Fruit chemical composition

We have developed several examples of fruitful areas in this chemistry that demonstrate feasibility. As one might expect, a list of compounds related to the pnictates proposed in Table 14.4 as the trivalent pnictogens and trielides should yield compounds of similar chemical composition. However, we can think of these systems in a slightly different manner. We can imagine a different formula from that in the previous equations ... 

Askar, A. and El-Samahy, S.K., Chemical composition of prickly pear fruits, Dtsch. Lebensm Rdsch., 77, 279, 1981. 

Stability may be inherent or induced. In the latter case, the original system is in a condition of metastable or neutral eouilibrium. External influences which induce instability in a dispersion on standing are changes in temperature, volume, concentration, chemical composition, and sediment volume. Applied external influences consist of shear, introduction of a third component, and compaction of the sediment. Interfacial energy between solid and liquid must be minimized, if a dispersion is to be truly stable. Two complementary stabilizing techniques are ionic and steric protection of the dispersed phase. The most fruitful approach to the prediction of physical stability is by electrical methods. Sediment volumes bear a close relation to repulsion of particles for each other. 

The early development and present status of petroleum oils as insecticides for use on deciduous fruit trees are reviewed. The biological groups of insects most susceptible to oil sprays are listed. Factors affecting oil deposit are discussed and data are cited to establish relationships between oil deposit and control. The relationship between chemical composition and control efficiency is also discussed. The possible modes of action by which petroleum oils kill insects are considered. Specifications are given for improved dormant spray oil. Current recommendations ifor the use of oil sprays in control of fruit pests occurring in New York State are listed. The possibility of developing more effective hydrocarbon insecticides is discussed. 

Chapman, Pearce, and Avens (4, 20) investigated the relation between chemical composition and insecticidal efficiency of various dormant and foliage spray oils against several common insect pests of deciduous trees, and found it to be positive. They concluded that an oil which is highly paraffinic in character is the most desirable type. Saturated narrow-cut petroleum fractions were used by Pearce, Chapman, and Frear 21) in a study of the influence of molecular weight and structural constitution on the insecticidal efficiency of such oils to eggs of the oriental fruit moth, Grapholitha molesta (Busck). Correlations between efficiency and various properties were compared on the basis of composition. The value of paraffinicity was illustrated, and the importance of other properties was indicated. 

The analyses of the flavour composition of yellow passion fruits were performed by four dilferent isolation techniques, namely vacuum headspace sampling (VHS), the dynamic headspace method, simultaneous distillation and extraction at atmospheric pressure, and simultaneous distillation and extraction under reduced pressure [62]. Significant differences were found not only in the chemical composition of the resultant extracts but also in their sensory properties. The most representative and typical extract was obtained by VHS. 

The world of aroma compounds is becoming more and more complex. In the early days people used aromatic products like fruit juices or fruit juice concentrates which were relatively weak and still close to the related foodstulf. Later, with more knowledge of separation techniques, infusions, extracts, oleoresins and absolutes ranging from weak to strong impact were used to impart aroma. Essential oils such as spice oils already had a very strong impact. Modern analytical technologies allowed the evaluation of the chemical compositions of extracts and essential oils, so that isolates either as powerful mixtures or even as single compounds could be obtained. 

Early studies of Concord and other native grape juices (7, 8) found soluble solids content of these juices in the 12°-20° Brix range and found them to be variable with location and season. The chemical composition of New York State grapes and juices was studied in 1938-1939 ( 9). Brix of Concord juice from ripe fruit from different areas within the state ranged... 

The overall chemical composition of brandy is derived from four general sources the fruit, alcoholic fermentation, distillation, and aging in wood. The scope of this discussion is limited to chemical aspects of the components of wine and their behavior during distillation. 

Many of these so-called natural products were first used without any knowledge of their chemical composition. As organic chemistry developed, though, chemists learned how to work out the structures of the compounds in natural products. The disease-curing properties of limes and other citrus fruits, for example, were known for centuries but the chemical structure of vitamin C, the active ingredient, was not determined until 1933. Today there is a revival of interest in folk remedies, and a large effort is being made to identify medicinally important chemical compounds found in plants. 

Investigation into the chemical composition of citrus has led to the isolation and identification of hundreds of individual compounds. As work has continued, biochemical, nutritional and organoleptic studies have made great strides in determining which compounds are paramount in the final determination of fruit and fruit product quality. For the purpose of this discussion, we will concern ourselves with only those quality aspects affected by endogenous chemical composition and consideration of physical or descriptive parameters will be omitted. 

In citrus fruits and products, most flavors and aromas are produced by polyphenolic compounds or essential oils plus a variety of non-volatile organic compounds. For detailed discussions of citrus flavors and chemical composition, the reader is referred to the excellent and comprehensive reviews which have been published (1,.2,.3,A.) ... 

Regulate the chemical composition of plants and the color of fruit. 

Hungarian studies have shown that the pericarp has 16-17% protein and the seeds contain 18% protein. When the microelements were investigated it was found that iron was present in the largest concentration, followed by bromide and manganese. Other microelements found were cadmium, calcium, cobalt, copper, magnesium, phosphorus, potassium, sodium and zinc. Fruits of the Capsicum species have a relatively low volatile oil ranging from about 0.1 to 2.6% in paprika. The characteristic aroma and flavour of fresh fruit is imparted by the volatile oil (Pruthi, 2003). The comparative chemical composition of chilli and paprika is given in Table 14.2. 

El Saeid, H.M. (1995) Chemical composition of sweet and hot pepper fruits grown under plastic house conditions. Egyptian Journal of Horticulture 22(1), 11-1 8. 

The approximate chemical composition of olive fruit is as follows water 52.4% oil 19.6% proteins 1.6% sugars 19.1% cellulose 6.8% and ash 1.5%. Oil yield and quality depend on the cultivar of olive tree, ratio of the various anatomical parts, and levels of minor components as well as growing conditions and health of the trees. Soil moisture is very important during fruit development. 

Palm oil is an edible oil referred to by the FAOAVHO Codex Alimentarius (1) as being derived from the fleshy mesocarp of the oil palm fruit. In the unprocessed form palm oil is reddish brown in color, and it has a semisolid consistency at ambient temperature. Readers should not confuse palm oil with palm kernel oil, which is another product obtained from the kernel of the oil palm fruit while palm oil is derived from the mesocarp or fruit flesh. The two oils have different chemical composition and physical characteristics, and they are used and marketed separately according to their own supply and demand situations. 

Rose, Rosa canina L., also known as dogberry or hop fruit, is in the Rosaceae family. The fruit of this particular species of rose is generally used to prepare a stew. The seeds from Rosa canina L. were investigated for their chemical composition and nutritional values for medicinal purposes. Seed oils were prepared from fruits grown at three locations in Turkey and evaluated for their fatty acid composition (31). Linoleic acid was the primary fatty acid detected, which ranged from 48.6-54.4% of total fatty acids, followed by a-linolenic acid (16.4-18.4%) and oleic acid (14.7-18.4%) (Table 4). The seed oil contained approximately 85% total unsaturated fatty acids, indicating that Rosa canina L. seed oil may be an excellent source for unsaturated and essential fatty acids. 

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