH inhibition by 1, 4, and 5% for cherry, grape and raspberry polyphenols, while it was decreased apple juice by 58.1%. Sucrose reduced DPPH inhibition of apple and grape polyphenols 25 and 29% while it increased by 8.0 and 5.6% for raspberry and cherry polyphenols. Citric acid increased apple and raspberry juice polyphenol antioxidant activity by 7.4 and 11%, but did not affect cherry or grape juice polyphenols. Therefore, common sweeteners and citric acid differentially affect in vitro DPPH antioxidant activity of fruit juice polyphenols. This implies that non‐polyphenol components of fruit juices significantly contribute to a widely‐used in vitro measure of antioxidant capacity.This work was supported by an Undergraduate Research Award to Sarah Kranz from the University of Connecticut Office of Undergraduate Research.

Sensory profiles and consumer acceptability of a range of sugar-reduced products on the UK market

Current UK intake of non-milk extrinsic sugars (NMES) is above recommendations. Reducing the sugar content of processed high sugar foods through reformulation is one option for reducing consumption of NMES at a population level. However, reformulation can alter the sensory attributes of food products and influence consumer liking. This study evaluated consumer acceptance of a selection of products that are commercially-available in the UK; these included regular and sugar-reduced baked beans, strawberry jam, milk chocolate, cola and cranberry & raspberry juice. Sweeteners were present in the reformulated chocolate (maltitol), cola (aspartame and acesulfame-K) and juice (sucralose) samples. Healthy, non-smoking consumers (n=116; 55 men, 61 women, age: 33±9years; BMI: 25.7±4.6kg/m2) rated the products for overall liking and on liking of appearance, flavor and texture using a nine-point hedonic scale. There were significant differences between standard and reduced sugar products in consumers' overall liking and on liking of each modality (appearance, flavor and texture; all P<0.0001). For overall liking, only the regular beans and cola were significantly more liked than their reformulated counterparts (P<0.0001). Cluster analysis identified three consumer clusters that were representative of different patterns of consumer liking. For the largest cluster (cluster 3: 45%), there was a significant difference in mean liking scores across all products, except jam. Differences in liking were predominantly driven by sweet taste in 2 out of 3 clusters. The current research has demonstrated that a high proportion of consumers prefer conventional products over sugar-reduced products across a wide range of product types (45%) or across selected products (27%), when tasted unbranded, and so there is room for further optimization of commercial reduced sugar products that were evaluated in the current study. Future work should evaluate strategies to facilitate compliance to dietary recommendations on NMES and free sugars, such as the impact of sugar-reduced food exposure on their acceptance.

Developing spray-dried powders containing anthocyanins of black raspberry juice encapsulated based on fenugreek gum

Spray-dried powder of black raspberry juice was optimized using response surface methodology (RSM). The juice was prepared by dispersions formulated with different coating materials including maltodextrin (MD with DE 6%, 6.59–26.41%), fenugreek gum (FG, 0.33–1.17%) and microcrystalline cellulose (MCC; 0.66–2.34%). Scanning electron microscopy and analyzing laser diffraction particle size were successfully used to relate the microstructure and dominant mechanisms on the stable dispersions to achieve the highest quality powder. Perturbation and 3D surface plots were drawn for each of the responses from the mathematical models. Second-order polynomial models with high R2 (0.972–0.989) values were constructed for each powder physicochemical properties namely yield, solubility, total anthocyanin content (TAC), and total phenolic content (TPC). The linear effect of MD concentration had a significant (p<0.05) term in all constructed models. The optimal conditions were: MD concentration of 20.0%, FG content of 0.93%, and MCC concentration of 1.74%. These optimum conditions were powder recovery of 82.72%, solubility of 82.2%, TAC of 280.76mg Cy3G/100mL and TPC of 2.0491mgGAE/gdw. A high agreement between experimental and predicted values was found.

Retention Rate Enhancement of Antioxidant and Cyaniding 3-O-Glucoside Components of the Reconstituted Product from Spray-Dried Black Raspberry Juice by Optimizing Process Parameters

The effects of four operating parameters involved in the spray-drying process, including air inlet temperature (120–150°C), air flow rate (3.5–5.0 m3/h), feed flow rate (2–10 mL/min), and aspirator rate (50–70 m3/h), to produce black raspberry juice powders with the highest retention rate of healthy functional components were optimized using a response surface design. Second-order polynomial models with high R 2 (0.955–0.972) values were developed using multiple linear regression analysis. Results showed that the most significant (p < 0.05) process conditions that affected the antioxidant activity and cyanidin-3-O-glucoside content (C3GLU) of powders respectively were the quadratic effects of air inlet temperature and air flow rate and quadratic terms of air and feed flow rates. Laser diffraction particle size analysis and scanning electron microscopy were used to relate the microstructure and quality features. The lowest EC50 (0.0060 mL juice/g 1,1-diphenyl-2-picrylhydrazyl [DPPH]) and the highest C3GLU (4.721 mg/100 mL) values were achieved at an inlet temperature of 120.0°C, air flow rate of 4.20 m3/h, feed flow rate of 8.65 mL/min, and aspirator rate of 55.87 m3/h.

G269 The CAKE Study: Cake Aids Knowledge and Experience

Background‘See one, do one, teach one’ has long been the philosophy when it comes to developing procedural skills in medicine. Anecdotally trainees do not feel confident when undertaking procedures such...

Shelf life stability of lactobacilli encapsulated in raspberry powder: Insights into non-dairy probiotics

Aim: Study the shelf-life quality changes in raspberry juice with encapsulated lactobacilli (Lactobacillus rhamnosus NRRL B-4495 and Lactobacillus acidophilus NRRL B-442) obtained by spray drying and understand the various factors involved. Methods and results: Raspberry powder was obtained from spray drying lactobacilli and raspberry juice with maltodextrin as an additive. Shelf life of the powder was analyzed over a period of 30 d. Acid and bile tolerance and antibiotic resistance was compared before and after spray drying. Water activity, survival, and scanning electron microscope images were also measured during the shelf life. Conclusions and significance: A combination of processing conditions: inlet temperature (°C), maltodextrin to juice solids ratio and inlet feed rate (ml/min) during spray drying had a significant role on the survival of lactobacilli during shelf life. Refrigerated storage provided a higher shelf-life stability with regards to CFU/g (as high as 84% on day 0 and 98% retention by the end of 30 d) compared to room temperature storage. Probiotic properties during shelf life are affected by the processing conditions and encapsulated food matrix. Thus, understanding these aspects in vitro during shelf life gives us a brief insight into the future of non-dairy probiotics.

Different antimicrobial effects of raspberry depending on the method of active components isolation

Raspberry fruit exhibits numerous beneficial effects for veterinary and human medicine. One of those effects is antimicrobial activity, because of its diverse chemical composition. Adequate processing of plant material is the most important part of examining their activities. Processing conditions affect the separation of chemical substances in the test sample i.e. different methods can lead to separation of different active principles. Raspberry juice was produced by filtration. Raspberry pomace, the residue from the pressing of raspberries for juice production was extracted with ethanol and ether. The aim of this study was to determine the most suitable extraction procedure in order to obtain extract with the highest antimicrobial potential. The results of well diffusion method indicate that raspberry juice and ethanol extract of raspberry pomace have shown higher antimicrobial potential in comparison to ether extract.

Interpretation, validation and segmentation of preference mapping models

In this paper we discuss an extension to preference mapping of the method proposed in [Endrizzi, I., Menichelli, E., Johansen, S. B., Olsen, N. V., & Næs, T. (2011). Handling of individual differences in rating-based conjoint analysis. Food Quality and Preference, 22, 241–254 ] for accommodating both population averages and individual differences in the same model. The method, based on average estimates and residuals, is a combination of ANOVA, PCA and PLS-DA, which are well-known techniques that can be run in almost all statistical software packages. Main attention is given to the relation between the double-centred residual matrix which highlights differences between consumers in their relative position as compared to the average consumer values and the standard centring in preference mapping. This approach has been found particularly useful for highlighting differences in preference pattern among the consumers. Furthermore, the interpretation and the segmentation, that is here taking place based on differences in acceptance pattern, are graphically oriented. In addition, some possible alternatives to the generally used validation method in PCA are suggested. The approach is then illustrated using two data-sets from consumer studies of apple and raspberry juice, showing that when individual differences are analysed by the present method, interesting results regarding individual differences in response pattern are detected.

Production of GABA (gamma amino butyric acid) by Lactic Acid Bacteria

Gamma-amino butyric acid (GABA) is a kind of pharmacological and biological component and its application is wide and useful in Korea specially, becoming aging society in the near feature. GABA is request special dose for the purposed biological effect but the production of concentrated GABA is very difficult due to low concentration of glutamic acid existed in the fermentation broth. To increase GABA concentrate using fermentation technology, high content of glutamic acid is required. For this reason, various strains which have the glutamic acid decarboxylase (GAD) and can convert glutamic acid to GABA, were isolated from various fermented foods. Most of GABA producing strains are lactic acid bacteria isolated from kimchi, especially added monosodium glutamate (MSG) as a taste enhancer. Optimizing the formulation of culture media and the culture condition, GABA conversion yield and amounts were increased. Finally GABA concentration of fermentation broth in batch or fed batch fermentation reached 660 mM or 1000 mM, respectively. Furthermore formulation of culture media for GABA production developed commercially. Many studies about GABA-rich product have been continued, so GABA-rich kimchi, cheese, yogurt, black raspberry juice and tomato juices has been also developed. In Korea many biological effects of GABA are evaluated recently and GABA will be expected to be used in multipurpose.

Clarification of red raspberry juice using microfiltration with gas backwashing: A viable strategy to maximize permeate flux and minimize a loss of anthocyanins

Red raspberry (Rubus idaeus) juice was produced by maceration of raspberry pulp at 50°C for 2h using 400mgkg−1 Klerzyme®150 enzymatic pectolitic preparation followed by raw juice clarification with gelatin and bentonite or cross-flow membrane filtration. A minimal loss of anthocyanins from 630 to 540mgl−1 was obtained when the juice was clarified using a ceramic multichannel microfilter (MF) with a pore size of 0.2μm. A light transmission at 625nm in MF permeate was above 85% and the residual pectin (900mgl−1) was completely removed. During ultrafiltration through ceramic or polysulfone membranes with a molecular weight cut-off of 30–300kDa, the content of anthocyanins was reduced to 220–370mgl−1, but a light transmission at 625nm was as high as 96%. The permeate flux in MF was maintained at high values above 170lm−2h−1 at 3bar for more than 2h by backwashing the membrane with a compressed air every 6min for 1min. The cake compression at high pressures was avoided by short filtration times between backwashing.

A comparative study on different concentration methods of extracts obtained from two raspberries (Rubus idaeus L.) cultivars: evaluation of anthocyanins and phenolics contents and antioxidant activity

SummaryThe effects of conventional (CV) and microwave (MW) heating on total soluble solid (TSS) content, total anthocyanin content (TAC), total phenolic content (TPC) and antioxidant activity of raspberry juice obtained from two cultivars of Amol (AM) and Siyahkal (SK) were scrutinised. Antioxidant activity of the juices was measured by 2,2 diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging capacity and expressed as EC50 value. In the both methods, the concentration rate constant for the juices was significantly decreased by increasing operational pressure from 12 to 100 kPa (P &lt; 0.05). A first‐order reaction kinetic model was successfully fitted for the degradation of monomeric anthocyanins at all operating pressures. The results also showed that thermal treatment of MW compared CV in both SK and AM cultivars caused a lower decrease in the TAC, TPC and antioxidant activity. Moreover, the changes in trend of the antioxidant activities due to the thermal treatment were positively correlated with the TPC (r = 0.74, P &lt; 0.05) and TAC (r = 0.61, P &lt; 0.05).

Juice, Pulp and Seeds Fractionated from Dry Climate Primocane Raspberry Cultivars (Rubus idaeus) Have Significantly Different Antioxidant Capacity, Anthocyanin Content and Color

Raspberries contain flavonoid antioxidants whose relative concentrations may vary between the juice, pulp, and seed fractions. Oxygen radical absorbance capacity (ORAC), total anthocyanin content, and berry color were determined for six cultivars of primocane raspberries grown in a dry climate (Utah, USA). Significant ORAC differences were found between juice (18.4 ± 0.39μmol TE/g), pulp (24.45 ± 0.43), and seeds (273.27 ± 11.15) with all Utah cultivars combined. A significantly higher concentration of anthocyanins was present in Utah raspberry juice (20.86 ± 0.35mg cyanidin-3-glucoside eq./100g), compared to pulp (13.96 ± 0.35). Anthocyanin content of juice and pulp were significantly positively correlated with dark color (L*). This is the first report of fractional differences in dry climate raspberries, and has implications for the juice and supplement industries.

Concentration of raspberry (Rubus idaeusL.) juice using membrane processes

Concentration of raspberry (Rubus idaeus L.) juice by combination of membrane processes was investigated. The pre-treatment steps were crushing, enzyme treatment, pressing and clarification by microfiltration (MF). Ceramic tube MF membrane was used at low pressure and temperature (3.9 bar and 30 °C).Nanofiltration (NF) and reverse osmosis (RO) process with flatsheet membranes was studied to pre-concentrate the clarified and sterilized raspberry juice. The NF experiments were carried out at different flow-rates (400 l h−1 and 600 l h−1). Any significant effect of flow-rate was not experienced. Both pre-concentration processes were used at low temperature (30 °C) for a mild concentration of raspberry juice. For further concentration osmotic distillation (OD) was applied. The initial total soluble solid content of the raspberry juice was 8–10 °Brix, the final concentrate of OD was 70–80 °Brix.The membrane-, fouling- and the polarization layer resistance were determined in case of micro-, nanofiltration and r...

Optimization of microencapsulation of probiotics in raspberry juice by spray drying

AimsProbiotics were microencapsulated in raspberry juice through spray drying. Methods & ResultsA combination of probiotics (Lactobacillus acidophilus NRRL B-4495 and Lactobacillus rhamnosus NRRL B-442) was chosen to offer high viability. Maltodextrin's role as a carbon source was also assessed for its prebiotic potential. Spray drying inlet temperature (°C), total solids: maltodextrin ratio, and inlet feed rate (mL/min) were fixed as independent variables while % recovery, % survival and color were the dependent outputs. Conclusions & SignificanceHigh temperatures during spray drying are detrimental to probiotics and can be circumvented by sub-lethal thermal shock (50 °C for L. acidophilus and 52.5 °C for L. rhamnosus). Increasing the microencapsulating material concentration increased the survival rate of the probiotics.Non-dairy probiotic foods are becoming popular as they do not pose problems of lactose intolerance while they offer an alternative.

Effect of some hydrocolloids blend on viscosity and sensory properties of raspberry juice-milk.

Raspberry juice-milk is an acidic dairy drink (ADD) including two main phases, milk phase (pH: 6.6-6.7) and raspberry juice phase (pH: 3.2 ± 0.1). Due to the low pH in this beverage, milk protein sedimentation is usual problem and therefore hydrocolloid is added as a stabilizer. Thus, in current study the influences of pectin, CMC and Kappa-carrageenan on the stability of the milk-raspberry juice drink and their blend synergistic effect were investigated. For this purpose milk-raspberry juice drink samples were prepared using pure pectin, CMC and Kappa-carrageenan at concentrations of 0.2%, 0.3% and 0.35% respectively. Blends of pectin and Carboxymethylcellulose (ratios of 25:75, 33.4:66.6 and 34.3:65.7) at concentrations of 0.2%, 0.3% and 0.35%, were added during a certain process. Moreover, the stabilization mechanisms were studied using apparent viscosity and sedimentation percent measurements. Based on the findings of the present study, the best fitted samples were the ones containing the blends of pectin and Carboxymethylcellulose which were more stable and viscose than samples including pure Carboxymethylcellulose (P < 0.05). Kappa-carrageenan can not prevent casein agglomeration in raspberry juice-milk individually, but in the presence of CMC or CMC and pectin it produces a stable drink. In general, with utilizing synergistic effect of gum blend we can use lower gum concentration and decrease cost during manufacture.

Effect of mixing time, freeze-drying and baking on phenolics, anthocyanins and antioxidant capacity of raspberry juice during processing of muffins

Consumption of baked products constitutes an important part of a daily breakfast considering that people are continually grabbing meals on the go. Among baked products, muffins rank third in breakfast products and attract a broad range of consumers. Incorporation of red raspberry juice into muffins can add value to the product while preserving health benefits to the consumer. The purpose of this study was to evaluate the effect of mixing time, freeze-drying and baking on the phenolic and anthocyanin contents and antioxidant capacity of raspberry juice during the preparation of muffins. Freeze-drying of raspberry batters reduced their phenolic content and antioxidant capacity regardless of mixing time. Non-freeze-dried raspberry batter mixed for 5 min had the highest phenolic content (0.88 mg gallic acid equivalent g(-1) dry matter (DM)). Non-freeze-dried raspberry muffins had the highest antioxidant capacity (0.041 µmol Trolox equivalent g(-1) DM). Freeze-dried raspberry batters mixed for 5 and 10 min had the highest anthocyanin content (0.065 mg cyanidin-3-glucoside g(-1) DM). Baking reduced the anthocyanin content of both non-freeze-dried and freeze-dried raspberry muffins. Despite the reduction in valuable compounds, muffin is a vehicle for the delivery of these compounds.