Characteristics and Potential Use of Guava (Psidium Guajava L) for Processing of Concentrate

Studies were conducted to determine the characteristics of guava (Psidium guajava L) cv. Vietnamese of its potential use for processing it into guava concentrate. A maturity study showed that the guava took 16 weeks to reach maturity. The best indices of maturity were size, moisture, sugars and tannin contents. The moisture content at the mature stage was 94%. The fructose ,glucose and sucrose contents were 2.02%, 1.08% and 1.54%,respectively. The tannin content in the matured guava was low (37.0 mg/10gm sample) but the vitamin C content was high (76mg/100g sample). The structure of stone cells in guava fruits were examined microscopically. The stone cells became more prominent with increase in fruit maturity,hence the prepared puree were pulverised in order to improve its texture. Studies on the quality of puree produced from fruits at different stages of maturation showed that a puree of desireable quality was obtained from fruit sat the yellow green stage (stage 4). Artificial ripening was necessary to soften the fruits to make them ideal for processing into concentrate or puree.Fruit sat the yellow green stage had an increase in soluble pectin content to 67%. This increased the viscosity of puree . The vitamin C content also increased from 79.7mg-131.1mg/l00g sample. The puree showedless tendency to turn brown due to the low tannin contents(21mg/10g samples)

Effect of Processing Techniques on the Quality and Acceptability of Young Carambola (Averrhoa carambola) Fruit Pickle

The potential use of young carambola fruits for pickle production was studied using the conventional salt-stock and the blanching methods. Fruits Pickled were in the form of whole fruits and thick and thin slices. The suitability of each technique was graded based on the quality and acceptance of the final product. Samples for analysis were taken at different stages of processing and were analysed for ascorbic acid content, titratable acidity, and texture; and the final product was subjected to sensory analysis for evaluation on crunchiness, taste, flavour and size preference. There was no significant difference in the physical and chemical quality of products obtained from both methods but sensory evaluation showed that the blanched, thickly sliced pickle was preferred for its crunchiness. However, storage study showed that the blanched pickle became soft after 1 month. The water activity of the pickle was 0.94

Effects of Brix, processing techniques and storage temperature on the quality of carambola fruit cordial

Two methods of processing carambola fruit cordial were compared using a cold method (CM) and a hot method (HM). Characteristics of the freshly prepared product were compared. Samples were later prepared at 35 °, 45 ° and 55 ° Brix concentrations and stored at 25 °C and 5 °C. The responses measured during storage were changes in pH, titratable acidity, ascorbic acid content, Brix, viscosity, colour, pulp sedimentation and sensory attributes of colour and taste. The pH remained stable during storage but did not show any correlation with titratable acidity, which fluctuated. The ascorbic acid content decreased. Temperature seemed to have an effect on Brix and viscosity values, colour and pulp sedimentation. The 35 ° and 45 ° Brix CM cordials stored at 5 °C were more acceptable in terms of colour and taste. CM did not seem to be a feasible technique for producing cordial from fresh fruit

Changes in tannin and pectic substances at different positions within a bunch of Cavendish Banana (Musa cavendishii L. var. Montel) during development and maturation

Studies were carried out on changes in the tannin content, alcohol insoluble solids (AIS) and pectin fractions (water, ammonium oxalate and sodium hydroxide solubles) of Cavendish banana variety Montel at different positions within a bunch during maturation and ripening. There was a significant decrease (P<0.01) in the tannin content between the different portions of hands within a bunch and between different fingers within a hand during maturity. AIS increased at the early stages, but it decreased significantly (P< O. 05) in the ripe fruits (week 12). There was a significant difference (P<0.05) in the pectic substances at different positions within a bunch during maturity. The pectins increased at the early stages, reaching a maximum at week 12 and then slowly decreased. At the end of maturation, the pectic substances started to increase slowly until ripening. There were also significant differences (P<0.05) in the tannin content, AIS and pectic substances during maturity between different portions of hands and fingers. However, significant differences (P<0.05) were observed between portions of hands within a bunch and between fingers within a hand during maturity stage; the top hands and upper fingers were higher in tannin, AIS and pectic substances contents than the middle and bottom hands within a bunch and lower fingers within a hand respectively

Effect of waxing with paraffin and modified atmosphere packaging on the storage of Cavendish Banana (Musa cavendishii L var. Montel)

Postharvest treatment with liquid paraffin, clingwrap, low density polyethylene (WPE) with and without potassium permanganate (KMnO) was studied to extend the shelf life of 'Montel' banana (Musa cavendishii L), under refrigeration (15±1 °C) and at ambient temperature (27±1 °C). The fruits packed in WPE with KMn04 ripened within 60 days after harvesting at week 12 from flower emergence. This was followed l7y treatments with clingwrap (42 days), liquid paraffin (36 days), control at 15±I°C (24 days) and control at ambient temperature (18 days). The percentage weight loss, peel and pulp colours of fruits increased significantly (P<O.OI) for all treatments during the storage period. On the other hand, the texture values and tannin content of the fruit decreased significantly (P<O.OI). The rise in total soluble solids (TSS) and sugar was slow initially but gradually increased at the end of the storage period. However, pH, titratable acidity (TA), ascorbic acid (AA) and starch contents o fruits from all treatments were found to be inconsistent during storage. There is a highly significant (P<O.OI) difference in the production of ethylene (CIl) and carbon dioxide (CO) found from fruits of all treatments during storage. Fruits packed in low density polyethylene (WPE) with KMn04 was found to be the best treatment to extend the storage life of 'Montel' banana

Effect of different dryers and drying conditions on acceptability and physico-chemical characteristics of durian leather

Optimization study on drying condition of durian leather was carried out using Response Surface Methodology (RSM). The optimization was conducted for two different dryers, oven dryer and forced-air cabinet dryer, with temperature and time of drying as independent variables. It was shown that both variables significantly affected most of the sensory properties. For both dryers, the optimum points for 5 sensory attributes evaluated including taste, aroma, texture, appearance and overall acceptability, were at temperatures ranged from 47-55C for 10-14 h. Based on the overall acceptability, the optimum condition for ovendried leather was achieved at temperature 50C for 12.6 h, while for cabinet-dried leather at 52.5C for 10 h. Results showed that panelist preferred product dried with low temperature-long time compared with high temperature-short time. Except for Hunter color b value of cabinet-dried product, results also indicated that drying condition was significantly influencing the physico-chemical properties such as moisture, Aw, nonenzymatic browning, texture, vitamin C and color of durian leather

Physico-chemical changes in sugarcane (Saccharum officinarum var yellow cane) and the extracted juice at different portions of the stem during development and maturation

A study was conducted to determine the physicochemical differences between portions (top, middle, and bottom) of sugarcane at different maturation stages (between 3 and 10 months from planting). The variety used was Saccharum officinarum var. Yellow cane. The parameters analysed were weight, diameter, yield, total soluble solids (TSS), pH, titratable acidity, sugar content (sucrose, glucose, fructose). The weight, diameter, total soluble solids (TSS) and sucrose content increased significantly (P<0.01) in all portions (top, middle and bottom) up to the end of maturity. On the other hand, titratable acidity (TA), pH, juice yield, glucose and fructose contents decreased significantly (P<0.01) during maturation. However, significant differences were also detected in weight, diameter, TSS, sugar content, pH, TA and juice yield between the different portions during maturation. Sucrose content, juice yield and TSS were found to be the most suitable indicators of maturity, while TA, glucose and fructose contents were found to be poor maturity indicators. A suitable harvesting stage was found to be between 7 and 8 months after planting. Copyright © 2001 Elsevier Science Ltd

Effect of glucose syrup solid, sucrose, hydrogenated palm oil and soy-lecithin on sensory acceptability of durian leather

A two-stage optimization of ingredients in durian leather formulations was conducted using Response Surface Methodology (RSM). In stage 1, the independent variables were glucose syrup solids (GSS) and sucrose, and in stage 2, the variables were hydrogenated palm oil (HPO) and soy-lecithin (SL). Based on the responses to sensory acceptability attributes including taste, aroma, texture, appearance and overall acceptability, the most acceptable formulation was a combination of 10% GSS, 5% sucrose, 2.67% HPO and 0.452% SL. Chemical analysis also showed that during processing nutrient composition was relatively unchanged