Total Soluble Solids Titratable Acidity Research Articles

Freeze-dried pulp and peel from pitahaya (Selenicereus undatus): physicochemical properties and potential source of fructooligosaccharides

The pitahaya Selenicereus undatus is a fruit widely consumed in the Yucatan Peninsula in Mexico, and its cultivation is promising due to its adaptability to adverse climatic conditions, its nutritional quality, and its bioactive compounds. The objective of this work was to determine the physical parameters of the fresh fruit (weights and diameters) and chemical parameters of the pulp (stored at -18 ºC) of pitahaya grown in two locations in the state of Yucatán, as well as to estimate the yield of fructooligosaccharides (FOS) present in freeze-dried pulp and peel flour, using the solid/liquid extraction method. Six physicochemical and six proximal descriptors (in freeze-dried pulp and peel), which were statistically compared using the t-student test, were quantified. The fruits had an average weight of 534.81 and 520.36 g for the pitahaya grown in Kinchil and Yobain, respectively. The peel weight of the fruit from Kinchil was significantly (p < 0.05) higher. The pulp represented between 67 – 72 % of the weight of the fruits. The physicochemical analysis of the fruit pulp indicated that the average total soluble solids/titratable acidity (TSS/TA) ratio was 20.5, and the pH was 3.29. The proximal analysis expressed on a dry basis (% d.b.) showed average values for the pulp of 4.80 % ash, 0.47 % crude fat, 10.42 % crude fiber, and 6.92 % protein; while for the peel 14.20 % ash, 1.39 % crude fat, 22.22 % crude fiber, and 5.31 % protein. The values of crude fiber and total carbohydrates in the peel, as well as the crude fat content in the pulp, were different (p < 0.05) between the locations. The estimated extraction yield of FOS with water was 86.49 g/kg for the freeze-dried pulp and 17.64 g/kg for the freeze-dried peel flour. This fruit exhibited good nutritional properties, and the freeze-dried flour from its peel could be used as supplement rich in dietary fiber and, together with the freeze-dried pulp, could be added to products such as juices, yogurt, and jams, among others, with a potential prebiotic effect due to its fructooligosaccharides content.

Physicochemical characteristics of pomegranate fruits as affected by foliar application of potassium and zinc

Foliar application of mineral nutrients can considerably improve fruit yield and quality. In this study, the effects of K and Zn application by spraying on leaf mineral contents, and some physical and biochemical characteristics of pomegranate fruits cv. ‘Malas Saveh’ were investigated. The mineral treatments were three concentrations of K2SO4 (0, 1, and 2%) and three concentrations of ZnSO4 (0, 0.5, and 1%). The solutions were applied in 2020–2021 and in four times: the first application was during the time of flowering and rest three applications were applied at two-week intervals. The results showed that leaves of trees fed with different concentrations of K2SO4 and ZnSO4 accumulated higher concentrations of N, P K, Zn, Fe, and Mn than those untreated. Pomegranate trees treated with the mineral treatments had higher chlorophyll a and total chlorophyll. Applying most mineral treatments, especially 2% K2SO4+0.5% ZnSO4, significantly increased the fruit yield, fruit diameter, fruit length, aril percentage, aril/skin, the weight of 100 arils, and juice content of 100 g arils, but reduced the cracking percentage, skin thickness, skin percentage and firmness of fruits. Moreover, fruits of pomegranate trees treated with the most mineral treatments and especially 2% K2SO4+0.5% ZnSO4, showed a greater level of TSS (total soluble solids), TSS/TA (total soluble solids/titratable acidity), anthocyanin, total phenol, flavonoid, antioxidant activity, and vitamin C, and a lower level of TA. The study results evidenced that K and Zn application by spraying has a high potential for improving fruit yield and quality of pomegranate.

Postharvest application of Aloe vera gel and thymol enhances shelf-life of duke cherries via altering physiochemical parameters

BackgroundDuke cherry is a non-climacteric fruit but deteriorates quickly during storage due to thin pericarp and succulent fruit tissue. The application of edible coatings, essential oils, or their combination is an appropriate technique to maintain the quality characteristics and reduce the deterioration of fruits during storage. This research assessed the effect of Aloe vera gel (AVG), thymol, and their combined use on the physicochemical and qualitative properties of duke cherries kept at 5 °C and 80% relative humidity for 28 d.ResultsCompared to the uncoated fruits, duke cherries coated with a combination of AVG and thymol, showed more values of firmness (12.76–100.32%), total phenol (9.99–45.09%), antioxidant activity (7.90–84.56%), and sensory scores(50.15–100.00%), as well as the activity of guaiacol peroxidase (GPX) (12.03–185.11%) and catalase (CAT) (10.20–243.66%) enzymes during cold storage. Moreover, duke cherries coated with a combination of AVG and thymol had remarkably lower values of weight loss (32.57–42.67%), respiration rate (34.96–49.78%), stem browning (24.50–50.53%), spoilage percentage (84.55–100%), anthocyanin (14.21–23.16%), and total soluble solids/titratable acidity (TSS/TA) (35.64–50.15%), as well as hydrogen peroxide (H2O2) (16.66–32.35%) and malondialdehyde (MDA) (15.23–31.05%).ConclusionThe application of AVG and thymol, particularly their combination, can have a high practical potential to extend shelf-life and preserve the quality of duke cherries during cold storage. This treatment has various advantages including natural, edible, cost-effective, and efficient.Graphical

Determination of physicochemical quality of bruised apple using dielectric properties

In this study, apples were damaged by dropping from different heights(40、60、80、100 and 120 cm) to the marble ground and stored at 1 °C and then the quality and dielectric parameters of the apples were measured after different storage durations (1、5、9、13、17、21 and 25 d). The results showed that the firmness, density, titratable acidity (TA), vitamin C and moisture content decreased, the browning degree and total soluble solid/titratable acidity(TSS/TA) increased, the total soluble solid (TSS) exhibited a increasing–decreasing trend with the storage time increased. The higher the drop height of the apples, the lower the firmness, density, TSS, TA, vitamin C and moisture content and the greater the browning degree and TSS/TA. A principal component analysis showed that two principle components could represent the dielectric parameters of the damaged fruit, and the accumulated variance contribution rate was more than 80%. At the characteristic frequency, which was selected using a gray correlation analysis, the principle components predicted the quality parameters and established the prediction models for quality parameters. The determination coefficients of prediction equation about density, TSS, TA, vitamin C and moisture content were all greater than 0.6, it was indicated that the prediction results of these quality parameters were better. The results are expected to provide a reference for the rapid evaluation of quality changes for damaged fruit by using electrical properties.

NUEVOS INDICADORES DE VIDA COMERCIAL Y CALIDAD DE NARANJA cv Valencia (Citrus sinensis Osbeck)

Mexico is the fifth largest producer of fresh oranges in the world, and Tepalcingo in Morelos has recently become an important area of cultivation for cv Valencia. The objectives of this work were to assess fruit quality in the oranges from this region, and to determine their commercial life during storage. Significant differences occurred in the juice volume of fruits during all three seasons evaluated; however, no differences were detected in their weight, size, shape, rind thickness, or flavedo color (L*, C*, h). TSS/TA (total soluble solids/titratable acidity) ratios were high (10.3-12.9) in fruits collected during spring and summer. Overall, the oranges met the specifications of both national and international quality standards. Changes during storage indicated that compression force, % weight loss, and sensorial flavor were negatively impacted by storage at 24⁰C while TSS and TA of juice remained unaffected at 11 and 24 ⁰C. The commercial life of oranges was 21 d at 24 ⁰C and > 28 d at 11 ⁰C as determined from changes in the concentrations of certain aroma compounds and from differences in the firmness of their rinds. Such changes correlate well with both weight loss and the sensorial perception of quality attributes.

Non-destructive Assessment of Guava (Psidium guajava L.) Maturity and Firmness Based on Mechanical Vibration Response

Storage potential and eating quality of guava (Psidium guajava L.) fruit depend on its maturity. Segregation of guava according to maturity and firmness measured using non-destructive technologies would help the industry to designate ripe fruit to immediate market and less ripe fruit for distant market (e.g., exportation). This research was conducted to evaluate the potential of experimental resonant frequency (fe) and elasticity index (EI) to estimate fruit firmness, which has been reported to be inversely correlated to its maturity. A maturity index (Im) was calculated as the ratio of total soluble solids/titratable acidity (TSS/TA). It was proved that TSS, TA, and Im were significantly correlated (P < 0.05) to skin firmness (Fs), flesh firmness (Ff), stiffness (S), and analytical resonant frequency (ωn), being S the attribute best fitted to Im (R2 = 0.77). Since it was observed that fe and EI were sensitive to changes in fruit firmness, both of them were explored as alternatives to predict Fs, Ff, S, and ωn of guava fruit. In some cases, EI improved the models to predict guava firmness traits (e.g., Fs vs fe had a coefficient of determination of R2 = 0.58, whereas for Fs vs EI, it was R2 = 0.62). The best model occurred when plotting ωn vs fe (R2 = 0.86), followed by S vs EI (R2 = 0.84), making these promising features for the development of a new practical application using frequency response measurement as a non-destructive method to assess guava maturity.

Juice of New citrus hybrids (Citrus clementina Hort. ex Tan.×C. sinensis L. Osbeck) as a source of natural antioxidants

Fruit juices of pigmented and non-pigmented new citrus hybrids obtained by crossing clementine cv. Oroval with different cultivars of blood oranges were analysed to determine parameters related to fruit quality (total soluble solids titratable acidity, pH), and the content of ascorbic acid, total phenolics, flavanones, anthocyanins and phenolic acids. Antioxidant properties were evaluated by oxygen radical absorbance capacity (ORAC), and inhibition of induced linoleic acid peroxidation (InLAP) assays. The results of this study show that some hybrids with high antioxidant activity owing to considerable polyphenol content may be considered rich sources of phytochemicals. The OTA 9 hybrid was shown to be richest in polyphenols, suggesting that consumption of OTA 9 fruit or juice could be useful in health promotion and a disease-preventing diet. Moreover, the juice of this hybrid could be used as raw material to produce antioxidant ingredients for dietary, pharmaceutical, or cosmetic purposes.

Influence of delayed cooling on storability and postharvest quality of European plums

AbstractBACKGROUND: Delayed cooling has been tested to delay the development of internal breakdown (IB) in other stone fruits, but the influence of delayed cooling on IB has not been studied to date in European plums. A controlled delayed treatment of 48 h at 20 °C was applied in order to study the storability and postharvest quality of European plum (Prunus domestica L.) cv. ‘Green Gage’.RESULTS: Market life of ‘Green Gage’ plums after shelf life was 10 days shorter in delayed fruits than in control fruits at earlier harvest dates. Sensory attributes affected by delayed cooling treatment at harvest were astringency and aroma. Prompt cooling was essential to lower the rate of physiological deterioration of plums, helping to maintain fruit quality and prolong market life.CONCLUSION: Delayed cooling increased IB symptoms in ‘Green Gage’ plums, so, when storability is needed, rapid cooling of fruits is necessary in order to extend their market life. Delayed cooling modified the total soluble solids/titratable acidity (TSS/TA) ratio and the sensory properties aroma and astringency at harvest, so it is desirable to deliver fruits directly to market in order to improve TSS/TA, the instrumental property best correlated with sensory characteristics. Copyright © 2009 Society of Chemical Industry

“Heirloom” varieties as sources of variation for the improvement of fruit quality in greenhouse-grown tomatoes

SummaryGreenhouse-grown tomatoes (Lycopersicon esculentum) often have poor internal organoleptic and nutritional qualities. “Heirloom” (traditional) varieties of tomato possess unique or superior fruit quality characteristics and may be useful for the development of new greenhouse tomato cultivars with improved internal quality. A collection of 55 North American “heirloom” varieties was evaluated for fruit colour, shape, weight, firmness (external quality traits) and total soluble solids (TSS) content, titratable acidity (TA), TSS:TA ratio, flavour intensity (FI; TSS TA) and ascorbic acid (AA) concentration (internal quality traits). The F1 hybrid ‘Daniela’ and pure line ‘NE-1’ were used as controls. A wide diversity was found among “heirlooms” for all traits studied, and several sources of variation (e.g., varieties ‘Moira’, ‘Paragon’, ‘White Queen’, ‘Black Prince’ and ‘Green Zebra’) useful for the improvement of fruit quality were identified. Brightness (L*), hue angle and chroma parameters facilitated the classification of varieties into colour groups (white, yellow, orange, red or black) and the identification of the varieties with better colour characteristics within each colour group. Although all “heirloom” varieties had lower firmness than the delayed ripening cv. ‘Daniela’, some of them (e.g., ‘Moira’ and ‘Paragon’) were very firm. Values obtained for TSS, TA, FI and AA demonstrated that many “heirloom” varieties had better organoleptic and nutritional qualities than modern varieties. As considerable variation was found for most traits, some of the materials studied represent sources of variation of great interest for tomato breeding.

Effects of Organic Matter and Nitrogen Fertilizer Applications on Fruit Quality of Satsuma Mandarin in a High Density Planting.

A differential nitrogen (N) fertilization trial for a high density planting of satsuma mandarin was conducted for 11 years starting in 1982 on 13-year-old trees. Satsuma mandarin (Citrus unshiu Marc. cv. Sugiyama) trees, which had been grown in a 0.4 ha field with little or no fertilizer, were administered a combination of 2 levels of organic matter application and 3 levels of N triplicated in a factorial arrangement. Levels of organic matter were +OM (rice straw application of 20 t·ha-1·year-1) and -OM (sod culture system). Levels of N fertilizers were N-1 : 100, N-2 : 200, and N-3 : 300 kg·ha-1·year-1. The total soluble solids-titratable acidity (TSS-TA) ratio of the juice, the 'a' index of peel color, percentage of mesocarp, and specific gravity of fruit in the -OM treatment were slightly higher than those in the +OM treatment. In contrast, TA content in the juice and mean fruit weight were slightly increased by organic matter application. TSS-TA ratio, the color indices of 'L', 'a' and 'b', % of mesocarp, and specific gravity of fruit decreased with increased N application, whereas TA content in the juice increased. The N and K contents in the leaves and leaf color index in the +OM treatment were slightly higher than those in the -OM treatment. Leaf N content and the leaf color index increased, but leaf P and K contents decreased with increased N application. TSS, TSS-TA ratio, the 'L', 'a' and 'b' color indices, % of mesocarp, and specific gravity of fruit were negatively correlated to leaf N content, wherease TA content correlated positively with leaf N.