eChapters

Abstract

Application of ultrasound is one of the most promising uses of novel technologies in food processing. Use of ultrasound at various stages of drying has resulted in significant decrease in drying time and improvement in quality characteristics of dried products. The chapter discusses the principle behind use of ultrasound, general application in food industry with detailed description of various drying processes and equipments assisted by ultrasound.

ABSTRACT

Fruits and vegetables are rich source of bioactive compounds such as polyphenols, antioxidants and flavonoids. Drying is one of the common methods for preservation of food and agricultural commodities. However, drying may negatively affect the product quality attributes. This article is a capsule overview of current state of art ultrasound (US) assisted drying on technical aspects and bioactivity of fruits and vegetables. US assisted drying is an economical and sustainable technique compared to other existing conventional techniques used for food processing and preservation. US as a pretreatment before drying of agricultural-products enhances drying efficiency, inactivate enzymes and improve overall quality of dried products. Current developments and available solutions in drying have shown that US assisted drying may be used to restrict the loss of crucial bioactive components occurring naturally in fruits and vegetables. US when combined with hot air drying helps in achieving adequate drying rate at lower temperatures and improves overall dehydration process. This technique has found no practical application commercially due to various difficulties in achieving high-intensity US in air. One practical benefit of using US assisted drying is the minimization of the drying time along with reduction in total energy consumption.

Ultrasound is an excellent diagnostic modality for detecting visceral abnormalities. Detection of masses, nodules or effusions through sonography provides non-specific diagnosis. For specific/definite diagnosis tissue samples are necessary for histopathological examination. The techniques of ultrasound guided fine needle aspiration and core biopsy are of great help in establishing etiological diagnosis.

During last two decades significant advances have been made in diagnostic ultrasound .These advances have positively impacted on diagnostic imaging across all species of animals and have made ultrasound as an indispensable diagnostic modality in veterinary medicine. Since equines have been more a sport and pack animals, the ultrasound technique has long been utilized in the diagnosis of equine musculo-skeletal disorders. Recent years have witnessed its utility in the management of equine reproduction beside its use in the diagnosis of colic and other diseases.

Ultrasonography is being routinely practiced in canine and feline medicine for the diagnosis of diseases of the organs and also to confirm pregnancy. Its routine use in ruminant medicine is mainly restricted to pregnancy diagnosis. Recently the potential of ultrasonography is also being explored in zoo and wild animals as well as in exotic pets. Information available in companion and other domestic animals cannot be applied blindly to zoo and wild animals.

For the sake of convenience ruminants are broadly divided into two categories as large ruminants and small ruminants. Large ruminants consist of cattle and buffaloes and small ruminants consist of goats and sheep. Sonography is becoming an important part of diagnostic modalities in ruminants also. Its major use in ruminants is in reproduction and lameness.

Imaging of muscles, tendons, joints and bones is not common practice in canine and feline medicine. However, scanning of tendons and ligaments is extensively done in race horses to see their fitness. Adhesions, ruptures/ tears and inflammation of tendons and ligaments can be detected by sonographic imaging of these structures. These structures are relatively superficial so a high frequency linear or curvilinear transducer (7.5 to 13.0 MHz) is used to scan these structures. For scanning of joints acoustic window is relatively small so micro convex or sector probes are more appropriate.

Sonography of the nervous system in dogs dates back to 1972 when it was employed in experimental studies. Thick bony cage of the brain limits the sonographic evaluation of the brain. It has an important place in human paediatric medicine. Sonography of the brain and the nervous system is not very common in veterinary medicine.

Ultrasound and survey radiography are two important diagnostic modalities regularly employed in the diagnosis of intestinal diseases. Both modalities are complementary to each other in investigating the problems related to intestines. It is always better to have plain survey radiograph of abdomen first and then ultrasound to rule out obstruction or radio-opaque foreign bodies. Wherever barium meal radiograph is indicated, it should be done after sonographic examination as barium may degrade image quality of the sonogram. Assessment of intestinal motility can be done in real time sonography.

Liver is situated in cranial abdomen. Scanning of abdomen is started with the examination of liver. Hepatic ultrasonography is a non-invasive diagnostic modality to evaluate liver parenchyma. Differentiation of focal disease from diffuse disease, cystic lesions from solid masses, and obstructive jaundice from non-obstructive jaundice is possible by hepatic ultrasonography.

The pancreas is a thin and elongated ‘V’ shaped organ having two lobes (right and left) and body. It lies in the right cranial quadrant of the abdomen. It is difficult to visualize normal pancreas sonographically because of its echogenicity similar to that of adjacent mesentery and fat.

Application of ultrasonography has become a routine practice in canine and feline medicine to detect pregnancy, to ascertain foetal wellbeing, to ascertain live/dead status of the foetus, ovarian dynamics, and to diagnose reproductive ailments (uterine, ovarian,) in females. Sonography is also being preferred in males for the diagnosis of diseases of prostate gland, cryptorchid, and testicular diseases.

Spleen is an elongated solid organ located on the left side along cranial and ventral abdominal wall. The size of spleen is variable in dogs. The spleen is larger in German Shepherds and Greyhounds. In cats the spleen is smaller and has fixed size. It is parallel to greater curvature of stomach within greater omentum. The position of spleen in dogs is variable as it is only attached by gastrosplenic ligament.

Ultrasonographic examination of gastrointestinal tract is not very much rewarding in dogs because of gas in the tract but it is crucial for a correct diagnosis. Imaging of stomach plays a significant role in the diagnosis of gastric diseases such as gastric dilatation, gastric foreign bodies, pyloric outflow obstruction, or gastric tumours.

Beside heart, ultrasound of the thorax facilitates the imaging of lungs, pleura, mediastinum, chest wall and diaphragm. Sonographic examination of the heart is discussed in chapter16. Because of nearly total reflection of sound waves at gas interfaces (Fig. 176) thoracic ultrasound has limitations. Pulmonary and mediastinal lesions located deep are difficult to image. Peripheral pulmonary lesions and pleural fluid can be visualized.

Ultrasound has been used to image thyroid and parathyroid glands. It can assist in the diagnosis of hyperthyroidism and hyperparathyroidism in dogs and cats. Recently it has also been used to differentiate cases of primary hypothyroidism or euthyroid syndrome.

The urinary tract is the body’s drainage system. It includes kidneys, ureters, urinary bladder and urethra. Ultrasound is a most preferred imaging tool for the diagnosis of diseases of urinary tract not only in humans but also in dogs and cats. Little adipose tissue in urinary system of dogs makes the contrast between different planes and anatomical structures poor.

Veterinary ultrasonographer has to write report of ultrasonography in different animals. The proper ultrasound report writing is the moral duty of the vet ultrasonographer. The accuracy of diagnosis must be ensured. The poor resolution/quality of machine may lead to erroneous diagnosis. Therefore, veterinarian must ensure good quality of machine and proper diagnosis. The report might be different in different animals e.g. report writing about uterus will be different in bitch, cows, buffaloes, camel, horse, goat and sheep. However following might be guidelines in writing ultrasound report of uterus. fetus, endometrium

Uterus: Position of uterus, contents in the uterus, shape and size in initial pregnancy and infections, appearance of myometrium, thickening of uterine layers, presence or absence of fluied/pus/masses, left and right horns and their contents. Observations on the images of uterine fluid and its echoicity, membrane appearance in pregnant animals. Special attentions should be paid to endometrium.

Endometrium: Appearance and thickness; any growth on the surface of endometrium. Images of retained portion of placenta can be ascribed in the cases of retained placenta.

Ovary: Ovaries are scanned to assess cyclic structures, size, shape, its Position/ location and internal echo pattern of follicles. This echo pattern will indicate whether follicle is normal, cystic or with any other abnormalities of follclular f luid. Ultrasound reports also include shape and size of corpus luteum. In cows and buffaloes, presence of cavity, looseness/compactness of luteal cells are also mentioned.

Uncertainty : See information.

Underground economy : See black economy.

Underinsured : Refers to livestock which have some type of livestock health insurance, such as catastrophic care, but not enough insurance to cover all their health care costs.

Unemployment trap : When unemployed people who receive benefits, either from the goverment or from private charity, are deterred from taking a new job because the reduction or removal of benefit if they do will make them worse off. Also known as the poverty trap, it can be addressed, to an extent, by continuing to pay benefit for a while to unemployed people returning to work. (See welfare to work).

Unconventional feed ingredients are those feed ingredients that are less commonly used in formulations or whose nutritional properties and feeding value are less well understood. Hence, these feeds are not traditionally used for animal feeding either by farmers or by feed manufacturer.
Unconventional feed resources
Concentrates sources: These are mainly mangoseed kernel, neemseed cake, rubberseed cake, tamarindseed cake, tamarind seed kernel, tapioca waste, salseed cake, safflower cake, nigerseed cake, spent tea waste, mahua cake, karanj cake.
Tree leaves and fallen tree leaves: Banyan, peepal, mango, teak, bamboo, neem, gliricidia, banana, cassava, mulberry.
Other by-products: groundnut shell, paddy husk, maize cobs, bajra cobs, jowar cobs, husk of bengal gram, black gram, green gram, sugarcane tops, bagasse, water hyacinth, molasses etc.
Marine and aquatic waste: Fish waste, frog meal.
Starch industry waste: Maize germ, maize bran, maize gluten.
Brewery waste: Dried brewer’s grain (after extraction of malt)
Slaughter house by-product: Blood meal, meat meal, meat and bone meal, tankage.
Poultry industry by-product: Feather meal, offal meal/ poultry waste meal, hatchery waste.
High moisture agro-industrial by-products: vegetable and food processing residues, apple/tomato/pineapple pomace, citrus processing waste.