This study was carried out for chemical composition, phosphorus fractions, polyphenolic compounds, some minerals and thermal properties of starch in white dent maize whole flour (Variety Single Hybrid Giza 10) as affected by boiling, soaking and nixtamalization. The results of chemical composition showed that the UM flour had the highest contents of ash (1.46), oil (4.93) and caloric value (404.25 kcal/100g). Also, there were significant differences between the control and the treated samples, either increase or decrease in the contents of protein, crude fiber and total carbohydrates, which varied between 8.09-9.84%, 2.96-3.71% and81.22-83.85% for all studied samples, respectively. The phosphorus factions in maize samples were studied. From the obtained results, there were highly significant decreases in the values of total phosphorus (Tp), phytate phosphorus (Pp) and phytic acid in treated maize samples. The phytic acid content in the treated samples decreased significantly with percentages from 5.63% to 54.08% due to the nature of the treatment itself. There was a significant decrease in the total and bound phenolic contents of all the treated samples due to boiling, soaking and nixtamalization, with values ranged from 242.38 to 298.63%; from 233.87 to 292.32% when compared with control values 307.38% and 302.01%, respectively. The boiling, soaking, nixtamalization process significantly increases the calcium content of maize samples except BM30min it decreased. The starch content of studied samples was ranged from 55.81% to 69.83%. The gelatinization temperatures and enthalpies varied significantly between whole maize flours under study. The onset temp (To) was ranged from 30.56 to 42.37°C,while peak temp (Tp) ranging from 70.83 to 80.56°C as compared to 40.98°C and 80.56°C for Um sample, respectively. The HP content ranging from 3.76 to 4.38J.g for all the studied flours with small significant1difference between the treated and Um sample. From these results it concluded that treated whole maize flour has a good quality which better than untreated in processing of bread.

Key words: Starch, DSC, Total Carbohydrates, Polyphenolic Compounds and Whole Flour

One of the major physiological disorders for pomegranate cultivation is the excessive of fruit cracking. lately, a pomegranate physiological syndrome called ‘aril paleness’ in which a part or all of the arils appear discoloration, affect the quality of fruit and such fruits are not desired for consumer. The present research designed to evaluate the effects of methyl jasmonate (MJ), humic acid (HA) and potassium (K) on reducing these disorders and improving fruit quality. Seven treatments including MJ (5 and 10 ppm), HA (50 and 100 ppm), Liquid K (1 and 2%) and control, were tested on pomegranate trees spraying three times, at the beginning of flowering (during April), after full bloom (end of June) and before harvesting (mid-September), during the two seasons of study. Different parameters including yield, fruit cracking and fruit quality were measured. The obtained results indicated that spraying HA at 100 ppm and MJ at 10 ppm are considered the best in their effects on the yield components, fruit quality and anthocyanin content, however for decreasing the fruit cracking, it could be recommended to spray the fruits with K at 1% or MJ 10 ppm compared to the rest of the treatments.

Grapefruit is considered a fruit of good nutritional value provide us with many useful nutrients and has many benefits in the food processing. Also the grapefruit peels contain innumerable nutrients and used in the making of jam and desserts. The current study aimed to utilize the whole grapefruit peels flour in cake fortification. Study included determination of gross chemical composition, caloric value, physical, sensory properties of the studied cakes likewise; staling rate and loss of freshness of studied cakes were assessed. The data revealed that incorporation of both wheat flour and treated whole grapefruit peels flour (TGPF) increased moisture, ash and crude fiber to (25.51%- 28.45%); (3.95%-4.42%) and (0.81%-2.22%); respectively. The results showed that 5%, 10%, 15% and 20% TGPF had a different effect on all studied sensory and physical characteristics of all studied cakes. Moreover, cake with 5%, 10% TGPF was recorded the best scores of all studied sensory characteristics in fortified cakes. The staling rate mean values of the different cake samples were reduced gradually during storage for 2, 4, 6 and 8 days. The higher freshness (27.21%) was assessed in cakes fortified with 15% TGPF. The results showed that cake fortified with 20% TGPF had the highest staling value (362.20%) after 8 days of storage as compared to all other cakes samples. Consequently, it recommended utilizing the grapefruit peels to enhance the nutritional values of cake.

Key words: Grapefruit peels, Chemical composition, Cake Staling, Physical and Sensory Characteristics.

The storage temperature is one of the most important factors affecting on the fruit peels composition and quality after harvesting. The pink grapefruit (Citrus paradise L.) peels was subjected in current study to examine the effect of different storage conditions on phytochemical constituents, the antioxidant activity and constants of peels oil. The phytochemical constituents of the pink grapefruit peels such as lycopene, phenolics, flavonoids and vitamin C were assessed the level of their concentrations for examine their antioxidant activities and the effect of storage on those components. The antioxidant effects was determined from the changes in acid value, peroxide number, conjugated diene and triene contents and the delay of rancidity of pink grapefruit peels oil during storage conditions for 60 days in refrigerator temperature at 8 ±1°C and for 40 days in room temperature at 16± 4°C. Results of a proximate composition of pink grapefruit peels during storage conditions showed that significantly decreased (P ≤ 0.05) in moisture, carbohydrate and energy values at most storage periods. On the other side, Protein, fat, fiber and ash contents were significantly increased (P ≤ 0.05) in most different storage periods. The Antioxidants components such as:  Lycopene, total phenolics, and total flavonoids content; as well as, antioxidant activity of pink grapefruit peels were significantly increased (P ≤ 0.05) during storage conditions, while, ascorbic acid levels were significantly (P ≤ 0.05) decreased during storage periods at different storage conditions. The rates of increase in antioxidant activity of samples stored at room temperature were higher than in the refrigerator. The contents of peroxide number, conjugated diene and triene was significantly (p ≤ 0.05) increased for most storage periods at room temperature (16± 4°C), while, non-significant differences (p ≤ 0.05) were found during storage periods at refrigerator temperature (8 ±1°C). On the other hand, acid value was significantly decreased (p ≤ 0.05) after 20 days of storage at room temperature, while, non-significant differences (p ≤ 0.05) were found during storage periods at refrigerator temperature. The storage at refrigerator temperature (8 ±1°C) improved the shelf-life of pink grapefruit peels and to maintain health promoting compounds.

Key words: Grapefruit peels, Bioactive compounds, Antioxidant activity, Storage conditions, Peels oil properties.

Abstract

Experiment was carried out throughout two successive seasons of 2016 and 2017 on Flame Seedless, Ruby Seedless and Thompson Seedless grapevines grown at the Experimental Orchard of Assiut University, Faculty of Agriculture. The aim of this study was to assess the impacts of abscisic acid (ABA), cluster thinning and their combinations with GA3 on yield weight of three important grape cultivars grown under hot region. Data revealed that, the application of abscisic acid (ABA) increased yield weight (kg/vine), while cluster thinning decreased it. During the 1st season of study (2016), all individual ABA treatments and ABA at 400 ppm combined with GA3 at 10 ppm significantly increased yield weight (kg/vine) comparing with the control treatment. As a result of ABA treatments at 200, 400 and 600 ppm and ABA at 400 ppm plus GA3 at 10 ppm, the yield was increased by 15.5%, 10.5%, 9.8% and 9.2%, respectively. During the 2nd season of study (2017), only ABA at 600 ppm treatment significantly surpassed the control treatment with an increment percentage of 20.5%.  The rest of treatments either had no effect or reduced the yield weight comparing with the control. On the other side, cluster thinning by removing 30% of the total clusters that the vine bearing significantly reduced the yield weight (kg/vine) during the two studied seasons. As a result of such treatment, the yield was reduced by 37.2% and 39.2% in 2016 and 2017 seasons, respectively.

Keywords

grape; Vitis vinifera; ABA; Cluster thinning; yield