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1.
Fruit smoothie samples were thermally treated (P70  10 min) or high hydrostatic pressure (HHP) processed (450 MPa) with holding time of 1, 3 or 5 min and antioxidant activity, phenolic content and colour values (L*, a* and colour intensity) were determined. Significant reductions in antioxidant activity (p < 0.001) and phenolic content (p < 0.001) were observed at the applied pressure and a maximum treatment time of 5 min. Mean values for redness (a*) showed an increase (p < 0.001) in HHP processed smoothies compared to fresh. As expected, storage also had a significant effect on colour variables but the effect was more pronounced in high pressure treated samples stored for 30 days. Both colour and antioxidant activity were significantly affected by high pressure processing. Therefore, process optimisation of high pressure systems should be considered by processors prior to its adoption as a preservation technique in order to minimise the effect on the quality of fruit smoothie products.Industrial relevanceFruit smoothies have become popular with consumers and may significantly contribute to daily antioxidant intakes. Thermal processing has been shown to reduce the antioxidant activity of fruits, thus non-thermal methods of pasteurisation such as high hydrostatic pressure processing could help retain antioxidants in fruit smoothies offering a unique selling point for processors. The present study focussed on assessing the effect of thermal and high pressure processing on the antioxidant activity and phenolic content of fruit smoothies. Since decreases in levels of antioxidants were noted during long term storage it would appear that higher pressure treatments (> 450 MPa) might be required for better retention of antioxidant compounds in fruit smoothies.  相似文献   

2.
The aim of the study was to determine the performance of a sensory panel in evaluation of carrots by investigating the effect of training sessions on the reliability of the sensory attributes. A sensory panel (n = 10) was trained in profiling five carrot genotypes during a training session with seven sensory replications and 13 attributes. A significant effect of training on the sensory profile was determined for bitterness, green flavour and burning aftertaste, indicating that a learning process in judging these attributes was taking place. Terpene flavour, terpene aroma and burning aftertaste were the most reliable determined attributes and carrot flavour, soapiness flavour and nutty flavour were the least reliable attributes. The developed sensory profile was applied on 16 carrot types with a large variation in quality. Winter hardiness, carrot genotype and carrot colour formed distinct groups within the sensory profile, which indicates that the present sensory profile is relevant for assessing sensory quality of carrots. The winter hardy genotypes were characterised by having relatively high intensities in green aroma, carrot aroma, nutty flavour, carrot flavour and sweetness, while the reverse was true for the Nantes types and the coloured carrots with the red and white genotype as being the most extreme.  相似文献   

3.
The effects of salt (0% or 0.5% of NaCl) and umami compounds (0% or 0.3% of monosodium glutamate (MSG) + 0.15% of disodium salts of ribonucleotides) on odour and flavour attributes of beef broth model systems (BG) were studied at two serving temperatures (25 and 50 °C). Flavoured BG samples were prepared using 1-octen-3-ol (35 mg l?1) and 2,6-dimethylpyrazine (100 mg l?1) alone (BGO and BGD) or in combination (BGOD). A noticeable odour and flavour potentiator effect of NaCl on flavour intensities (overall, broth-like and saltiness in all samples; mushroom flavour in BGO and BGOD samples; nutty and cocoa flavour in BGD and BGOD samples), partly related to a “salting out” phenomenon, was found. Compared to 2,6-dimethylpyrazine, 1-octen-3-ol provided a less congruent flavour, which could explain the absence of a potentiator effect of umami compounds on mushroom flavour intensity. Cocoa and nutty flavour intensities increased with serving temperature in both BGD and BGOD model systems. However, mushroom odour and flavour increased in BGOD model systems but not in BGO samples, as a result of the likely enhancement effect displayed by the presence of 2,6-dimethylpyrazine. Salting-out phenomenon on particular aroma-active volatile compounds was established using sensory analysis. The potentiator flavour effect of MSG and NaCl was dependent on the characteristics of the model systems.  相似文献   

4.
The effect of reuterin, lactoperoxidase system (LPS) and lactoferrin (LF) combined with high hydrostatic pressure (HHP) on the characteristics of sliced cooked ham during 35 days at 4 and 10 °C were investigated. Reuterin and LPS inhibited the growth of total microorganisms during 35 days at 4 and 10 °C, whereas a regrowth at 10 °C was observed when HHP was applied. Combined treatments kept total viable counts below 1.5 log cfu/g after 35 days at 10 °C. Regarding the effect of treatments on colour of cooked ham, LPS alone or in combination with HHP slightly affected L*, a* and b* values, but these changes tended to attenuate during storage. Likely, slight differences were registered in shear strength values among control and treated cooked ham. The accumulation of volatile compounds was reduced in cooked ham treated with LPS and LF in combination with HHP, even under abuse temperature conditions (10 °C).Industrial relevanceLPS applied in combination with HHP was the most effective treatment at reducing the growth of total microorganisms in refrigerated cooked ham with minor changes in its characteristics. The antimicrobial activity of such combined treatment against food-borne pathogens, which has also been reported in RTE foods, points to its usefulness to assure a safe product of sensory characteristics similar to those of untreated cooked ham.  相似文献   

5.
《Food chemistry》1998,61(4):435-441
Catechin levels in green leaf, total theaflavins, brightness, thearubigins, colour, flavour index and sensory evaluation decrease with coarse plucking standard in clone 6/8. The sum of Group I volatile flavour compounds and C6 aldehydes and alcohols, in particular, increases with coarse plucking standard. The sum of Group II did not follow a particular pattern, but flavour index decreased with coarse plucking standards. The decrease in total theaflavin levels was due to the decrease in all the individual theaflavins. Although all the individual theaflavin levels decreased with coarse plucking standards, the decrease was greater in galloylated theaflavins, especially in theaflavin digallate, compared with simple theaflavin. Short fermentation times produced black teas with higher brightness and flavour index, but lower theaflavins, thearubigins and colour, irrespective of plucking standard. Total theaflavins reached a maximum after 90 min of fermentation, irrespective of the plucking standard, whereas ungalloylated theaflavin levels decreased with extended fermentation duration at all plucking standards, theaflavin-3-gallate and theaflavin-3, 3’-digallate levels increased, resulting in the increase in theaflavin digallate equivalent. Brightness and flavour index decreased while thearubigins, colour, and Groups I and II volatile flavour compound levels increased with long fermentation.  相似文献   

6.
Fruit smoothie samples were thermally (P70 > 10 min) or high hydrostatic pressure (HHP) processed (450 MPa/20 °C/5 min or 600 MPa/20 °C/10 min) and the total antioxidant capacity (TAC), levels of antioxidant groups [total phenols (TP), anthocyanins and ascorbic acid], instrumental colour, polyphenol oxidase (PPO) enzyme activity and dissolved oxygen were examined over a storage period of 10 h at 4 °C. Thermal processing of smoothies reduced (p < 0.001) TAC and TP values, ascorbic acid and L and a colour attributes (lightness and redness respectively) compared to fresh and HHP-450 processed samples. Conversely, it did result in complete inactivation of PPO enzyme, with no activity detected. Of the HHP treatments, HHP-450 samples had higher (p < 0.001) levels of total antioxidant, phenols and anthocyanin content than HHP-600 samples. However, the latter was more effective in reducing (p < 0.001) the endogenous enzyme activity of the smoothies. .Ascorbic acid content degraded over the storage for all smoothies. HHP-600 samples had high initial values, which declined slowly over storage, while thermal samples had the lowest initial value (0.5 h) that fell below detectable limits by 10 h. Despite these data, less pronounced effects were observed for storage. No significant effects were observed for total anthocyanin and phenolic contents as well as L and colour change (ΔE) variables. Overall, HHP processing of smoothies at moderate temperatures may be a suitable alternative to traditional thermal processing.  相似文献   

7.
Commercial samples of fresh and mature Halloumi cheeses made from ovine or bovine milk were studied in order to establish their chemical, microbiological and sensory characteristics. Significant differences were observed between the two types of Halloumi cheese both when fresh and mature. The free volatile fatty acid (FVFA) content of the cheeses increased with maturation from 483 to 1356 mg kg−1 for the ovine product, but lower values (380–1248 mg kg−1) were found in the bovine cheese. During maturation for 40 days, Enterococcus faecium, which dominated the microflora of fresh ovine cheese, was replaced by lactobacilli, including a new species, Lactobacillus cypricasei, which was not found in the bovine samples. Fewer than 100 cfu g−1 lactic acid bacteria (LAB) were present in the fresh bovine cheeses, but a microflora dominated by lactobacilli developed with time. Yeast counts in the mature ovine and bovine cheeses reached 2.3–2.8×105 cfu g−1 and, as some of the yeasts were proteolytic and/or lipolytic, it was assumed that they were having a positive impact of the flavour of the cheeses. The sensory panel distinguished significant differences in texture and flavour between the fresh and mature samples of both ovine and bovine cheeses and, overall, there was a significant preference for the ovine brand.  相似文献   

8.
The effect of a pre-cut heat treatment (100 °C/45 s) as an alternative decontamination treatment to chlorinated-water (200 ppm active chlorine/1 min, 5 °C) was evaluated in minimally processed carrot (shredded). The quality of shredded carrots was studied just after minimal processing and during storage at 5 °C (10 days) by evaluating microbial (total mesophilic aerobic, yeast and moulds and lactic acid bacteria counts), physical–chemical (soluble solids content, pH, titratable acidity, whiteness index), physiological (peroxidase activity and headspace analysis) and sensorial attributes (colour, fresh-like appearance, aroma and general acceptance). The relationships between sensory perception of undesired changes, microbial contamination threshold, physico-chemical and physiological indices were investigated and compared between heat-treated and control samples. The use of heat in pre-cut carrot proved to be more efficient than chlorinated-water concerning microbial control (threshold concentration of 7 Log10 cfu g? 1), providing an acceptable fresh-like quality product during 10 days of storage (5 °C), which corresponds to a 3-day shelf-life extension compared to control samples. Heat-treated shredded carrot showed lower respiratory and POD activities than chlorinated samples suggesting that the use of heat provides a metabolic activity lowering effect besides the microbial effect which could be important to shelf-life extension of the fresh-cut product.Industrial relevanceIn minimally processed vegetables, namely in shredded carrot, chlorine solutions have been widely used by the industry for sanitization purposes. However, reduced microbiological efficiency allied to sensorial changes and eventual formation of carcinogenic chlorinated compounds pointed out the need for alternative decontamination methodologies. Also, the evermore conscious consumers are demanding minimization of the potentially negative impact of food processing on human health and the environment. From the practical experience of a fresh-cut industry directly involved in the R&D research project which supported this study, the marketability of minimally processed shredded carrot is limited due to rapid microbial growth and colour loss (decrease of orange intensity and/or whitening of the shreds). As a result, a pilot-plant scale study was performed, evaluating quality attributes of shredded carrot processed according to a clean pre-cut alternative decontamination process.  相似文献   

9.
《Meat science》2009,81(4):1254-1263
Sensory analysis of meatballs was carried out to monitor the warmed-over flavour (WOF) development in cooked, cold-stored (at 4 °C for 0, 2 and 4 days) and reheated meatballs derived from M. longissimus dorsi (LD) and M. semimembranosus (SM) of pigs fed a standard diet supplemented with either 3% of rapeseed oil or 3% of palm oil. This was performed in combination with measurement of volatile compounds using a solid-state-based gas sensor array system (electronic nose) and gas chromatography/mass spectrometry together with measurement of thiobarbitoric acid reactive substances (TBARS). Subsequently, to elucidate the relations and predictability between the obtained data, the gas sensor responses were correlated with chemical (volatile and non-volatile secondary lipid oxidation products) and sensory data (flavour and odour attributes), using partial least squares regression modelling (PLSR). The TBARS, hexanal, pentanal, pentanol and nonanal all correlated to the sensory attributes associated to WOF formation. Moreover, the responses from eight of the MOS (metal oxide semiconductor) sensors within the electronic nose proved to be significantly related to WOF characteristics detected by both sensory and chemical analysis, while six of the MOSFET (metal oxide semiconductor field effect transistor) sensors were related to freshly cooked meat attributes determined by sensory analysis. The obtained results show the potential of the present gas sensor technology to monitor WOF formation in pork.  相似文献   

10.
11.
Food reformulation, either to reduce nutrient content or to enhance satiety, can negatively impact upon sensory characteristics and hedonic appeal, whilst altering satiety expectations. Within numerous food systems, perception of certain sensory attributes, known as satiety-relevant sensory cues, have been shown to play a role in food intake behaviour. Emulsions are a common food structure; their very nature encourages reformulation through structural design approaches. Manipulation of emulsion design has been shown to change perceptions of certain sensory attributes and hedonic appeal, but the role of emulsions in food intake behaviour is less clear. With previous research yet to identify emulsion designs which promote attributes that act as satiety-relevant sensory cues within emulsion based foods, this paper investigates the effect of oil droplet size (d4,3: 0.2–50 μm) and flavour type (Vanilla, Cream and No flavour) on sensory perception, hedonics and expected food intake behaviour. By identifying these attributes, this approach will allow the use of emulsion design approaches to promote the sensory characteristics that act as satiety-relevant sensory cues and/or are related to hedonic appeal. Male participants (n = 24) assessed the emulsions. Oil droplet size resulted in significant differences (P < 0.05) in ratings of Vanilla and Cream flavour intensity, Thickness, Smoothness, Creamy Mouthfeel, Creaminess, Liking, Expected Filling and Expected Hunger in 1 h’s time. Flavour type resulted in significant differences (P < 0.05) in ratings of Vanilla and Cream flavour intensity, Sweetness and Liking. The most substantial finding was that by decreasing oil droplet size, Creaminess perception significantly increased. This significantly increases hedonic appeal, in addition to increasing ratings of Expected Filling and decreased Expected Hunger in 1 h’s time, independently of energy content. If this finding is related to actual eating behaviour, a key target attribute will have been identified which can be manipulated through an emulsions droplet size, allowing the design of hedonically appropriate satiating foods.  相似文献   

12.
《Food chemistry》1998,61(3):293-300
This study reports the analytical and sensory analyses made on selected kiwifruit genotypes (Actinidia chinensis (Planch.) var. chinensis) produced from seeds of fruit gathered in the Guangxi region of the People’s Republic of China. The analytical measurements of some soluble sugars, such as glucose and fructose, and non-volatile acids, such as malic and ascorbic acid, were carried out using innovative analytical procedures based on fast and selective devices that require very little or no sample treatment. The multivariate techniques, Principal Component Analysis and Cluster Analysis, useful when many variables are involved, allowed the classification of kiwifruit genotypes according to sugar and non-volatile acid contents and sensory properties. Citric acid, the major organic acid, ranged from 0.8 to 1.8 g per 100 g of fresh weight and malic acid content was 0.1–0.5 g per 100 g of fresh weight. The levels of fructose and glucose (present in approximately equal amounts in most of the genotypes analysed), were higher than that of sucrose in almost all the genotypes. Ascorbic acid content in kiwifruit samples from genotypes of Actinidia chinensis (Planch.) var. chinensis was higher than the typical mean content in Actinidia chinensis var. deliciosa (A Chev) cv Hayward. Sensory assessment showed that total fruit aroma and flavour were the best discriminating attributes and were highly correlated with overall quality. No consistent correlation was found between overall quality and the sensory attributes of sweetness, juiciness and firmness.  相似文献   

13.
Concentrating cashew apple juice alters the beverage aroma and flavor, compromising consumer acceptability of the concentrated beverage. To understand the mechanisms involved in these changes, this research characterized the dynamics of the loss and emergence of volatile compounds during cashew apple juice concentration, reporting their impact on beverage sensory quality. Fresh cashew apple juice (10.3°Brix) was concentrated in a thermal-siphon type evaporator operating in a closed system. Five samples were taken throughout the concentration process with the following soluble solids contents: 11.8°Brix, 14.9°Brix, 20.2°Brix, 29.6°Brix and 42.1°Brix. Trained judges rated the aroma note intensities, described as “fresh cashew apple” and “cooked” as perceived in the fresh and concentrated beverages. The headspace volatiles of the six samples were identified and quantified by GC–MS. The results indicated the esters as the major component in the fresh juice (226.46 μg kg 1) representing 45.0% of the total mass of volatiles, followed by the terpenes (118.98 μg kg 1), acids (45.23 μg kg 1), aldehydes (39.10 μg kg 1), alcohols (18.91 μg kg 1), lactones (19.15 μg kg 1), hydrocarbons (18.02 μg kg 1) and ketones (11.05 μg kg 1). Predictive statistical models (R2 > 0.956, p  0.002) revealed that on reaching 14.9°Brix, the ester concentration declined more than 90%, the terpene content almost 100%, alcohols 85%, aldehydes 80% and hydrocarbons 90%. At 14.9°Brix, the intensity of “fresh cashew apple” aroma still predominated in the juice, but the panelists detected the presence of a weak “cooked” aroma. Concentration of the beverage to 20.2°Brix or above expressively increased the cooked aroma intensity and the concentration of hydrocarbons, alcohols and some aldehydes usually associated with off-flavors such as pentanal and decanal. This raises the possibility that some of these compounds might have been formed during juice processing. Juice with better sensory quality could possibly be obtained by concentrating the beverage to levels below 20.2°Brix, recovering the esters that evaporated off the juice until ~ 15°Brix is reached, and re-adding them to the juice concentrated.  相似文献   

14.
Differences between two age groups in texture and flavour perception, in food appreciation and in texture and olfactory sensitivity were investigated. Three experiments were conducted: ratings of texture and flavour attributes, ratings of pleasantness of (1) sweet vanilla waffles, (2) savoury cheese waffles by elderly (n = 22, 60–85 years) and young (n = 16, 18–35 years) subjects, and (3) tests measuring texture sensitivity (young and elderly) and olfactory sensitivity (elderly only). The elderly differed from the young in their perception of texture and flavour, but the observed texture flavour interaction effect was not different for the elderly and young. A decrease in the importance of flavour in food appreciation was observed for the elderly in the savoury but not in the sweet waffles. The young were more efficient in chewing and they were better in oral letter recognition test. Among the elderly, olfactory sensitivity influenced flavour intensity ratings, whereas poor texture sensitivity was not related to perception of sensory attributes.The present study does not support the hypothesis that a different rate in the decline of the different senses with age will inevitably lead to a different integrated product concept.  相似文献   

15.
The oxidative stability of cream cheese stored in thermoformed trays made of amorphous polyethylene terephtalate (A-PET)/polyethylene (PE), polystyrene (PS)/Ethylene-vinylalcohol copolymer (EVOH)/PE and Polypropylene (PP)/PE with different depth (25, 50 and 70 mm) and colour (black, white and transparent) was studied by sensory evaluation and gas chromatographic analysis of volatile compounds. The polymer combination had an important effect on sensory scores of both sunlight and acidulous flavour in cream cheese stored in the dark for 2, 4 and 6 months. Cream cheese stored in trays made of A-PET/PE had higher acidulous flavour and lower content of hexanal and 2-nonanone. Only small differences were observed between PS/EVOH/PE and PP/PE despite the great diversity of oxygen transmission rates. The drawing depth of the packages had no significant effect on oxidative stability of cream cheese, irrespective of storage in the dark or under illumination. The colour of the examined packaging material had a pronounced effect on photoxidative changes in cream cheese.  相似文献   

16.
The flavour perception of cheese results from complex sensory interactions between tastes and aromas. Using a model cheese solution, this study investigated perceived interactions between each of five basic tastes and a cheese aroma mixture containing ten volatile compounds commonly found in cheese. The five tastes – sucrose (sweetness), sodium chloride (NaCl) (saltiness), monosodium glutamate (MSG) (umami), lactic acid (sourness), and caffeine (bitterness) – were individually mixed with cheese aroma in water using a 5 taste level (0.2 log series) by 3 aroma level (0.5 log series) design. Aroma controls with no added taste were also included. This resulted in 18 samples for each single taste–aroma combination. An additional 18 samples were produced using a mixture of all 5 tastes with the 3 aroma levels. A panel of trained assessors (n = 10) evaluated cheese flavour intensity and taste intensity using 100 point line scales. Evaluation was carried out in duplicate, with samples grouped by taste type; 1 evaluation session per taste per replicate. Within type, order of presentation was balanced, and taste type order was randomised between replicates. Cheese flavour intensity was enhanced by sucrose and NaCl, while being suppressed by lactic acid. NaCl enhanced cheese flavour intensity the most at high aroma level, while lactic acid suppressed the most at low aroma level. When MSG level was increased, cheese flavour intensity was enhanced at both low and medium aroma levels, but was suppressed at the high aroma level. The greatest enhancement of cheese flavour intensity was found with the mixture of 5 tastes. Aroma significantly enhanced umami and bitterness, but did not enhance sweetness, saltiness, or sourness. This study showed that the perceived interaction between taste and cheese aroma depended on taste type and on the concentration levels of both taste type and aroma. The mixture of tastes was more effective at enhancing cheese flavour intensity than single tastes. This study provides knowledge that will underpin further study of taste–aroma interactions in a model cheese that aims to optimise cheese flavour intensity and character.  相似文献   

17.
In this research work, we aim to identify, quantify and compare the phytochemical such as vitamin C, carotenoid and chlorophyll pigments, phenolic compounds and intact glucosinolates, as well as the in vitro antioxidant activity and physical quality parameters (colour, firmness, moisture contents, weight/broccoli head and soluble solid contents) of Monaco and Parthenon broccoli cultivars. We found that the bioactive compounds were more abundant in Parthenon compared with Monaco. In fact, higher amount of chlorophylls (12.62 mg/100 g fresh weight), total phenolic compounds (147.15 mg chlorogenic acid equivalent/100 g fresh weight), and total intact glucosinolates (203.85 μmol of sinigrin equivalent/100 g fresh weight) were found in Parthenon. On the other hand, no significant differences were observed in terms of external quality parameters among the studied cultivars except in the colour and moisture contents.  相似文献   

18.
This study evaluated the effects of high hydrostatic pressure (HHP) on the microbial counts, physicochemical properties, bioactive compounds, and antioxidant capacity of jujube pulp. Additionally, this study compared the shelf life of jujube pulp following HHP (600 MPa/20 min) and thermal treatment (100 °C/10 min) during 40 days of storage at 4 °C and 15 °C. The microbial count of HHP-treated jujube pulp (≥ 400 MPa/20 min) was below the detection limit. Total soluble solids and total sugars were not significantly affected by HHP processing, and > 90% ascorbic acid was retained in HHP-treated samples. HHP slightly reduced pH and browning degree and increased total phenolic content, flavonoid content, and antioxidant capacity. HHP can be used as an alternative to thermal pasteurization of freshly squeezed jujube pulp.Industrial relevanceEffects of high hydrostatic pressure (HHP) processing and thermal treatment (TT) on microbiological quality, physicochemical properties, bioactive compounds and antioxidant activity in jujube pulp were investigated. Greater inhibition of microorganisms and better retention of ascorbic acid, total phenolics, flavonoid and antioxidant capacity were observed after HHP-treatment. The available data could be used to design the HHP parameters for high quality jujube juice. Further, this research would provide a useful method for preservation of jujube products and potential technical support for jujube commercial production.  相似文献   

19.
《LWT》2003,36(3):295-302
Spray-dried blood plasma (DBP) (10.9 g/100 g [w/w] nitrogen) was added to medium-protein biscuit flour (1.4 g/100 g N) during pasta manufacture. High-protein durum semolina (2.0 g/100 g N) was used to produce the control pasta. Sensory data indicated that the addition of DBP produced pasta with significantly better colour intensity and acceptability, aroma intensity, flavour intensity, textural strength, texture acceptability, aftertaste intensity, aftertaste acceptability, and overall acceptability. The DBP/biscuit flour formulation that gave the optimum balance between pasta protein content and organoleptic acceptability contained 2.2 g/100 g DBP. A higher content of DBP resulted in increased protein levels, but these pasta formulations were less acceptable organoleptically.  相似文献   

20.
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