COMPARATIVE CONSUMER AND PHYSICOCHEMICAL ANALYSIS OF DEL MONTE HAWAI`I GOLD AND SMOOTH CAYENNE PINEAPPLE CULTIVARS

Del Monte Hawai`i Gold (Del Monte Fresh Produce [Hawai`i], Inc., Honolulu, HI), an experimental hybrid clone of Smooth Cayenne pineapple, was found to have significantly higher (P < 0.0001) pH, °Brix/acid ratio, yellow color, total carotenoid content and vitamin C than Smooth Cayenne, while the titratable acidity of Smooth Cayenne was significantly higher (P < 0.0001). Hawai`i consumers also significantly liked and preferred Del Monte Hawai`i Gold more than Smooth Cayenne pineapples when presented in three different forms: whole, unpeeled pineapple, pineapple spears and single‐strength juice. Results suggest that Del Monte Hawai`i Gold can surpass Smooth Cayenne as the market standard for fresh pineapples and for single‐strength pineapple juice.     

Freezing Rate and Frozen Storage Effects on Color and Sensory Characteristics of Pineapple Fruit Slices

This study was carried out to evaluate the influence of freezing process (cold room –18°C and air-blast freezer –50°C) and frozen storage (–18°C for 0 to 12 mo) on color and sensory quality of pineapple fruit slices (Smooth Cayenne and Red Spanish cultivars). L, –a and +b color parameters showed differences (P ≦ 0.05) with cultivar, but not with freezing rate. No differences (P ≥ 0.05) were found in sensory analysis (color and appearance) between the cultivars, frozen at different rates, compared to fresh product, or after 1 yr frozen storage. The two cultivars are suitable for freezing.     

Effect of freezing rate and frozen storage on the texture and sensory analysis of two pineapple fruit cultivars

The effects of freezing rate (in a cold room at –18°C and in an air-blast freezer at –50°C) and frozen storage (at –18°C for 0–12 months) on texture and the sensory quality of pineapple fruit slices of Smooth Cayenne and Red Spanish cultivars were examined. The texture of pineapple fruit slices was evaluated by sensory and instrumental measurements. Sensory texture was highly (P0.05) and positively correlated with overall fruit acceptability and appearance and negatively correlated with flavour in the two cultivars studied. Sensory analysis showed no significant differences (P0.05) in the appearance, colour, odour, texture, flavour and overall acceptability between the two varieties studied when frozen at different rates, as compared to the fresh product and after 1 year of frozen storage at –18°C. The two cultivars are suitable for freezing.     

HPLC determination of organic acids in pineapple juices and nectars

HPLC organic acid profiles of pineapple fruit, its natural juice, juice concentrate, commercial juices and nectars were established. Other determinations were: pH and titratable acidity. We have found a citric acid/L-malic acid ratio close to 2 as an index of authenticity of pineapple products.

---

Bestimmung von organischen Säuren in Ananassaft und Nektar

Zusammenfassung Organische Säure-Profile wurden in Proben von Ananasfrüchten, frischen Ananassaft, Saftkonzentrat und Nektar erstellt. Andere Bestimmungen waren pH und titrierbare Säure. Es wird beobachtet, daß echte Ananas-Produkte eine Beziehung zwischen Citronensäure und L-Apfelsäure von 2:1 zeigen.

     

Flavanol Composition and Caffeine Content of Green Leaf as Quality Potential Indicators of Kenyan Black Teas

The flavanol composition and caffeine content of green tea leaf, black tea quality parameters of theaflavins, thearubigins, liquor brightness and total colour varied more among clones than with time of the year. In green leaf, either (-)epicatechin gallate or (-)epigallocatechin gallate was the dominant flavanol present. Regression analysis of tasters' preferences for black teas against green leaf chemical components showed positive and significant correlations for (-)epicatechin gallate (r = 0·498, P ⩽ 0·05 for taster A; r = 0·665, P ⩽ 0·01 for taster B, and r = 0·678, P ⩽ 0·01 for both tasters' overall ranking), (-)epigallocatechin gallate (r = 0·513, P ⩽ 0·05 for taster B; r = 0·532, P ⩽ 0·05 for both tasters' overall ranking and caffeine (r = 0·523, P ⩽ 0·05 for taster A; r = 0·657, P ⩽ 0·01 for taster B; and r = 0·686, P ⩽ 0·01 for both tasters' overall ranking). Similar regressions against black tea theaflavins, thearubigin content, liquor brightness and total colour were not significant. The results suggest that the green leaf chemical components, (-)epicatechin gallate, (-)epigallocatechin gallate and caffeine could be used as quality potential indicators during clonal selection and propagation. © 1997 SCI.     

山楂后贮条件对山楂酒品质和风味的影响

该实验将鲜山楂密封贮藏于15 ℃、25 ℃和35 ℃,研究贮藏温度和时间对山楂酒品质和风味成分的影响。结果表明,相同贮藏时间条件下,随贮藏温度在15～35 ℃范围内升高,山楂酒pH值上升,总酸、柠檬酸和L-苹果酸含量降低,酯类含量升高。25 ℃条件下贮藏5 d,山楂酒pH值上升0.08,总酸、柠檬酸和L-苹果酸含量分别降低1.39 g/L、822.03 mg/L和154.83 mg/L,酯类物质含量升高49.7 mg/L;35 ℃条件下贮藏4 d,山楂酒pH值上升0.03,总酸、柠檬酸和L-苹果酸含量分别降低1.04 g/L、887.60 mg/L和164.88 mg/L,酯类物质含量升高25.8 mg/L。因此,25～35 ℃密封贮藏,可有效降低山楂酒中柠檬酸和L-苹果酸含量,升高酯类物质含量,改善山楂酒的风味与口感。     

Processing and consumer acceptance of fruit leather from the unfertilised floral parts of jackfruit

A fruit leather was developed from the unfertilised floral parts of jackfruit. The characteristics of the leather were as follows: moisture 12·26%, fat 0·26%, protein 2·85%, crude fibre 6·27%, ash 0·87%, pH 4·8, titratable acidity 0·0005 meq NaOH g⁻¹, vitamin C 0·023 mg ascorbic acid per 100 g, caloric value 440 kcal per 100 g and water activity 0·6. The colour was bright yellow. Microbial count of the leather was low throughout the storage period. The fruit leather was most stable when packaged in laminated aluminium foil (LAF) during storage. Sensory evaluation showed that samples were acceptable by the panelists. A market survey showed that the fruit leather was slightly better accepted by the consumer at large than laboratory sensory panelists, especially by male respondents and from ethnic Indians. However, more work is needed to further improve the new fruit leather. © 1997 SCI.     

Physicochemical characterization of special persimmon fruit beers using bohemian pilsner malt as a base

This study involved the production of special fruit ale beers with different concentrations (100:0%, 75:25%, 50:50% and 25:75% v /v) of barley malt and persimmon juice from the ‘Rojo Brillante’ variety. Fermentation took place under beer quality control parameters and the influence of persimmon juice on beer quality was investigated. Colour, turbidity, pH, titratable acidity, total soluble solids, sugars, organic acids, total phenolic compounds, antioxidant capacity and ethanol formation were determined during the fermentation process. These fruit beers, whose alcoholic contents were within the standards (3.6–5.63% v /v ethanol), were characterized by a normal acid pH (3.97–4.13) with citric and lactic acids the most abundant organic acids, a clear golden colour without turbidity [2.05–2.83 European Brewery Convention units], intermediate total phenolic compound values (283.0–327.1 mg GAE/L) and antioxidant activities between 1.65 and 5.78 mm TE/L. The persimmon beverage which contained 75% fruit juice was the most valued and preferred by the panelists followed by the 50:50% wort–persimmon beer. Copyright © 2017 The Institute of Brewing & Distilling     

Prediction of titratable acidity, malic acid, and citric acid in bayberry fruit by near-infrared spectroscopy

An experiment was conducted to simultaneously measure titratable acidity, malic acid, and citric acid of bayberry fruit in a nondestructive manner using near-infrared (NIR) transmittance spectroscopy and chemometrics. The sampling set included different cultivars that were obtainable from different areas in China. Calibration models using partial least squares (PLS) regression were developed based on GB 12293-90 of China and with high-performance liquid chromatography (HPLC) as reference methods. Different preprocessing methods and different wave bands were applied. The correlation coefficient of calibration (r_c), root-mean-square error of calibration (RMSEC), and root-mean-square error of prediction (RMSEP) of the best model for titratable acidity was 0.8959, 2.24, and 2.89 g/L, respectively, with the range of 10,000-5405 cm⁻¹. R_c, RMSEC, and RMSEP values for malic acid and citric acid were 0.6689, 0.32, 0.47 and 0.8970, 1.51, 2.12 g/L, respectively. The prediction accuracies could not be improved by using first and second derivative pretreatment methods. Due to the short time consumption and low monitoring cost, NIR spectroscopic technique has its potential for the rapid and nondestructive prediction of titratable acidity and citric acid in bayberry fruit in a temperature-controlled room, although the accuracy was not high.     

Peroxidase and polyphenol oxidase in long-term frozen stored papaya slices. Differences among hermaphrodite and female papaya fruits

The effects of freezing and frozen storage on hermaphrodite and female papayas (cv Sunrise, solo group) polyphenol oxidase (EC 1.10.3.1; PPO) and peroxidase (EC 1.11.1.7; POD) were evaluated. The freezing process produces a significant increase in both enzymatic activities (22–11%, PPO and 13%, POD) depending on the kind of papaya fruit. During frozen storage, the soluble PPO activity shows a continuous increase up to 9 months of storage only in hermaphrodite tissues. This same sample also showed a significant activation of soluble POD at 3 months of storage. Female frozen samples maintained a continuous decrease in soluble POD activity during storage, while PPO activity showed some increase up to 12 months. Isoenzyme pattern of PPO in freshly frozen papaya tissues showed an intensification of the most cationic forms, D and E (R_f=0·55 and R_f=0·64, respectively) and a disappearance of band B (R_f=0·28). This band B was not regenerated during frozen storage. However, female tissues only showed a continuous inactivation of bands D and E through storage. POD isoenzyme pattern showed different changes depending on the kind of papaya fruit. In both frozen papayas a new isoenzyme (R_f=0·39) form appeared at three months of storage. From this date, hermaphrodite frozen samples lost this isoenzyme together with original the most anionic POD form (R_f=0·58), increasing the intensity of the only remaining form (R_f=0·24). © 1998 SCI.     

FT-NIR spectroscopy for the quality characterization of apricots (Prunus armeniaca L.)

Abstract: The nondestructive assessment of apricot fruit quality (Bora cultivar) was carried out by means of FT-NIR reflectance spectroscopy in the wavenumber range 12000 to 4000 cm⁻¹. Samples were harvested at four different ripening stages and scanned by a fiber optical probe immediately after harvesting and after a storage of 3 d (2 d at 4 °C and 1 d at 18 °C); the flesh firmness (FF), the soluble solids content (SSC), the acidity (A), and the titratable acidity (malic and citric acids) were then measured by destructive methods. Soft independent modeling of class analogy (SIMCA) analysis was used to classify spectra according to the ripening stage and the storage: partial least squares regression (PLS) models to predict FF, SSC, A, and the titratable acidity were also set-up for both just harvested and stored apricots. Spectral pretreatments and wavenumber selections were conducted on the basis of explorative principal component analysis (PCA). Apricot spectra were correctly classified in the right class with a mean classification rate of 87% (range: 80% to 100%). Test set validations of PLS models showed R² values up to 0.620, 0.863, 0.842, and 0.369 for FF, SSC, A, and the titratable acidity, respectively. The best models were obtained for the SSC and A and are suitable for rough screening; a lower power prediction emerged for the other maturity indices and the relative predictive models are not recommended. Practical Application : The results of the study could be used as a tool for the assessment of the ripening stage during the harvest and the quality during the postharvest storage of apricot fruits.     

Development of a multispectral imaging system for online quality assessment of pomegranate fruit

The objective of this study was to develop a prototype multispectral imaging system for online quality assessment on pomegranate fruit. At first, a visible/near infrared spectroscopy (400–1100 nm) was tested for non-destructive determination of total soluble solids, titratable acidity, and pH. The spectral data were analyzed using the partial least square analysis. Then to establish consistent multispectral imaging system, the highest absolute values of β-coeffcients correspond to wavelengths from the best partial least square calibration model were selected and used for identifying the optimal wavelengths. Consequently, a multispectral imaging system was developed based on the effective wavelengths 700, 800, 900, and 1000 nm. The performance of the developed multispectral imaging system was evaluated by multiple linear regression models. The multiple linear regression model predict total soluble solids with r = 0.97, root mean square error of calibration = 0.21°Brix, and ratio performance deviation = 6.7 °Brix. Also, the results showed that the models had good predictive ability for pH and titratable acidity. Results showed that the developed multispectral imaging system based on the optimal wavelengths could be used for online quality assessment of pomegranate fruit.     

Enzymes associated with blackheart development in pineapple fruit

The involvement of browning enzymes, polyphenoloxidase (PPO), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) in blackheart development was investigated in pineapple fruit (Ananas comosus, Smooth Cayenne) following low temperature storage. An increase in PPO activity was related to the incidence of blackheart symptoms, both temporally and spatially. Fruit maturity significantly affected blackheart susceptibility; immature and over-mature fruits developed less blackheart injury than mature fruit. The effect of maturity on blackheart susceptibility was highly correlated to the response of PPO activity to chilling. POD showed no significant change after chilling. Enhanced PAL activity was observed during chilling at 6, 13 and 18 °C. Chilling (6, 13 and 18 °C) also inhibited the increase of ascorbate peroxidase activity observed in the fruit stored continuously at 25 °C, but had less effect on catalase activity. The results indicate that the development of blackheart symptoms in pineapple fruit results from the disturbance of a number of metabolic processes that occur at sub-ambient temperatures.     

Chemical,antioxidant and sensory properties of tomato‐watermelon‐pineapple blends,and changes in their total antioxidant capacity during storage

A conductometric analysis of the effect of condensate of peroxides generated during lipid oxidation in an accelerated stability test was adapted to test the hypothesis that total antioxidant capacity of tomato products would sometimes increase during processing and in storage. Tomato pulp blends made from a mixture of tomato (Lycopersicon esculentum var Roma VF), watermelon (Citrullus vulgaris var Babylack) and pineapple (Ananas comosus var Smooth cayennes) were analysed for basic quality profiles of dry matter, Brix, titratable acidity (TTA) and pH, total reducing sugars, Component antioxidants phytochemicals and total antioxidant capacity. The lowest sensory score (overall impression) of 4.80 ± 2.59 was recorded for tomato juice while, blend TWP 111p had highest score of 6.20 ± 1.99. There was significant difference (P < 0.05) in the basic quality profile of the pulp blends except for TTA values (0.37 ± 0.02 to 0.45 ± 0.05) and 2‐Furfurals (2.47 ± 0.03 to 2.71 ± 0.01). The fresh blend of 50% tomato, 25% watermelon and 25% pineapple had the highest total antioxidant capacity of 3.69 ± 0.52 mg 100 mL^?1 catechin equivalent. The total antioxidant capacity of the stored pulp increased from 2.95 ± 0.13 to 6.22 ± 0.32 mg 100 mL^?1 catechin equivalent in pasteurised TWP 211p blend by 60 days when stored at 40 °C. Total antioxidant status of tomato‐based fruit mix increased during the first 80 days.     

Quality maintenance of minimally processed Chinese cabbage with low temperature and citric acid dip

Chinese cabbage (Brassica campestris L pekinensis group) was minimally processed using best preparation techniques and stored at 0 and at 5°C with and without dips in either citric acid, calcium chloride or ascorbic acid, all at 10 g litre⁻¹. The visual quality, degree of chilling injury, pH and taste were evaluated. The most deleterious effects on quality were produced by black speck (gomasho) and browning. Citric acid inhibited the development of black speck and extended storage life from 10 days of the control to 14 days at 5°C. At 0°C the storage life was not extended by any dip, but citric acid improved quality by reducing black speck. Minimally processed Chinese cabbage treated with citric acid showed only a slight reduction of pH from 6·3 of the control to 6·1 (P⩽0·05) and taste was not significantly affected (P>0·05). Microbial spoilage was not apparent during storage at 0°C for 35 days and 5°C for 21 days under any treatment. © 1997 SCI.     

Effects of post-harvest handling on quality attributes of tomatoes in the Nigerian marketing system

Changes in ascorbic acid and other quality attributes of fresh ripe tomatoes transported from the production areas in northern Nigeria to an urban wholesale market in south-western Nigeria were investigated. Reduced ascorbic acid concentration was lower, by as much as 35%, and dehydroascorbic acid concentration higher in damaged tomatoes relative to the undamaged control. Damaged tomatoes had a higher pH but lower total solids, soluble solids and titratable acidity than the undamaged fruits. pH and titratable acidity, as per cent citric acid, ranged from 4·06 and 0·453, respectively for undamaged tomatoes to 4·34 and 0·330, respectively for fruits with signs of bacterial and fungal rots. Total solids and soluble solids ranged from 6·12% and 5·32%, respectively for undamaged fruits to 5·39% and 4·34%, respectively for bruised tomatoes.     

Changes in chemical composition of coconut (Cocos nucifera) water during maturation of the fruit

Changes in chemical composition of coconut (Cocos nucifera) water, including total and soluble solids, titratable acidity (as citric acid), turbidity, ash, lipids and sugars, were investigated in four varieties of coconuts at four stages of maturity of the fruit. The most significant change was observed in the volume of nut water, which increased during development from 233 to 504 ml, with the greatest quantity found at 9 months. Fat, protein, soluble solids, acidity and turbidity also increased steadily with maturity, while pH and ash showed variation throughout maturation. The interaction of variety and stage of maturity of the fruit appeared to have a significant effect on the chemical composition of the coconut water. Copyright © 2004 Society of Chemical Industry     

Antifungal activity of chitosan and its application to control post‐harvest quality and fungal rotting of Tankan citrus fruit (Citrus tankan Hayata)

In this study, the antifungal activity of chitosan A (MW = 92.1 kDa) and B (MW = 357.3 kDa), with 94.2% N‐deacetylation were examined at various concentrations against fungi including Penicillium digitatum, Penicillium italicum, Botrydiplodia lecanidion and Botrytis cinerea. The effectiveness of these chitosans to control the post‐harvest quality of Tankan fruit, a popular sub‐tropical citrus fruit, was investigated. It was found that chitosan, depending on type and concentration, caused 25.0–90.5% growth inhibition on test organisms after 5 days of cultivation at 24 °C. Chitosan treatment significantly reduced (P < 0.05) the percentage decay of Tankan fruit during storage at 24 °C. After 42 days of storage at 13 °C, chitosan‐coated Tankan fruits were firmer, exhibited less decay and weight loss, and showed higher titratable acidity, ascorbic acid, and total soluble solids than the control fruit. Weight loss of Tankan fruits decreased as the concentration of chitosan was increased. On the other hand, chitosan A, regardless of concentration tested, was found to be more effective in retaining the firmness, titratable acidity and water content, total solid content and ascorbic acid content of Tankan fruits than chitosan B. Copyright © 2006 Society of Chemical Industry     

Forced‐air precooling treatment enhanced antioxidant capacities of apricots

Effects of forced‐air precooling on fruit quality and antioxidant system of apricot were evaluated in this study. Apricots were forced‐air precooled for 24 hr at 0°C, and then stored at 0°C for up to 20 days. Results showed that precooling treatment slowed down a decrease of titratable acidity (TA) and total soluble solids (TSS) during storage period, whereas it had no effect on pH and L* value. On the 15th day of storage, associated with higher flavonoids content, precooled fruit had 73.6% higher DPPH and 183% higher ABTS radical‐scavenging activities than the control. In addition, the peak of ascorbate peroxidase (APX) was earlier, and H₂O₂ content was reduced by precooling treatment with respect to control. These results indicate that precooling treatment could maintain the quality of apricot by enhancing antioxidant activity.

Practical applications

Fruit with high antioxidants implies high nutritional value. In this study, we found forced air precooling induced an increase of antioxidant activity of apricots. Precooling treatment should be used to enhance the quality and nutritional value of apricots.     

Sensory and chemical characteristics of Canadian ice wines

Fifty‐one Canadian ice wines, representative of a range of varieties and vintages, were evaluated chemically and 20 wines further evaluated sensorally. Ice wines from British Columbia and Ontario were significantly different for a range of chemical and sensory attributes. British Columbia ice wines had higher titratable acidity, acetic acid and glucose, and lower colour and ethyl acetate content compared with those from Ontario. Apricot, raisin, honey and oak aromas were more pronounced in Ontario ice wines, while British Columbia ice wines had higher intensities of pineapple and oxidized aromas. Riesling ice wines had higher titratable acidity and glucose and lower pH and A₄₂₀ values compared with Vidal. Vintage effects were also found for pH, A₄₂₀, glucose, fructose, ethanol and ethyl acetate. Copyright © 2004 Society of Chemical Industry