High pressure processing of Australian navel orange juices: Sensory analysis and volatile flavor profiling

Navel orange juices subjected to high pressure processing (HPP) and temperature treatment (TT) were stored at 4 and 10 °C for up to 12 weeks to establish the shelf-life of such products. The processed juices and a control juice, stored at − 20 °C, were assessed by a trained sensory panel and a consumer acceptance panel at 0, 1, 2, 4, 8 and 12 weeks or until such time that the juices were considered unfit for consumption. Untreated juice stored at 4 °C was similarly assessed for up to 2 weeks and untreated juice stored at 10 °C was assessed for up to 1 week. The volatile components of corresponding juices were isolated by SPME and the extracts were analyzed by GC–MS. Twenty key aroma compounds were selected for quantification and these data were used to monitor the change in volatile content of the juices during storage. The study showed that the odor and flavor of the HPP juice was acceptable to consumers after storage for 12 weeks at temperatures up to 10 °C. However, only the TT juice stored at 4 °C was acceptable after the same length of storage.

Industrial relevance

Orange juice is a sensitive product subject to a high microbial load that can tolerate only moderate heat treatment without the destruction of the product’s delicate aroma and flavor characteristics. High pressure processing at moderate pressures and storage at refrigeration temperatures have been evaluated as means of maximizing microbial inactivation while maintaining consumer acceptability of the product. The sensory and analytical data presented demonstrate that high pressure processing with refrigeration can extend the shelf-life of orange juice while maintaining consumer acceptability.     

Changes in quality attributes of pulsed light and thermally treated mixed fruit beverages during refrigerated storage (4 °C) condition

The effect of batch pulsed light (PL) irradiation (3000 J cm⁻²) on the shelf-life of the beverage blend comprising apple ber (Indian jujube), carambola (star fruit), and black table grapes was investigated. The equivalent thermally treated beverage (90 °C|5 min) exhibited greater stability from microbial and enzymatic spoilage but retained 27% less antioxidants and 14% less vitamin C than PL-treated juice. Thermally and PL-treated blends possessed sensory scores of 5.8 and 7.2, respectively. The beverage's microbial shelf-life (population ≤ 6-log₁₀ cfu/mL) was extended to 45 days at 4 °C after the PL treatment. The PL exposure did not alter the pH and soluble solids during storage. The PL-treated juice, after 45 days, was placed on par with the freshly prepared juice by the sensory panel. The PL-treated juice preserved 61% more antioxidants, 38.8% more phenolics, and 68.2% more vitamin C than the thermally pasteurized beverage after 45 days of refrigerated storage.Industrial relevanceWhile the fruit processing industry demands microbial safety and enzymatic stability, today's consumer demands juices of high nutritional quality. This study utilizes under-explored fruits like apple ber (Indian jujube) and carambola (star fruit) to make a shelf-stable mixed fruit beverage. This study will help the industry understand the potential of PL treatment in accomplishing microbial safety, enzymatic stability, and nutritional quality, along with the utilization of under-explored fruits.     

Optimization of Fruit Punch Using Mixture Design

ABSTRACT:  A highly acceptable dehydrated fruit punch was developed with selected fruits, namely lemon, orange, and mango, using a mixture design and optimization technique. The fruit juices were freeze dried, powdered, and used in the reconstitution studies. Fruit punches were prepared according to the experimental design combinations (total 10) based on a mixture design and then subjected to sensory evaluation for acceptability. Response surfaces of sensory attributes were also generated as a function of fruit juices. Analysis of data revealed that the fruit punch prepared using 66% of mango, 33% of orange, and 1% of lemon had highly desirable sensory scores for color (6.00), body (5.92), sweetness (5.68), and pleasantness (5.94). The aroma pattern of individual as well as combinations of fruit juices were also analyzed by electronic nose. The electronic nose could discriminate the aroma patterns of individual as well as fruit juice combinations by mixture design. The results provide information on the sensory quality of best fruit punch formulations liked by the consumer panel based on lemon, orange, and mango.     

Study of chemical changes in pasteurised orange juice during shelf-life: A fingerprinting-kinetics evaluation of the volatile fraction

The current work used fingerprinting-kinetics for the first time to monitor shelf-life changes in a low-pH, pasteurised, shelf-stable product, more particular in orange juice. Orange juice samples were stored as a function of time at four different storage temperatures (20, 28, 35 and 42 °C). To obtain insight into chemical changes in the volatile food fraction, samples were fingerprinted with headspace GC–MS. The objectives of this work were twofold: (i) to identify major chemical changes of pasteurised orange juice during shelf-life and (ii) to study the kinetics of selected shelf-life compounds in the context of accelerated shelf-life testing (ASLT). At 20 °C, changes in terpenes and a decrease in aldehydes were observed. Oxides and sulphur compounds increased and esters decreased at increased storage temperatures (at 28 °C and above). Concerning ASLT, four volatile compounds had clear temperature and time dependent kinetics within the investigated temperature range.     

Improving the safety and shelf-life of orange and mango juices using Panax ginseng, malic acid and potassium sorbate

In this research, several plant compounds were in vitro evaluated against Salmonella enterica ser. Saintpaul and Escherichia coli O157:H7 through disc’s method. Among them Panax ginseng (PG) showed the highest antimicrobial activity in comparison to other natural antimicrobials. Combinations of PG (2?% v/v) with malic acid (MA) (0.5?% v/v) and/or potassium sorbate (PS) (0.05?% v/v) were made for evaluating their effects on S. Saintpaul and E. coli O157:H7 populations in sterile and fresh mango and orange juices stored at 5?°C. The best combination of antimicrobial compounds on native flora (during 21?days) as well as sensory attributes (0?day) of fresh juices were evaluated. The antimicrobial compounds added into mango and orange juices were more effective against S. Saintpaul than against E. coli O157:H7. The combination of PG (2?% v/v), MA (0.5?% v/v) and PS (0.05?% v/v) showed the highest antimicrobial effectiveness against both pathogenic microorganisms in both juices, in addition to a higher microbiological inhibition during storage (21?days). Sensory attributes such as aroma, color and taste were enhanced, but acidity was notably affected in both juices. In conclusion, the combination of PG, MA and PS could be an effective method in the food industry for ensuring the microbial safety and quality in mango and orange juices.     

Degradation of quality attributes of sweetened Julie and Ogbomoso mango juices during storage

Changes in the quality attributes of sweetened Julie and Ogbomoso mango juices were investigated. Sweetened mango juices were processed, bottled and stored at 25 °C for 12 weeks. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents were evaluated immediately after processing and subsequently at 2-week intervals. The L*, a* and b* (HunterLab) parameters were determined to evaluate colour changes due to non-enzymatic browning.Generally, the quality attributes of the sweetened mango juices decreased during storage. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents decreased during storage. After 12 weeks of storage, the percentage ascorbic acid loss of sweetened Julie and Ogbomoso mango juices was 16.25 and 16.67%, respectively. Browning index, chroma and b* values increased during storage. Colour changes in sweetened mango juices were mainly due to b* value and chroma.     

COLOR AND VITAMIN C CONTENT IN MANDARIN ORANGE JUICE AS AFFECTED BY PACKAGING MATERIAL AND STORAGE TEMPERATURE

Mandarin orange (Citrus reticulata) juice was packed in two different non-transparent cartons made of polyethylene, cardboard and (1) aluminum foil (Tetrapak ^® ) or (2) ethylene vinyl alcohol copolymers (Pure-pak ^® ) and was stored at 4C or room temperature (25  ±  3C). During the shelf life of these juices (35 days), changes in the headspace gas composition, vitamin C and CIEL*a*b* color coordinates were evaluated. In addition, a consumer panel evaluated the sensory color of the juices. Mandarin orange juices darkened and ascorbic acid content decreased with storage time. Type of carton and storage temperature played a predominant role in determining the final juice quality, with Tetrapak ^® carton providing the juice with the best quality (intense orange color and high vitamin C content and consumer preference) throughout their shelf life.

PRACTICAL APPLICATIONS

This study was a clear example of how research can help real food companies in selecting the right materials for their production lines. In this particular case, the results presented show how Tetrapak^® packaging led to a final mandarin orange juice of higher quality compared to Pure-pak^® packaging. Therefore, citrus processing companies have some scientific data comparing the behavior of these two types of non-transparent cartons. Besides, the companies manufacturing these cartons also have some information about their materials and can use it to improve them.     

Reaction pathways and factors influencing nonenzymatic browning in shelf-stable fruit juices during storage

The occurrence of nonenzymaticbrowning in fruit juices during storage is a major quality defect. It negatively affects consumer acceptance and consumption behavior and determines the shelf-life of these products. Although nonenzymatic browning of fruit juices has been the subject of research for a long time, the exact mechanism of the nonenzymatic browning reactions is not yet completely understood. This review paper aims to give an overview of the compounds and reactions playing a key role in nonenzymatic browning during the storage of fruit juices. The chemistry of the plausible reactions and their relative importance will be discussed. To better understand nonenzymatic browning, factors affecting these reactions will be reviewed and several strategies and methods to evaluate color changes and browning will be discussed. Nonenzymatic browning involves three main reactions: ascorbic acid degradation, acid-catalyzed sugar degradation, and Maillard-associated reactions. The most important NEB pathway depends on the matrix. Nonenzymatic browning is affected by many factors, such as the juice composition, the pH, the oxygen availability (packaging material), and the storage conditions. Nonenzymatic browning can thus be considered as a complex problem. To characterize color changes and browning and obtain insight into the browning mechanism of fruit juices, food scientists applied several approaches and strategies. These included the use of model systems with/without the addition of labeled compound and real systems as well as advanced analytical methods.     

Sensory and Microbial Quality of Irradiated Crab Meat Products

Low dose gamma irradiation has proved effective in reducing pathogenic and spoilage microorganisms in a variety of seafood products. However, little information is available on the effect of irradiation on the sensory quality and consumer acceptance of such products. We compared microbial and sensory quality of irradiated (2 kGy or less) crab products (white lump, claw, and fingers) through 14-days of ice-storage. Irradiation effectively reduced spoilage bacteria extending shelf-life by more than 3 days beyond control samples. During storage, fresh crab odor and flavor were similar for treated and control samples, while off-flavors and odors developed more rapidly in controls. Overall acceptability scores for irradiated crab samples were higher than for control samples throughout 14-days ice storage.     

IRON CONTENT, SENSORY EVALUATION, AND CONSUMER ACCEPTANCE OF FOOD COOKED IN IRON UTENSILS

The purpose of this study was to determine the effect of cooking food in iron utensils on the iron content, sensory quality, and consumer acceptance/ preference of the food. Hamburger patties and applesauce were cooked in iron and in glass utensils and were analyzed for iron content by atomic absorption spectrophotometry and evaluated by a trained sensory panel, by consumers, and for chroma, pH, and refractometer changes. Cooking hamburger patties and applesauce in iron utensils increased iron in the food, did not affect sensory quality or consumer acceptance/preference of hamburger patties, but affected the color and flavor and decreased consumer acceptance/preference for applesauce.     

Improving quality of fresh‐cut mango using polysaccharide‐based edible coatings

This study was aimed at evaluating the effect of coatings with alginate (AL), pectin (PE), carboxymethyl cellulose (CMC) or chitosan (CH) on microbial stability, physicochemical attributes, total phenolics and carotenoids content, antioxidant capacity and sensory properties of fresh‐cut mango during 14 days at 4 ± 1 °C. Coated fresh‐cut mango kept microbial counts below 6 logs CFU g^?1, being CH‐coated fresh‐cut mango those that exhibited the lowest microbial counts (1 log CFU g^?1) along entire storage. AL, PE and CMC coatings maintained yellow colour of fresh‐cut mango throughout storage. AL and CH coatings, which have different monomers in their chain, improved the content of antioxidant compounds in fresh‐cut mango as related to uncoated. AL‐coated fresh‐cut mangoes were the toughest, among those coated, during 14 days. The highest consumer acceptance was achieved in AL (90.2%) coated fresh‐cut mango. CH would be the most suitable coating to extend the quality of fresh‐cut mango throughout storage.     

Quality degradation kinetics of pasteurised and high pressure processed fresh Navel orange juice: Nutritional parameters and shelf life

A kinetic study of post processing quality loss was conducted after high pressure processing (600 MPa, 40 °C, 4 min) or thermal pasteurisation (80 °C, 60 s) of fresh Navel orange juice. Selection of processing conditions was mainly based on pectin methylesterase inactivation. Ascorbic acid loss, colour, viscosity and sensory characteristics were measured during storage at different isothermal conditions (0–30 °C). Increased shelf life (based on ascorbic acid retention) was achieved for high pressurised compared to thermally pasteurised juice, ranging from 49% (storage at 15 °C) to 112% (storage at 0 °C). Activation energy values for ascorbic acid loss were 68.5 and 53.1 kJ/mol, respectively, for high pressurised and thermally treated juice. High pressure processing resulted in better retention of flavour of untreated juice and superior sensory characteristics compared to thermal pasteurisation. Colour change was linearly correlated to ascorbic acid loss for both types of processing. Slightly higher apparent viscosity values were determined for high pressurised juice.Industrial relevanceApplication of high hydrostatic pressure on orange juice industry. Fresh orange juice is a product of high commercial and nutritional value due to its rich vitamin C content and its desired sensory characteristics. High Hydrostatic Pressure (HHP) is an alternative non-thermal technology that has been proposed for application on orange juice. Such a treatment denaturates enzymes and eliminates microorganisms responsible for spoilage of orange juice without detrimental effects on the sensory and nutritional quality of juice. The effect of HHP on the stability of fresh orange juice has been studied by different research groups, while orange juices processed with the new technology have already been commercially available in Japan, U.S.A., Mexico and Europe. However, a systematic kinetic approach of the effect of HHP on different quality indexes (not only microbial spoilage) immediately after processing, as well as during a long term storage of the processed orange juice is needed, in order to achieve an optimal process design and a successful application of the new technology in orange juice industry. Such kinetic data for parameters related to the quality and nutritional value of fresh orange juice were gathered in the present work providing therefore industry with useful information for the HHP stabilization of orange juice and the production of a high quality product. Due to the great benefits of HHP compared to the conventional pasteurization that emerged from this work regarding the quality, shelf life and nutritional characteristics of fresh orange juice, HHP technology is an advantageous alternative process for high valued products like orange juice.     

Sensory changes in liquid milk during storage and the effect on consumer acceptance

The acceptance of dairy products by consumers is generally determined by the product's sensory characteristics. These characteristics are a result of various changes in the product and the surrounding environment. The purpose of this paper is to report on a detailed sensory and consumer investigation of the changes in liquid skimmed milk held over an eight day period at three different storage temperatures: 1°C, 5°C and 10°C. Results of an objective sensory profile and subsequent data analysis revealed that sensory changes in milk could be described and quantified, clearly indicating the product's shelf-life profile. Product acceptability as perceived by consumers was undertaken on a subset of samples, illustrating the points at which consumers noticed significant changes. Overall, as the samples went through their shelf-life at the higher temperature they became less acceptable. The final part of the experiment used statistical modelling procedures to interpret and understand the data. As expected, it was shown that products became more stale during storage, and that temperature of storage affected the rate of staling, this being most marked at the higher temperature. Staleness was related to the attributes vegetable, sour, cardboard, chalky and mouthcoating.     

Production of Shelf-Stable Ranch Dressing Using High-Pressure Processing

ABSTRACT:  High-pressure processing (HPP) can reduce or eliminate microorganisms of concern in food without deteriorating product quality; however, quality benefits must justify the substantial capital investment for the utilization of this technology. HPP is particularly a beneficial preservation technology for products damaged by thermal treatments or when product quality could be improved by reformulation to raise pH or eliminate chemical preservatives. The primary objectives of this study were to determine the efficacy of HPP to protect premium ranch dressing (pH 4.4) from microbial spoilage and to assess changes in physical, chemical, and sensory attributes throughout the product's shelf life. In inoculated-packages studies, the efficacy of HPP was measured against ranch dressing spoilage organisms: Pediococcus acidilactici, Lactobacillus brevis, and Torulaspora delbrueckii . HPP treatment (600 MPa, 3 min) decreased population of P. acidilactici , the most pressure-resistant spoilage organism tested, by ≥ 6.4 log CFU/g. During a shelf-life study of edible product, treating ranch dressing at 600 MPa for 5 min effectively prevented microbial spoilage throughout the storage period (26 wk at 4 and 26 °C). The pH and emulsion stability of ranch dressing were not adversely influenced by HPP. Extended storage of HPP product for 16 to 26 wk at 26 °C resulted in a decrease in consumer acceptance and significant changes in color and organic acid profile (specifically, increased pyroglutamic acid). These changes were consistent with those expected during extended storage of commercially available products. HPP may be used to produce premium ranch dressing, with defined shelf-life and storage conditions, without significantly changing product attributes.     

Relationships between colour parameters,phenolic content and sensory changes of processed blueberry,elderberry and blackcurrant commercial juices

There is an increased interest in the consumption of fruits containing high phenolic concentrations such as berry fruits. Attractive colour of berries plays a vital role for consumer acceptance. The aim of this work was to evaluate colour parameters (a*, b*, L*), phenolic content and sensory changes of blueberry, elderberry and blackcurrant (BC) pasteurised commercial juices during accelerate storage. Initial phenolic concentration was 3.21, 10.06, 10.72 g GAE L^?1 for blueberry, elderberry and BC, respectively. Moreover, phenolic concentration of all juices decreased by approximately 40% throughout the first 30 days. Blueberry exhibited a substantial decrease in a* (40%) in the first 30 days, while elderberry presented a gradual decrease and BC only presented a slight decrease (7%) at the end of storage. Colour preferences decreased when storage time increased. However, when consumers were informed that ‘the juices are a rich source of phenolics, which contribute to reducing risk of suffering chronic diseases’, a high level of purchase intention was obtained.     

Effect of clouding agents on the quality of apple juice during storage

Apple pomace, (AP) was subjected to evaluation as potential source of clouding and antiradical agent in cloudy apple juice (CAJ). The evaluation was carried out in comparison with three hydrocolloids, namely sodium carboxymethyl cellulose (CMC), xanthan (XA), and pectin (P). The quality parameters of cloudy apple juice such as cloud stability, viscosity, phenolic content, sensory evaluation and antioxidant activity had been studied since these parameters control the consumer acceptance of that product. All the analyses were carried out for fresh and treated juices after storage at 4 and 25 °C for two weeks. The cloud stability of juices added decreased quickly and remained more stable than the untreated treatment. However, the hydrocolloids showed significant (P < 0.05) increase in viscosity, they exhibited deterioration in sensory attributes. The results indicated a good correlation between phenolic degradation and the radical scavenging activities.