Chemical Quality Attributes Research Articles

Changes in Chemical and Physical Quality Attributes of Olives as Influenced by Chemical Control of the Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera, Tephritidae) in Jordan

The olive fruit fly, Bactrocera oleae (Rossi) (Diptera, Tephritidae) is the most devastating insect pest possessing severe economic threats for the olive growers in Jordan. Therefore, the current study aimed at determining the effect of insecticidal applications against B. oleae on olive quantity, as well as physical (refractive index, fruit weight, diameter and volume, and weight of seed and flesh, as well as oil percentage) and chemical (olive oil acidity and peroxide value parameters). The experiment was conducted using Nabali olive cultivar in Karak District-Jordan in the year 2016. Three insecticides; Karate, Fytoclean, and Dursban used in the spraying operations, and trees were sprayed twice. Insecticidal spraying significantly (P<0.05) reduced olive oil acidity, peroxide value, and refractive index, and increased olive fruit’s weight, diameter and volume, and seed, and flesh weight compared to the untreated trees. In conclusion, the application of insecticides against B. oleae improved the olive quantity and tested quality parameters.

Postharvest quality assessment of apple during storage at ambient temperature

In this study, the physical and chemical quality attributes of apples were measured experimentally during the storage after harvesting, using well-defined procedures and techniques. Overall quality index (OQi) models were formulated in terms of measured quality attributes. Firmness (F) and total soluble solids (TSS) varied from 11.88 ± 0.25 to 7.68 ± 0.24 N and 14.1 ± 0.1 to 12.7 ± 0.1 % Brix, respectively, whereas acidity and density varied from 0.163 ± 0.003 to 0.081 ± 0.001 % and 0.995 ± 0.003 to 0.951 ± 0.004 gm/cm3, respectively. The gloss values at 45° and 60° angles of incidence were found to be in the range of 7.9 ± 0.2 to 4.1 ± 0.3 and 6.8 ± 0.1 to 2.5 ± 0.3, respectively whereas, the Hunter color values L, a, b were found to be in the range of 51.75 ± 1.33 to 57.01 ± 0.98, 24.20 ± 0.86 to 30.12 ± 1.13, and 19.53 ± 1.61 to 22.96 ± 1.12, respectively. Formulated models were validated with the sensory scores. OQi predicted by the Model ML2 was found to be in consonance with the variation in the sensory overall quality scores. The OQi, as per the model ML2, was estimated as the ratio of the product of the constant C (265.5), acidity (A), and firmness (F) to the mod of the product of Hunter color values a and b. Finally, the predicted values of OQi were correlated with the measured quality parameters to check the possibility of predicting OQi non-destructively by using any one of those measured attributes during the storage.

Productive Characteristics and Fruit Quality Traits of Cherry Tomato Hybrids as Modulated by Grafting on Different Solanum spp. Rootstocks under Ralstonia solanacearum Infested Greenhouse Soil

Grafting is increasingly becoming an indispensable tool that minimizes the risks associated with intensive vegetable production systems, including soil-borne diseases. This study assesses the performance of two cherry tomato hybrids (‘Cheramy’ and ‘Sheeja’) grafted onto three tomato and five eggplant local rootstock genotypes (cultivated/wild) under Ralstonia solanacearum (bacterial wilt)-infested greenhouse soil. The impact of grafting on growth, yield and fruit physical quality was mainly influenced by the response of rootstocks to disease resistance. The non-grafted plants of both the cultivars were severely affected by bacterial wilt, thus presenting high susceptibility to disease. Eggplant rootstocks imparted moderate to high resistance against bacterial wilt in both the scions, while tomato (cultivated or wild) rootstocks did not improve disease resistance, except ‘Anagha’, which provided resistance to scion cv. ‘Cheramy’. In general, scion cv. ‘Cheramy’, grafted or non-grafted, showed superior growth, yield and fruit quality compared to ‘Sheeja’. The most productive graft combinations for both the cultivars involved resistant rootstocks, i.e., ‘Sheeja’ onto eggplant rootstock ‘Surya’, and ‘Cheramy’ onto tomato rootstock ‘Anagha’. Fruit quality attributes such as ascorbic acid and lycopene contents were considerably higher, and the total soluble solids (TSS) content was considerably lower in scion cv. ‘Cheramy’, whether grafted or non-grafted, than those involving scion cv. ‘Sheeja’. The grafting effect on fruit chemical quality attributes was not promising, except grafting ‘Sheeja’ onto ‘Sopim’ for TSS, ‘Sheeja’ onto ‘Sotor’ for lycopene and ‘Cheramy’ onto ‘Ponny’ for total phenols, though no clear connection with disease incidence was in these grafts. Conclusively, eggplant rootstock imparted wilt resistance, while both eggplant and tomato rootstock grafting was beneficial to both scion cultivars in boosting the overall production and economic gains, especially for ‘Cheramy’ grafted onto ‘Anagha’ rootstock under bacterial wilt infested soil of greenhouse.

Physical and Chemical Fruit Quality Attributes of Two Pomegranate Cultivars Grown at Varying Altitudes of Al-Hajar Mountains in Oman

The present study investigated the differences in fruit physical and chemical quality characteristics of two popular local pomegranate cultivars, namely Helow and Malasi, as influenced by the altitudinal microclimates. Three sites of varying altitudes were selected for this study at Al-Hajar Mountains in northern Oman that included, high (2019 m, Saiq), mid (1876 m, Sograh) and low altitudes (1540 m, Wakan). The results showed that at lower altitudes of Wakan, the Malasi cultivar had better color attributes than Helow cultivar. Malasi also had more lightness (L), yellowness (b) and color intensity (chroma) but less greenness (a), while in mid-altitude, Helow had better color compared with Malasi cultivar. Furthermore, Helow colors was developed as evidenced in terms of brightness, skin and arils redness at higher altitude compared to the two lower altitude sites. Physical fruit qualities were also investigated and the results indicated that in most measured parameters, the Malasi fruit quality was better in both locations (Sograh and Wakan) than Helow cultivar, while Helow cultivar had superior fruit quality at higher elevation in Saiq. Additionally, Malasi had higher juice volume (JV), total soluble solid (TSS) and titratable acidity (TA) than Helow in Wakan. Helow fruits in Saiq showed better performance and higher results for juice volume (JV), total soluble solid (TSS) and maturity index (MI) as followed by those in Sograh and Wakan. Our study showed that the fruit physical and chemical quality attributes of local pomegranate cultivars are strongly influenced by growing location and altitude.

A Comparative Study of Sheep Breeds: Fattening Performance, Carcass Characteristics, Meat Chemical Composition and Quality Attributes.

Fattening performance, Carcass characteristics, chemical composition, and meat quality were evaluated in three sheep breeds: Awassi, Harri, and Najdi. Forty-five lambs of similar weight and age were raised for 90 days under similar conditions. The Harri and Najdi breeds had higher dressing-out percentages than Awassi sheep. The Awassi and Harri breeds had thicker backfat than the Najdi breed. No significant difference was found in moisture, protein, and intramuscular fat among the breeds. However, the Harri breed had a higher ash content than the Awassi and Najdi breeds. The Najdi breed had higher ultimate pH and lower cooking loss than the Awassi and Harri breeds. Awassi and Harri sheep had a higher myofibril fragmentation index, longer sarcomere length, and lower hardness and chewiness than Najdi sheep. Subjectively, no significant differences were detected between the breeds, except for flavor intensity while the Awassi sheep were rated in between and not significantly different. In conclusion, breed affected carcass characteristics, meat composition, and the quality of sheep. The dressing yield was higher in Harri and Najdi than Awassi sheep. Awassi sheep showed superior meat quality characteristics followed by Harri sheep. However, Najdi sheep had the best cooking loss percentage and flavor intensity score.

Evaluation of Food Quality of Released Barley Varieties Grown in Oromia, Ethiopia

This study was conducted to characterize and evaluate food quality of released food barley varieties through physical, chemical and sensory evaluation. Fifteen released food barley varieties were collected from different research centers. Physicochemical qualities of these varieties were analyzed with three replications. Sensory evaluation was also performed by using hedonic scale method. Hectoliter weight, thousand kernel weight, moisture, protein, sodium, potassium, iron, zinc, calcium and magnesium contents were determined in the range of 55.57 – 66.67 grams, 33.50 – 58.50 grams, 7.46 – 11.43%, 9.44 – 16.80%, 79.23 – 316.54 ppm, 3993 – 6040 ppm, 11.49 – 64.32 ppm, 31.07 – 55.73 ppm, 305.42 – 716.91 ppm and 811.50 – 1731.10 ppm respectively. Overall acceptability of porridge prepared from barley varieties were disliked slightly to liked moderately while liked slightly to liked moderately for Injera. There were significant (P<0.05) variation in physical, chemical and organoleptic properties due to test barley varieties variation. Aruso variety was the highest in mean value of thousand kernel weight and hectoliter weight. Walker variety had the highest protein mean score. The study revealed that Robera, Abdane, Bentu, Harbu, Golden Eye and Walker varieties had the highest value of calcium, magnesium, potassium, sodium, iron and zinc respectively. Walker variety porridge was disliked slightly and Bentu variety was mostly liked moderately but not significantly different among Aquila, Gobe, HB 1966 and Robera varieties. Abdane variety injera was liked slightly and Biftu variety was mostly liked moderately but not significantly different among nine barley varieties. Therefore Aruso, Biftu, Bentu and Robera varieties were preferred for physical, chemical and sensory quality attributes.

Effect of pruning regimes and fertilizer levels on quality and economics of guava (Psidium guajava L.)

The experiment framed was intended to find out the optimum level of pruning and economic dose of fertilizer for higher yield and quality production of guava fruits. The results of the present investigation indicated that, different pruning treatments and fertilizer levels produced significant effect on fruit quality of guava. Physical and chemical quality attributes were recorded better in 45 cm pruning level with application of 125% RDF (1000:500:500 g NPK/tree) treatment. The maximum net monetary returns (Rs. 4,97,933/ha.) with highest (2.95) B: C was also obtained with the application of the said treatment.

Yields, Fruit Quality, and Water Use in a Jalapeno Pepper and Tomatoes under Open Field and High-tunnel Production Systems in the Texas High Plains

The Texas High Plains has a semi-arid, hot, windy climate that features high evapotranspiration (ET) demands for crop production. Irrigation is essential for vegetable production in the region, but it is constrained by depleting groundwater from the Ogallala Aquifer. High-tunnel (HT) production systems may reduce irrigation water demand and protect crops from severe weather events (e.g., hail, high wind, freezing) common to the region. The objective of this study was to compare yields, fruit quality, crop water use, and crop water use efficiency (WUE) of jalapeno pepper (Capsicum annuum L.) and tomatoes (Solanum lycopersicum L.) in HT and open field (OF) production systems. We hypothesized that the protection from dry and high winds by HT would improve yields and quality of fruits and reduce water use of peppers and tomatoes. During the 2018 and 2019 growing seasons, peppers and tomatoes were transplanted on two HT plots and two identical OF plots. Plastic mulch was used in combination with a surface drip irrigation system. Micrometeorological variables (incoming solar irradiance, air temperature, relative humidity, and wind speed) and soil physical variables (soil temperature and volumetric soil water) were measured. Air temperatures were significantly higher during the daytime, and wind speed and light intensity were significantly lower in HT compared with OF. Despite the lower light intensity, yields were greater in HT compared with OF. The fruits grown in HT did not show significant differences in chemical quality attributes, such as ascorbic acid and lycopene contents, compared with those grown in OF. Because of protection from dry, high winds, plants in HT required less total water over the growing seasons compared with OF, resulting in increased WUE. The 2018 and 2019 data showed that HT production is advantageous as compared to conventional OF production in terms of increased WUE and severe weather risk mitigation for high-value vegetable production in the Texas High Plains.

Effects of Olive Leaf Extracts as Natural Preservative on Retailed Poultry Meat Quality.

Poultry meat is commonly marketed at refrigerated temperatures (2–5 °C). The major concern for retailers and consumers is the quality and safety of refrigerated poultry meat. During the chilling period, poultry meat undergoes too many undesirable changes due to microbial growth that leads to spoilage and economic loss. Therefore, this study was conducted to assess the effects of olive leaf extracts (OLE) used at three concentrations (0.25, 0.5, and 1%) on the sensory attributes, as well as the chemical and microbiological quality of raw poultry meat stored at 4 ± 1 °C for 15 days. The results revealed that the OLE addition reduced microbial growth successfully, and maintained the chemical quality and sensory attributes of poultry meat. Moreover, OLE extended the shelf-life of the poultry meat that held under proper refrigeration conditions up to 15 days compared to the control group, that was completely spoiled by the sixth day of storage. This study concludes that OLE could be used both as a natural antioxidant and an antimicrobial preservative for chilled poultry meat held at refrigerated temperature.

Comparison between Hyperspectral Imaging and Chemical Analysis of Polyphenol Oxidase Activity on Fresh-Cut Apple Slices

The assessment of the quality of fresh-cut apple slices is important for processing, storage, market value, and consumption. Determination of polyphenol oxidase activity (PPO) in apples is critical for controlling the quality of the final product (i.e., dried apples and juices). Hyperspectral imaging (HSI) is a nondestructive, noncontact, and rapid food quality assessment technique. It has the potential to detect physical and chemical quality attributes of foods such as PPO of apple. The aim of this study was to investigate the suitability of HSI in the visible and near-infrared (VIS-NIR) range for indirect assessment of PPO activity of fresh-cut apple slices. Apple slices of two cultivars (cv. Golden Delicious and Elstar) were used to build a robust detection algorithm, which is independent of cultivars and applied treatments. Partial least squares (PLS) regression using the 7-fold cross-validation method and method comparison analysis (Bland–Altman plot, Passing–Bablok regression, and Deming regression) were performed. The 95% confidence interval (CI) bands for the Bland–Altman analysis between the methods were −4.19 and 13.11, and the mean difference was 3.7e−12. The Passing–Bablok regression had a slope of 0.8 and an intercept of 7.6. The slope of the Deming regression was 0.8 within the CI bands of 0.56 and 1.10. These results show acceptable performance and no significant deviation from linearity. Hence, the results demonstrated the feasibility of HSI as an indirect alternative to the standard chemical analysis of PPO enzyme activity.

Shelf life assessment of fresh green pesto using an accelerated test approach

Abstract The shelf life of fresh green pesto, a traditional Italian sauce, was determined by analysing the evolution of the most important chemical, physical, microbiological and sensory quality attributes during its refrigerated storage at 4, 8 and 12 °C. Colour changes (greenness parameter a*) were fitted by applying an apparent zero-order equation, thus showing strong dependence on temperature. Peroxide values (PV) and thiobarbituric acid (TBA) values, fitted by applying an apparent first-order equation, increased with increasing storage time. The sensorial results were the most restrictive criterion, rather than microbial spoilage, and their shelf life values at ±95 % confidence limits were calculated from Weibull's distribution. Taste and overall acceptability scores of fresh green pesto showed high correlation with PV. The temperature dependence of quality deterioration was adequately modelled by the Arrhenius equation. The Q10 value (shelf-life at T°C/shelf-life at T+10 °C) and Ea (activation energy) for PV deterioration of fresh pesto sauce were 3.2 and 77 kJ/mol, respectively. Correlation between a chemical indicator parameter (PV) and sensory probability of product failure was evaluated, and a shelf life plot of fresh green pesto was obtained in order to estimate the shelf life of the product at different refrigerated storage conditions.

Chemical composition, Rheological, Organoleptical and Quality Attributes of Gluten-Free Fino Bread

Preparation and evaluation of acceptable gluten-free Fino bread (pearl millet, rice and corn flours) were targeted. Rheological properties of six blends were determined by Mixolab and Alveograph. Sensory evaluation of bread samples was done by ten mothers. The most acceptable samples were selected for chemical, antioxidant, texture, physical, microbial analysis and sensorial evaluation by 20 celiacs from Abu-Rish children’s hospital. Pearl millet flour has high protein and fiber (12.11 and 2.92 %, respectively), low carbohydrate (77.88 %), high minerals content, high antioxidant activity (55.31 %), high phenols and flavonoids (474.29 mg Gallic/100 g and 80.43 mg quercetin/100g, respectively) compared to corn or rice flours. High dough stability was in the M.R.RS blend (34 g millet, 34 g rice and 32 g rice starch). The highest P (resistance to extension), and the lowest L values (dough extensibility) were found in the M.R.C.RS blend (23 g millet, 23 g rice, 23 g corn and 31 g rice starch). Mothers preferred M.R.RS.E bread (M.R.RS+18g Egg), while their children preferred the same formula without egg (M.R.RS). The M.R.RS.E sample had the highest protein, fiber and mineral (Ca, Zn) contents. It was the largest specific volume (3.41 cmᶾ/g) and high freshness (404.89). This work achieved the goal by making acceptable gluten-free Fino bread using local materials with appropriate nutritional value for celiac patients.

Quality attributes and shelf life assessment of black pomfret (Formio niger) steaks treated with salts of organic acids

The main objective of this study was to assess effects of food grade sodium acetate and water dip as control treatments on the chemical, physical and sensorial quality attributes of decapitated black pomfret (Formio niger) during chilled storage at 4 °C for 7 days. Results indicated that control fish samples have been shown to lose texture, and show a gradual deterioration in quality attributes with chilled storage. The rates of these deteriorations are increased as the time of storage progressed. On the other hand, Sodium acetate treated fish samples exhibit higher moisture retention, tenderness, and bound water at any given time of chilled storage as compared with control samples. The present data also demonstrate lower values of drip loss, TVB-N and TMAN, are recorded in sodium acetate-treated samples. Analysis indicated that chemical, physical and sensorial quality advantages have been resulted from soaking black pomfret (Formio niger) in chilled temperature at 2.5% Sodium acetate solution for 5 minutes prior to freezing. Organic acid treatment can be an alternative way to improve the quality of decapitated black pomfret (Formio niger) during chilled storage. We can conclude that, sodium acetate dip treatment is for the maintenance of the functional properties of the seafood proteins which helps the preservation of the muscle integrity.

Chemical composition, safety and quality attributes of traditional cottage sausage

The characteristic features of traditional cottage sausage were analysed. In addition, the extent to which manufacturers create product diversity on the market was investigated, along with potential health risks of the product to consumers. The samples had high overall sensory scores. The average level of fat slightly exceeded 28%, cholesterol content was in the range of 435.4–1220.3 mg/kg and salt content was 1.53–2.77%. Some manufacturers do not cure their product, but about 20% of them apply nitrites above the level of 150 mg/kg. Due to their relatively high pH level (5.76–6.60) and water activity (0.95–0.98), Polish cottage sausage can be a medium which encourages the growth of microorganisms; however, pathogenic bacteria were not found. Histamine was detected in only 42% of the samples, at the low level of 2.6 to 34.2 mg/kg. Principal Component Analysis (PCA) was applied and the dominant variables were specified for particular PCs.

Chemical Composition and Quality Characteristics of Meat in Three One-Humped Camel (Camelus dromedarius) Breeds as Affected by Muscle Type and Post-Mortem Storage Period.

Simple SummaryThe present study aimed to investigate the influences of muscle type and postmortem storage period on meat chemical composition and quality attributes of three breeds of camels, including Baladi Saudi, Pakistani, and Somali. Baladi Saudi and Pakistani had better carcass characteristics than Somali. In addition, the longissimus lumborum muscle had better meat quality and the storage process can enhance quality features of meats that have relatively small amounts of connective tissue and that have not cold-shortened.The influence of muscle type and postmortem storage period on meat chemical composition and quality attributes of three breeds of camels (Baladi Saudi, Pakistani, and Somali) were investigated in this study. Crude fat and ash content were significantly higher in the Pakistani than in the Baladi Saudi and Somali breeds, except for higher moisture content observed in the Somali breed. The longissimus lumborum (LL) and semimembranosus (SM) muscles had a greater crude protein than the biceps femoris (BF) muscle. Storage period exhibited a significant reduction in pH values and improvement in color components of meat. The Somali breed produced higher cooking loss % and shear force, with a lower water holding capacity than the Baladi Saudi and Pakistani breeds. The LL muscle had better cooking loss %, water holding capacity, and shear force, whereas storage period (7 days) exhibited a significant reduction in the myofibrillar fragmentation index. Baladi Saudi and Pakistani breeds and LL muscle samples presented better meat sensory attributes, while storage period had no significant influence on the overall sensory characters of meat. In conclusion, there were significant differences between the chemical and structural characteristics of the LL, BF, and SM muscle samples among the three breeds of camel. Baladi Saudi and Pakistani had better meat quality traits than the Somali breed. In addition, LL muscles had better nutritional values and meat quality parameters than BF and SM muscles. Improvement in meat quality attributes were achieved with the storage process of 7 days. It is observed that, the Saudi Baladi camels have a merit of low fat content over both Somali and Pakistani camel breeds. It is also concluded that no significant effects were observed between the treatments as a result of storage when sensory attributes were considered. Moreover, breed, muscle and storage period were interacted significantly only with regard to lightness color space and shear force. This is useful knowledge for the meat industry for optimizing processing and storage procedures for various camel muscles.

Chemical quality attributes of mandarin (Citrus reticulata Blanco) as affected by altitude and fruit bearing position in Kavre, Nepal

Chemical quality attributes of mandarin (Citrus reticulata Blanco) as affected by altitude and fruit bearing position in Kavre, Nepal

Physical and Chemical Attributes of Pomegranate (Punica granatum L.) Cultivars Grown in Humid Conditions in Georgia

Pomegranate (Punica granatum L.) is a nonclimacteric fruit sold fresh as whole fruit or arils (fleshy seeds). It is also used for the production of juice, wine, and syrup. Pomegranate is popular due to its numerous health benefits. In the United States, it is grown primarily in California and other semi-arid regions, with Wonderful being the most widely grown cultivar. However, preliminary research has shown that ‘Wonderful’ produces low yields in Georgia, thus indicating the need to identify cultivars better suited for warm and humid conditions, such as those of the southeastern United States. The objective of this study was to determine the physical and chemical quality attributes of pomegranate cultivars grown in Georgia. Pomegranate fruit from 40 cultivars were harvested during 2012 to 2017. Individual fruit weight varied from 124 g for ‘Utah Sweet’ to 631 g for ‘C1’. The total fruit weight percentage accounted for by fresh aril weight (aril fraction) ranged from 22% for ‘C8’ to 70% for ‘JC’. Individual aril weight ranged from 174 mg for ‘Utah Sweet’ to 638 mg for ‘Cloud’. Across cultivars, individual fruit weight increased linearly with the increasing number of arils. Aril color varied from white to deep red. The arils L* value ranged from 15.7 (dark arils) for ‘Crown Jewel’ to 46.1 (light arils) for ‘Utah Sweet’. The a* values ranged from 0.6 (white arils) for ‘Cloud’ to 20.5 (red arils) for ‘Crab’. The b* values ranged from 8.7 for ‘DJ Forry’ (from a store) to 62.5 for ‘R9’. The Chroma* values ranged from 13.4 for ‘Cloud’ to 24.3 for ‘Crab’. The hue° values ranged from 29.7 for ‘Wonderful’ (from a store) to 87.1 for ‘Cloud’. Rind color was related to the color of the arils; high a* values in the rind and arils were associated with the red color. The fruit juice content ranged from 174 mL·kg−1 fruit for ‘Utah Sweet’ to 638 mL·kg−1 fruit for ‘Cloud’. Cultivars varied from tart to sweet. The fruit soluble solids concentration (SSC) ranged from 10.8% for ‘Sin Pepe’ to 16.4% for ‘Crown Jewel’. Fruit titratable acid (TA) ranged from 0.27% for ‘Sin Pepe’ to 6.20% for ‘Utah Sweet’. The juice maturity index measured as the SSC/TA ratio ranged from 1.9 for ‘Utah Sweet’ to 39.5 for ‘Sin Pepe’. The juice total phenols (measured as gallic acid equivalents) ranged from 463 mg·L−1 for ‘JC’ to 2468 mg·L−1 for ‘Wonderful’ (Georgia). Trolox equivalent antioxidant capacity values of juice ranged from 10,001 µM for ‘King’ to 59,821 µM for ‘I11’. Cupric reducing antioxidant capacity values in juice ranged from 7471 µM for ‘Azadi’ to 20,576 µM for ‘Wonderful’ (Georgia). Juice total anthocyanins varied from 1.7 mg·L−1 for ‘R19’ to 50.0 mg·L−1 for ‘Wonderful’ (Georgia). Pomegranate cultivars showed large variability in physical and chemical attributes. Such pomegranate variability represents opportunities for breeding, for the retail market, and for the development of different products by the food industry.

LOCAL regression applied to a citrus multispecies library to assess chemical quality parameters using near infrared spectroscopy.

The non-destructive on-tree measurement of the chemical quality attributes of fruits belonging to the Citrus genus using rapid spectral sensors is of vital interest to citrus growers, allowing them to carry out a selective harvest of any species of Citrus fruit. With this objective, the viability of using of a handheld portable near infrared spectroscopy (NIRS) instrument to predict soluble solid content (SSC), pH, titratable acidity (TA), maturity index and BrimA, in order to measure the optimum harvest time in a group made up of 608 samples belonging to the Citrus genus (378 oranges and 230 mandarins) was evaluated. For each of the parameters analysed, both non-linear regression (LOCAL algorithm) and linear regression (Modified Partial Least Squares, MPLS) strategies were designed and compared. The use of the LOCAL algorithm in the sample group of oranges and mandarins for all the parameters analysed allowed to obtain more robust models than those obtained with MPLS regression, and it could also be extended more easily when routinely applied. The results confirm that NIRS technology combined with non-linear regression strategies such as the LOCAL algorithm can indeed respond to the needs of the Citrus growers and help them to set the optimum harvest time, in this case of oranges and mandarins, by predicting the chemical quality parameters in situ.

Effects of Aloe vera gel and MAP on bioactive compounds and quality attributes of cherry laurel fruit during cold storage

This study was conducted to determine the effects of Aloe vera (AV) and modified atmosphere packaging (MAP) on physiological and chemical quality attributes of cherry laurel (Prunus laurocerasus L.) fruit during the cold storage at 0 ± 0.5 °C and 90 ± 5% RH. Throughout the storage, fruit weight and firmness losses were delayed with AV and MAP treatments. At the end of storage, the respiration rate of fruit treated with MAP was lower than the control and AV-treated fruit. Similarly, ethylene production of MAP and AV-treated fruit was lower than the control. At the end of storage, the highest hue angle was obtained from the control, whereas the lowest hue angle was measured in AV + MAP. Decay rate of AV and MAP-treated fruit was lower than the control. Vitamin C, total flavonoids, total monomeric anthocyanin and antioxidant activity of fruit treated with AV and MAP was higher than the control. The astringency of AV and AV + MAP-treated fruit was higher than the control at the end of storage. This study revealed that AV gel and MAP treatments were effective in maintaining quality and bioactive compounds of cherry laurel fruit.

Effect of some Inorganic NPK Fertilization Treatments on Cauliflower

Two successive winter field experiments were performed at 2015/2016 and 2016/2017 seasons at Vegetables Research Station, Faculty of Agric., Mansoura Univ., Egypt to study the effect of different fertilization treatments in terms of NPK fertilizer ratios and rates on growth, yield and quality of cauliflower (cv. Fargo) cultivated under silty clay loam soil conditions by furrow irrigation system. Four NPK fertilizer ratios (1.0:1.0:1.0; 1.0:1.0:0.5; 1.0:0.5:1.0 and1.0:0.5:0.5) with three fertilizer rates (50, 100 and 150 kg fed-1) as a soil application were tested. Each experiment comprised of 12 treatments and were designed as split plots and replicated three times in a randomized complete blocks design. The obtained data of this investigation clearly demonstrated that, all studied parameters such as vegetative growth characters (i.e., plant height and leaves number, plant leaf area, leaves fresh weight and leaves dry matter percentage), leaves chemical composition (viz. N, P, K, chlorophyll a, chlorophyll b and carotenoids contents), Curds yield and its components (i.e. curd weight, curd diameter, curds yield/fed. and curds dry matter percentage) and curds chemical quality attributes (namely, Vitamin C, TSS, N, P and K contents) had significantly been influenced with NPK fertilizer ratios, rates and their interactions in both seasons. Concerning the effect of NPK fertilizer ratios, 1.0:0.5:1.0 ration gave the highest values for all forecited characters, whereas 1.0:1.0:0.5 ratio recorded the lowest values in this respect. Regarding the impact of NPK fertilizer rates, the rate of 150 kg fed-1 achieved the maximum records for all mentioned parameters compared with other two fertilizer rates. Respecting the influence of interaction treatments, both commercial inorganic NPK fertilization treatments resulted from whether fertilizer ratio of 1.0:0.5:1.0 or 1.0:1.0:1.0 combined with 150 kg fed-1 fertilization rate recorded the best means for all aforementioned studied traits as compared with other all NPK fertilization treatments in this regard. Hence, it could be recommended that fertilization of cauliflower crop (cv. Fargo) with commercial inorganic NPK fertilizers blend resulted from combination of NPK fertilizer ratio 1.0:0.5:1.0 with the fertilization rate of 150 kg fed-1 in order to obtain high parameters of vegetative growth, yield and quality under similar research conditions.