Effects of tangential microfiltration and pasteurisation on the rheological,microbiological, physico‐chemical and sensory characteristics of sugar cane juice

The aim of this study was to determine the physico‐chemical, microbiological, rheological and sensory characteristics of sugar cane juice with passion fruit pulp (5% w/w) added and which had been submitted to microfiltration and pasteurisation (90 °C/30 s; 95 °C/30 s) processes. The results showed that the juices obtained after the microfiltration and pasteurisation processes had low microbial counts. The microfiltered juice showed a reduction in the soluble solids, acidity and vitamin C content (P = 0.05), while the pasteurised juice showed no change in these parameters (P > 0.05) in relation to the natural sugar cane juice, with the exception of vitamin C, which was not detected after the thermal treatment. In relation to the rheological properties, Newtonian behaviour was observed for both microfiltered and pasteurised juices. The sensory tests on a hedonic scale showed good acceptance of both juices (microfiltered and pasteurised).     

Yield,characteristics and composition of banana juice extracted by the enzymatic and mechanical methods

A comparative study of the enzymatic and mechanical banana juice extraction methods and the respective juices produced was carried out using Kayinja bananas (ABB genotype) imported from Uganda. In the enzymatic extraction process, macerated ripe banana pulp was incubated with a commercial enzyme preparation (Pectinex Ultra SP‐L) at 50 °C for 2 h. In the mechanical extraction process the ripe banana pulp was mixed with stretched strips of polythene and worked with a dough mixer at room temperature for 20 min (on average) until the juice appeared. Significantly (p < 0.05) higher ‘pure’ juice yield (604 g kg^?1 pulp) was obtained with the enzymatic method than with the mechanical method (541 g kg^?1 pulp). However, adding water to the spent pulp from the mechanical process and extracting dilute juice improved the juice yield to 757 g kg^?1 pulp. The enzyme‐extracted juice had significantly (p < 0.05) higher soluble solids, titratable acidity, fructose, glucose, total nitrogen, density and mineral potassium. However, the mechanically extracted juice had significantly higher sucrose, pH and viscosity. Although the mechanical extraction process suffers from occasional juice extraction failures, it offers an opportunity to extract banana juice without excessive energy expenditure, and the juice produced is wholesome with a superior flavour to that produced by the enzymatic method. © 2002 Society of Chemical Industry     

Effect of sucrose‐based polymers on quality of Satsuma mandarin fruit (Citrus unshiu Marc. cv. Miyagawa Wase)

In this study, the effects of an edible coating (sucrose‐based polymers, SBP) on postharvest fruit quality of Satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa Wase) were investigated. All the fruit except the control was sprayed with SBP solution at a concentration of 0.1%, 0.3%, 0.5% and 1.0% (v/v), respectively, and then stored at room temperature (25 °C, 85% relative humidity) for 25 days. Results showed that 0.1%, 0.3% and 0.5% SBP treatment could significantly increase the soluble solids concentrations (SSC), vitamin C (Vc), total sugars, total carotenoids, the ratio of SSC to titratable acidity (TA) (SSC/TA), catalase (CAT), peroxidase (POD) and superoxidase dismutase (SOD) activities, while the decay rate, TA and polyphenol oxidase (PPO) activity were greatly reduced. In contrast, 1.0% SBP treatment resulted in fruit browning, despite maintaining fruit quality. Our present study provided the theoretical data for the practical application of the SBP on the citrus fruit quality of during postharvest storage.     

不同品种龙眼果实加工特性比较研究

以18个龙眼品种的果实为试材,利用常规的加工特性分析方法,进行果实的组成、理化指标、可溶性蛋白、总酚和总抗氧化能力的分析。结果表明:龙眼品种间果实出汁率、可溶性固形物含量、可食率、总酸、糖酸比差异较大,出汁率为36.02%～55.74%,水眼最高(55.74%);华路广眼最低(36.02%),可溶性固形物为11.3%～21.77%,白花木最高(21.77%),青壳宝园最低(11.3%)。18个龙眼品种的多酚氧化酶(PPO)、过氧化物酶(POD)的活性和色泽稳定性差异较大,PPO为0～6.6U,POD为72.7～1816.7U,色泽变化值(ΔE)在30℃时为0.24～3.68,100℃时为7.62～63.53。初步评价:石硖、储粮、白花木、华路广眼和双孖木是适宜于果汁和果酒加工的优良品种。龙眼的总抗氧化能力值在3.73～20.39mmol/L之间,双孖木最高(20.39mmol/L),青壳宝园最低(3.73mmol/L);可溶性蛋白含量分布变幅为45.82～88.8mg/L,石硖最高(88.8mg/L),鸡卵眼最低(45.82mg/L);总酚含量在13.02～749.95mg/L之间,华路广眼最高(749.95...     

Physicochemical and sensory properties of purple Brazilian cherry (Eugenia uniflora,L.) foams

The objective of this work was to characterise the foams of purple Brazilian cherry (Eugenia uniflora L.) pulp made with different additives, aiming at foam‐mat drying. Characterisation was made through analyses of moisture, pH, acidity, soluble solids, density, water activity, colour, total and reducing sugars, protein and ashes. Drying was done at 55 °C for 2 h. Dried Brazilian cherry juice powder was rehydrated for acceptance test. It is concluded that the physicochemical characterisation of fresh Brazilian cherry pulp was satisfactory and was in accordance with the Brazilian standards for agro‐industrial products. Albumin was the best foaming agent that produced a good‐quality powder in a short period. The foam‐mat drying of Brazilian cherry pulp using albumin and Superliga^® (Duas Rodas Industrial ltda, Santa Catarina, Brazil) as foaming agents produced a powder with good physicochemical properties and sensory quality and most preferred juice.     

GREEN UMBU (SPONDIAS TUBEROSA ARR. CAM.) PRESERVE: PHYSICAL, CHEMICAL AND MICROBIOLOGICAL CHANGES DURING STORAGE

A preserve made from “umbu” in the green state of maturity represents an alternative to avoid losses of the fruit in the mature stage. A factorial experimental design was used to evaluate the effects of formulation, packaging and storage time (0, 45 and 90 days) on the physicochemical, chemical, physical and microbiological characteristics of the preserve during storage under ambient conditions (33C/88% relative humidity). The results showed that the products were microbiologically stable, but that degradation of soluble pectin, reducing sugars and total soluble solids occurred, especially in the cellophane packaging, and this resulted in textural and color changes in the products. The results suggested the incorporation of pectin and glucose syrup and the use of a polypropylene packaging as being the most adequate method of producing and conserving preserves made from this pulp.     

SORPTION ISOTHERM BEHAVIOR OF OSMOCONVECTIVELY DEHYDRATED CARROT CUBES

Carrot cubes, osmotically pretreated with aqueous sodium chloride (10%, w/v), sucrose syrup (55°Brix), and mixture of sucrose and sodium chloride (50°Brix + 10%, w/v), were convectively dehydrated at 65C temperature up to final moisture content of 4–5% (wet basis). To study their equilibrium moisture content (EMC) behavior, the dehydrated carrot cubes were stored at temperature ranging from 10 to 50C and relative humidity ranging from 15–95% using static desiccator technique. Five isotherm equations, viz, Chung–Pfost, modified Henderson, modified Halsey, modified Oswin and modified exponential were applied to examine the data. Among the applied models, modified Oswin model was best fit for control (untreated) and salt‐treated samples, modified Hesley model for sucrose‐treated samples and two‐term exponential model for mixture of sucrose–salt treatment over the entire range of relative humidity and temperature. The EMC values of cubes osmotically pretreated with sodium chloride solution were highest among all pretreatments, and were lowest for control (unosmosed) samples.     

蓝莓渗透脱水的研究

在不同的渗透温度 ( 4 5～ 65℃ )条件下 ,高果糖浆和蔗糖的有效水分扩散率 (Dm)分别为( 4 90 60～ 5 2 3 66)× 1 0 - 10 m2 /s和 ( 3 5 5 1 8～ 4 0 1 0 9)× 1 0 - 10 m2 /s,有效固形扩散率 (Ds)分别为( 2 7740～ 3 691 5 )× 1 0 - 10 m2 /s和 ( 1 3 1 63～ 2 691 5 )× 1 0 - 10 m2 /s的规律。在渗透脱水处理过程中Dm 和Ds 随处理温度升高而增加。经高果糖浆 ( 70°Brix)渗透脱水的蓝莓的平均体积比随温度升高而稍微下降。其相对密度随温度的升高也略有增加     

Camu-camu Myrciaria dubia (HBK) McVaugh: Chemical composition of fruit

Abstract : The chemical composition of the Peruvian camu-camu fruit Myrciaria dubia(HBK) McVaugh was analysed at three stages of maturity (immature, midripe and ripe). As fruit matured, levels of ascorbic and dehydroascorbic acids, reducing sugars (fructose and glucose were the major sugars), amino acids (serine, valine and leucine) and soluble solids increased. Citric acid was the major acid (from 19.8 up to 29.8 g kg^?1) and was responsible for the fruit's sour taste. Unlike citric acid, malic acid increased with maturation. Among the macronutrients, potassium was the most abundant mineral (711 mg kg^?1) and could be considered, like vitamin C, nutritionally significant. During maturation, the fruit pulp colour turned from yellow-green to pink, presumably due to the migration of anthocyanin pigments from the peel.     

Chemical composition and antioxidant activity of quince fruit pulp collected from different locations

This study was carried out to examine the physicochemical and functional characteristics of quince fruit pulp. The matured quince fruits were collected from different locations of Poonch, AJ&;K, Pakistan. Significant differences (P ? 0.05) were found among fruits collected from these locations. The quince pulp has the following characteristics: pH (3.43), total soluble solids (14.22°Brix), acidity (1.25%), carbohydrate (13.38 g/100 g), reducing sugar (5.15 g/100 g), non-reducing sugar (4.61 g/100 g), moisture (84.27 g/100 g), ash (0.62 g/100 g), fat (0.24 g/100 g), protein (0.49 g/100 g), fiber (1.65 g/100 g), ascorbic acid (15.46 mg/100 g), and total phenolic (68.13 mg gallic acid equivalent/100 g) and antioxidant activity (50.05%). This exploration is the basic direction, which highlights the nutritional characteristics of quince fruit grown in AJ&;K, Pakistan.     

Kinetic Analysis of Osmotic Dehydration Carried Out with Reused Sucrose Syrup

ABSTRACT Processing times required to achieve a target level of soluble solids were determined in apple pieces during sequential osmotic dehydrations carried out with reused sucrose syrup, in which new loads of fruits were charged in each turn. Effective diffusivities for water and sucrose in apple pieces were experimentally determined as a function of syrup soluble solids. A computer program was written to predict soluble solids change both in apple pieces and in syrup during the sequential osmotic dehydration process. Experimental data on the change of soluble solids for apples and syrup for 10 batches arranged in 2 sets of 5 were obtained. A good agreement between observed and predicted values of soluble solids in both fruit and the syrup was obtained, with root mean square values ranging from 1.3% to 4.6%.     

不同品种荔枝果实加工特性比较研究

以25 个荔枝品种的果实为试材,利用常规的加工特性分析方法,进行果实的组成、理化指标、可溶性蛋白、总酚和总抗氧化能力的分析。结果表明：荔枝品种间果实出汁率、可溶性固形物含量、可食率、总酸、糖酸比差异较大,惠东红岩出汁率最高(70.76%),甜岩最低(32.77%),水晶球可溶性固形物最高(19.57%),香荔最低(12.00%)。荔枝品种的多酚氧化酶、过氧化物酶的活性和色泽稳定性差异较大。初步评价,惠东红岩、糯米糍、园枝、黑叶、中山状元红和白糖罂是适宜于果汁和果酒加工的优良品种。荔枝的可溶性蛋白、总酚和总抗氧化能力差异也较大,分别在0.03～1.26mg/L、11.75～487.35mg/L 和1.90～30.06mmol/L 之间。     

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.     

Yield and quality of juice from passion fruit (Passiflora edulis), maypops (P incarnata) and tetraploid passion fruit hybrids (P edulis × P incarnata)

Yield and properties of juice from purple and yellow passion fruit (Passiflora edulis), maypops (P incarnata) and tetraploid hybrids of P edulis and P incarnata were compared. Weight, proportion filled, number of seeds and yield of juice per fruit were lower in tetraploid hybrids than in P edulis. Acidity and soluble solids were highest in tetraploid hybrids and lowest in maypops. Fructose, glucose, sucrose, citric and malic acids were present in all samples. Fructose and glucose were the major sugars in passion fruit; sucrose was highest in tetraploid hybrids and maypops. Citric, the predominant acid in all samples, was highest in the yellow passion fruit followed by tetraploid hybrids and purple passion fruit. Malic acid was highest in purple-flowered maypop and lowest in white-flowered maypop.     

Laboratory preparation and evaluation of Pollock variety avocado (Persea americana Mill) guacamole

Guacamole was produced from ripe avocado (Persea americana) by blending the pulp with local herbs, spices and salt. The guacamole was stored at 5 °C for 2 weeks, during which physical, chemical and microbial analyses were conducted. Organoleptic evaluations by a semi‐trained panel were also performed, until the guacamole was deemed unfit for human consumption. The results indicated that fresh avocado pulp contains 835, 13, 16, 92, 44, 16 and 0.078 g kg^?1, moisture, ash, protein, fat, carbohydrate, fiber, and vitamin C respectively, and has a pH of 6.7; compared with 838, 13, 16, 92, 44, 16, and 0.042 g kg^?1, respectively, of the same nutrients in freshly prepared guacamole, which has a pH of 6.0. During storage, the moisture content, consistency, total soluble solids and total titratable acidity (as citric acid) of the guacamole increased, but the vitamin C content decreased. The color of the avocado pulp, which darkened during conversion into guacamole, darkened further as storage increased as evidenced by a decrease in the L, a and b values. Sensory evaluation revealed that the mean storage period (5 °C) for the guacamole was 6 days. Although the fresh avocado pulp, the freshly prepared guacamole, and the stored guacamole contained bacteria, yeasts and molds, the pathogens Staphylococcus aureus and Salmonella were absent. Copyright © 2007 Society of Chemical Industry     

Quality parameters of Brassica spp. grown in northwest Spain

The edible portions of different Brassica spp. grown in several areas of Northwest Spain (Galicia) were studied during 2007 and 2008. The aim of the study was to determine and compare the values of some physicochemical parameters (moisture, soluble solids, titratable acidity, pH, protein, ash, vitamin C, total phenolics, chlorogenic acid, caffeic acid, p‐coumaric acid, quercitin and chlorophyll) in different edible portions of turnip greens and turnip tops (Brassica rapa var. rapa), Galega kales (B. oleracea L. var. acephala), white cabbages (B. oleracea L. convar. capitata var. alba) and Savoy cabbage (B. oleracea L. convar. capitata var. sabauda). Different values were obtained for the parameters depending on the variety of plant. In general, the nutrient contents of the turnips and the Galega kales were higher than those of the cabbages. Variations within different edible portions were also observed. Moreover, the mean values of the parameters measured in leaves were higher than those measured in stems, except for moisture content. High concentrations of soluble solids, protein, vitamin C and phenolics were found in the different varieties of Brassica studied.     

Development of cantaloupe (Cucumis melo) juice powders using spray drying technology

Cantaloupes are a good source of carotenoids and vitamin C. Cantaloupe fruit juice powder containing vitamin C and β-carotene can be produced by spray drying. The objective of this study was to develop cantaloupe fruit juice (CJ) powder and to evaluate its nutritional and physical properties. Fresh cantaloupe fruits purchased from a local store were diced and juiced. CJ with 10% maltodextrin (MD) added was spray dried at inlet temperatures of 170, 180 and/or 190 °C. Three spray dried cantaloupe powders, including CJ dried with MD at 170 °C (CJP1), CJ dried with MD at 180 °C (CJP2), CJ dried with MD at 190 °C (CJP3) were analyzed for moisture, water activity, vitamin C, β-carotene, dissolution, and microstructure. The actual production rate of the cantaloupe juice powders was lower than the estimated production rate. CJP1 had (p < 0.05) higher moisture content and water activity than CJP2, and CJP3. Vitamin C content (mg/100 g, dry solids) was significantly (p < 0.05) higher in CJP1 (136.36 ± 5.84) than CJP2 (91.85 ± 5.23) and CJP3 (78.30 ± 1.96). The powder produced at inlet temperatures 170 °C had higher β-carotene content (μg/g) than that produced at 180 and 190 °C.     

Spray Drying of Roselle (Hibiscus sabdariffa L.) Extract

Hibiscus sabdariffa (Roselle) powder was produced by pilot scale spray drying using single strength and vacuum concentrated water extract of its calyces. Powders were analyzed for moisture, protein, vitamin C, total soluble solids (TSS), pH, particle size, bulk density, solubility, dispersibility, hygroscopicity, and microbiological status. The lowest inlet air temperature (198.5°C) resulted in the product with best protein content (12.43%), retention of vitamin C (82.76 mg/ 100g), and solubility (dissolving in 97 sec); as well as the highest moisture content (3.78%) in the product. The powder showed a noticeable tendency to stick to internal surfaces of the drying chamber particularly with concentrated solutions at higher temperatures.     

Evaluation of enzymatic treatment of peach juice using response surface methodology

BACKGROUND: This work aimed to assess peach juice clarification using enzymatic treatment. The enzymatic hydrolysis was performed to reduce the juice viscosity and pulp content, and consequently to increase juice extraction. The hydrolysis conditions were optimized by the response surface methodology, where the influence of temperature, amount and type of enzyme and time of reaction were investigated. RESULTS: Two commercial pectinase preparations (AFP L3 and ULTRA SP WOP from Novozymes) as well as a cellulase (R10 from Onozuka) were tested. The hydrolysis using Pectinex AFP L3 (Novozymes) at 25 °C for 60 min presented the best results of pulp (48%) and viscosity (68%) reduction. CONCLUSION: Physical and chemical analyses showed that the enzymatic treatment is effective for reduction of peach pulp viscosity, pulp content and turbidity and does not influence other juice parameters such as pH, total acidity, vitamin C and soluble solids. Copyright © 2007 Society of Chemical Industry     

营养型柿子酒生产技术

以澄清柿汁、食用酒精、蔗糖、蜂蜜等为原料,将柿汁醇化后,加入30 mL糖浆、80 mL纯净水和1.0 g柠檬酸调配而制成糖分含量高、酒精度低、风味独特的营养型柿子酒.