SELECT COUNT(*) c, p.product_id, (SELECT AVG(rating) AS total FROM #__mijoshop_review r1 WHERE r1.product_id = p.product_id AND r1.status = '1' GROUP BY r1.product_id) AS rating, (SELECT price FROM #__mijoshop_product_discount pd2 WHERE pd2.product_id = p.product_id AND pd2.customer_group_id = '1' AND pd2.quantity = '1' AND ((pd2.date_start = '0000-00-00' OR pd2.date_start < NOW()) AND (pd2.date_end = '0000-00-00' OR pd2.date_end > NOW())) ORDER BY pd2.priority ASC, pd2.price ASC LIMIT 1) AS discount, (SELECT price FROM #__mijoshop_product_special ps WHERE ps.product_id = p.product_id AND ps.customer_group_id = '1' AND ((ps.date_start = '0000-00-00' OR ps.date_start < NOW()) AND (ps.date_end = '0000-00-00' OR ps.date_end > NOW())) ORDER BY ps.priority ASC, ps.price ASC LIMIT 1) AS special FROM #__mijoshop_product_to_category p2c LEFT JOIN #__mijoshop_product p ON (p2c.product_id = p.product_id) LEFT JOIN #__mijoshop_product_description pd ON (p.product_id = pd.product_id) LEFT JOIN #__mijoshop_product_to_store p2s ON (p.product_id = p2s.product_id) WHERE pd.language_id = '1' AND p.status = '1' AND p.date_available <= NOW() AND p2s.store_id = '0' AND p2c.category_id = '28' GROUP BY p.product_id ORDER BY LCASE(pd.name), p.product_id DESC, LCASE(pd.name) DESC
The rate of syneresis of the rennet-milk coagulum was followed by adding skim milk, rendered non-coagulable by the addition of formaldehyde, to the coagulum just prior to cutting. The subsequent change in light absorption of this skim milk due to progressive dilution as syneresis proceeds is used to calculate the volume of whey expelled from the coagulum. Typical results obtained by this method for the syneresis of both whole milk gels and skim milk gels are given. The standard error of a single determination of whey-volume was 2.6 per cent for whole milk gel and 2.2 per cent for the skim milk gel. Syneresis proceeded at a greater rate with skim milk gel than with whole milk gel.
A method is described for routine monitoring of 'milk loss' in the permeate stream during UF processing of whole or skimmed milk. The simplicity and high sensitivity of the technique makes it a useful aid to membrane management. Soluble proteins in permeate are estimated separately from casein plus fat, using a more complex procedure.
The casein industry needs a routine fat test of reasonable accuracy and within the scope of the factory test room. Nothing of this type appears to have been devised since the field was reviewed by Sutermeister and Browne in 1939. The acid digestion methods modified fro Babcock flasks or butyrometers do not appear to have proved popular, possibly because of inaccuracy or slowness. The test here presented uses sulphuric acid, n-butyl alcohol and the Babcock skim-milk flask. It is sufficiently accurate to give a sound index of fat content for factory use.
Milk was wet-ashed with potassium dichromate and sulphuric acid to oxidize iodine to iodate which was then treated with phosphorous acid. The liberated iodine was distilled and trapped in ammonium hydroxide. Iodine in the distillate was determined by the selective oxidation of leuco-crystal violet to crystal violet by hypoiodous acid, formed by the action of N-chlorosuccinimide/succinimide on ammonium iodide. The method is simple, reliable and the colour developed is stable. The recovery of added iodine was 88% with a mean standard deviation of 7.5.
A method has been developed for the direct determination of calcium in casein by addition of excess ethylene diamine tetra-acetic acid (EDTA) and back titration with a standard calcium solution using "Calcon" as the indicator. The presence of phosphorus did not appear to affect the end point.
This paper highlights the problems of obtaining accurate quantitative Aschaffenburg and Mullen phosphatase test results for the monitoring of goat's milk pasteurization. It introduces a modification to the standard Aschaffenburg and Mullen method so that the detection of the lower levels of alkaline phosphatase in goat's milk can be enhanced. The modification allows the detection of underpasteurized goat's milk and raw goat's milk in pasteurized goat's milk at a similar level to that shown for cow's milk by the standard Aschaffenburg and Mullen method.
The short process of cheesemaking developed by the C.S.I.R.O and the Victorian Department of Agriculture has been modified by excluding the Streptococcus lactis and Str. cremoris. strains of starter culture from the manufacture. Satisfactory cheddar cheese has been using only active strains of Str. thermophilus. With the modified method a higher initial cooking temperature was employed. It was found that the pH of the cheese produced was commonly higher than that of the standard new was method, but eventually dropped to below pH 5.30. Regular acid development during the manufacturing process was found to be essential for food quality cheese.
A modified method is described for the rapid estimation of fat in casein. After treating the ground sample with a 3 per cent borax solution and the addition of amyl alcohol, digestion is effected with sulphuric acid of s.g. 1.825/15°C. The results obtained by the rapid method agree within approx. 0.2 per cent with those of the British Standard acid gravimetric method for acid and rennet caseins.
Full-cream milk powders stored at elevated temperatures for prolonged periods can be difficult to de-emulsify using standard methods. Pretreatment with sodium borate and a proteolytic enzyme resulted in release of the fat without a significant influence on the peroxide value.
The original Greiss-Llovsay method for detecting nitrate reductase activity of micro-organisms has been modified for daily routine milk quality control programs by (a) incorporating preliminary incubation of milk sample at 15°C ± 0.5°C for 22 h ± 1 h prior to further incubation at 30°C ± 1°C before subsequent reaction and colour development; (b) addition of penicillin prior to preliminary incubation for selection and gram-negative bacteria; and (c) substitution of the non-carcinogenic reagent alpha-naphthol for alpha-naphthylamine used in the original method.
Bacterial counts of flora, both total, as denoted by the standard plate count, and psychotrophic, were used in the determination of a suitable standard for the time of nitrate reduction (viz. greater than 5 hours).
Results reveal that the method as used and the standard adopted as suggested combine to form an efficient means of reflecting milks of poor bacterial quality.
Authors: Garth J.S. Cooper, Geraldine F. Keogh, Tom B. Mulvey, Brian H. McArdle, Alastair K.H. MacGibbon and Sally D. Poppitt
Current US guidelines recommend that less than 30% of dietary energy (en%) in adults should derive from total fats, in part to limit excessive intake of saturated fats, which is linked to atherosclerosis, obesity and some cancers. Dairy foods are a major source of saturated fats, so such guidelines effectively advocate decreased consumption of dairy products to 2-4 servings daily. Milk containing increased unsaturated fatty acids has been produced by feeding cows with a protected feed supplement rich in oleic acid. Feeding of butterfat derived from this milk elicited decreased blood LDL-C in two of three trials. To resolve ongoing uncertainty concerning the efficacy of butterfat per se, we have investigated its blood lipid-lowering potential in 20 healthy male subjects using a double-blind, randomised, intervention trial. During this residential trial, all foods and beverages were provided during two intervention periods, comprising 3 weeks of high unsaturated 'modified' vs. 3 weeks of saturated 'control' butter feeding separated by a 4-week washout period. Diets were of typical composition of 39 en% fat (20 en% butterfat), 48 en% CHO, 13 en% protein. There were significant decreases in both total (p<0.05, -7.9%) and LDL-C (p<0.01, -9.5%) during feeding of modified butter, but no significant changes in a range of other risk factors including HDL-C, TG, or fasting glucose (p>0.05). Subjects were maintained in energy balance with no significant change in body weight during interventions; butterfat composition alone differed between treatments. Thus, clinically significant improvement in cardiovascular risk can be achieved by moderate changes in dietary fatty acid profile achieved through a common and well-accepted food source, butterfat.
A scheme for the production of frozen bulk starter concentrate, based on the continuous culture of lactic streptococci, the centrifugal separation of the bacterial cells, and their freezing in liquid nitrogen, is outlined. Experiments have shown that a concentrated fluid suspension of Streptococcus lactis cells, equivalent to 20 gal. of bulk starter, would contain 3 x 1014 cells and would occupy a volume of about 400 ml. About 130,000 such cultures per year would be required to replace conventional bulk starters in Australian cheese factories.
pH-controlled fermentations in milk and whey have provided information on some of the factors which would affect the growth of lactic streptococci in continuous culture. The pH for maximum growth rate and population density was 6.3 and the optimum temperature 30°C. At pH 6.3 maximum direct microscopic counts of about 5 x 108 per ml were obtained in whey and 1 x 1010 in milk. The highest counts, exceeding 5 x 1010 per mil were obtained in cheese whey fortified with yeast extract and tryptone. At this level of count the concentration of sodium lactate is an important factor in limiting population density. It is estimated that with unfortified whey a fermentation volume of 420 gallons using 8,000 to 9,000 gallons of whey per day would be required for the continuous production of concentrated starters at the rate of 130,000 per year. With fortified whey the fermentation volume could be as low as 25 gallons and the rate of whey utilization 800 gallons per day.