THE EFFECT OF ULTRAVIOLET IRRADIATION ON SHELF-LIFE AND RIPENING OF PEACHES AND APPLES

“Loring” and “Elberta” peaches and “Golden Delicious” apples were irradiated with UV (254nm) to doses of 0.84 × 10⁴ to 40 × 10⁴ erg/mm² then stored. “Loring” were stored 10 days and “Elberta” 20 days at 12°C. “Golden Delicious” were stored 30 days at 20–25°C in a dark room. Fruit were examined and differences in percentage rot and in physical-chemical properties determined. Percentage rot decreased with increasing UV dose. Fruit were firmer, pH and soluble solids lower and acidity higher for UV-treated than for nontreated peaches; pH was lower and acidity and ascorbic acid higher in UV treated than in nontreated apples. Percentage weight loss was less for UV-treated apples. The results indicated that UV treatment not only reduced storage rots but also delayed ripening of peaches and apples.     

Cholesterol Content of Raw and Cooked Beef Longissimus Muscles with Different Degrees of Marbling

The relationships of marbling level (eight levels from “Moderately Abundant” to “Practically Devoid”) and cooking to cholesterol content of beef longissimus muscle steaks were studied. Only raw steaks with “Practically Devoid” marbling contained significantly less cholesterol (wet basis) than did raw steaks with any of the other seven marbling scores. However, steaks cooked to an internal temperature of 60° or 75°C showed no significant differences in cholesterol content among any of the eight marbling groups. The cholesterol content of cooked steaks was 22–48% higher than that of raw steaks when cooked to 60°C and 38–65% higher when cooked to 75°C; cooking reduced the weight of each steak, thereby increasing the cholesterol content of the steak expressed as a percentage of the cooked weight.     

The evaluation of liquid de-oiled herring silage in diets for growing pigs: Palatability studies

Triangle tests were used to detect possible differences in the aroma of subcutaneous fat of growing pigs receiving de-oiled herring offal silage as a protein supplement at high (HS) and medium (MS) levels, i.e. at levels of 150 and 75 kg t^?1 dry matter (DM), when compared with samples from matched controls. Tests were carried out on samples from pigs slaughtered at 60 and 90 kg. Statistically significant differences in the aroma of subcutaneous fat were detected at both feeding levels (HS and MS) and at each slaughter weight (60 and 90 kg). Correct identification of the odd samples was 60% in pigs slaughtered at 60 kg at both feeding levels. At 90 kg slaughter weight, there were 56 and 76% correct identifications at HS and MS levels, respectively. Paired Comparison (Preference) tests were used to determine if such differences were associated with flavour defects and consequent loss of palatability. Roasted pork joints and pork/rusk loaves from HS and MS pigs were compared with matched controls (HC and MC). As a result of these tests it was concluded that detectable differences from controls in aroma of subcutaneous fat in samples from HS and MS pigs were not associated with alteration in consumer preference for cooked meats. There was no evidence of taint in meats from either HS or MS groups.     

Relationships Between Sensory Attributes and Objective Measurements of Postharvest Quality of Tomatoes

Sensory and objective measures of postharvest quality of fresh market tomatoes were obtained before retail to the consumer. Effects of storage at 10°C and 21°C and differences in sensory quality of “ethylene-treated” versus “vine-ripened” tomatoes were determined. Principal component analyses of 19 variables reduced these to a maximum of six factors which explain 71% of the variance which could allow a reduction in the number of analytical tests. No objective measures other than firmness and color correlated with sensory measures. Except for color, sensory scores of Winter and Spring tomatoes were below the halfway point on the rating scale. Scores improved after storage at 21°C for 7 days. The only difference found in “ethylene-treated” and “vine-ripened” tomatoes was firmness “to the touch.”     

Electrical Stimulation and Hot Boning: Cooking Losses, Sensory Properties, and Microbial Counts of Ground Beef

Six batches of ground beef, approximately 10, 15, or 20% fat, were fabricated from flanks (lean and fat trim) of electrically stimulated-hot boned (ESHB) or conventionally chilled (CC) beef sides. Patties (2.5 × 7.6 × 8.2 cm) from each batch were modified broiled for 35 min at 177°C. Generally, ESHB and CC products were comparable in cooking and sensory properties and in microbial counts of raw products. ESHB products had slightly higher cooking losses, more intense beef flavor, and were slightly juicier than CC products. Small differences between ESHB and CC products more often were attributable to fat content than to processing treatment (ESHB or CC).     

Cholesterol reduction in camel hump fat using ��-cyclodextrin

??-Cyclodextrin (??-CD) was used for removing cholesterol from fatty tissues such as lard, milk fat. This investigation was carried out to study optimum conditions of different factors (??-CD concentration, stirring temperature, stirring time, stirring rate and ratio of hump camel fat to water for reduction of cholesterol in hump camel fat by application of ??-CD and resulting changes in cholesterol reducing camel hump fat). ??-CD concentration at 1?C10% provided about 88.89?C95.3% removal of cholesterol when mixed at 40°C for 91?h. Among other factors, mixing time (0.5?C2?h) did not significantly affect cholesterol reduction. Removal was enhanced with increasing stirring rate to 800?rpm and centrifugal forces up to 5,000×g (95.5%) but decreased thereafter. The obtained results showed that the optimum conditions for the process were addition of 7% ??-CD, 40°C mixing temperature, 1?h of mixing time, the ratio of camel hump fat to water 1:1, and stirring rate 800?rpm and centrifugation at 5,000×g. The acid value of ??-CD treated camel hump fat was significantly decreased due to removal of free fatty acid. The peroxide value of ??-CD treated camel hump fat was slightly increased. No significant differences were noted in the fatty acids composition between treated with ??-CD and untreated camel hump fat.     

Einflüsse von Braten und Grillen auf Fettqualität,Zartheit und Zusammensetzung von Schweinekoteletts aus verschiedenen Markenfleischprogrammen

Differences in fat quality, tenderness and composition of raw, roasted and grilled pork loin chops obtained from different meat brands Three loin chops obtained from each of a total of 180 pigs within one slaughter house either were left raw or were roasted at 120 °C for 12 min or simultaneously grilled on both sides at 180 °C for 6 min, respectively. Four different groups of 45 animals each were employed: pigs of conventional origin, pigs from a meat brand basing on animal welfare principles (Neuland) and pigs from two sub-systems of another commercial meat brand (Pigour) among others using higher contents of medium chain fatty acids in the feed. With the less intensive roasting, lower cooking losses and shear forces were observed as compared to grilling. The final intramuscular fat content was almost twice as high as the initial value of 1.3% with both cooking procedures. In subcutaneous back fat, cooking resulted in a highly significant reduction of the proportion of the polyenic acids which, however, was of only low numerical extent. The induction period till fat oxidation was significantly increased by 25% with roasting and by 8% with grilling. The clear differences in the quality of the raw chops obtained from the different origins could be almost completely recovered in the cooked chops.     

Physiological Activity of Deep-Frozen Concentrates of Leuconostoc Strains

11 strains of Leuconostoc cremoris and 1 strain of Leuconostoc lactis were the subject of investigations. Basing on the evaluation of growth parameters in the different cultivation media and on the diacetyl production ability in milk 2 strains of Leuconostoc cremoris and 1 strain of Leuconostoc lactis were chosen for preparing frozen concentrated biomass. Sterile milk or cream (18% fat) were used as protecting agents. Concentrated biomass was frozen at ?70 °C and stored at ?30 °C for 3 months. The prepared concentrates contained from 1.6 × 10¹¹ to 2.8 × 10¹¹ colony forming units (CFU)/g. Except for one (strain “S”) the strains retained 100% survival. All the strains showed high growth activity after their recovery in milk (3.3 × 10⁸ - 8.4 × 10⁸ CFU/ml). Both protecting agents applied proved to be equally good for preserving viability of the cells and for their acidifying activity. In spite of the protecting agent a decrease in the aroma activity by 25–50% was observed after one month of the biomass storage. Nevertheless, concentrated frozen multicomponent starters containing Leuconostoc strains retained the ability to produce diacetyl and acetoin on the unchanged level during the three months storage period.     

Metabolites in golden delicious apples as possible parameters of acceptability

The ripening process of “Golden Delicious” apples, harvest 1972, during storage at 4 °C under controlled atmosphere, was assessed sensorially with a palatability test based on the attributes flavour, sweetness or sourness, and texture. After 130 days of storage 50% of the apples had flavour pertaining to ripe (pleasant to eat) stage and 50% pertaining to overripe (unpleasant to eat). The same proportions for sweet-sour relation (ripe and overripe) and texture (ripe and overripe) were reached after 180 days of storage, when fruits became clearly inedible. This showed that flavour was the first attribute to deteriorate and therefore it constituted the limiting factor of the internal quality of apples. Consequently the following criterion was adopted: the internal quality of a batch of apples remained satisfactory until the proportion of apples assessed as of ripe flavour (40–50 %) was similar to the proportion of apples with overripe flavour (40–50%). This moment coincided with the inflexion point in the graph of sucrose content per initial fresh weight of apples against time and with the fall of L-malate below about 0.40%. The inflexion point of the graph for citrate was earlier than the inflexion for sucrose.     

Manipulation of the fatty acid composition of pig meat lipids by dietary means

Pigmeat products have been associated with an unhealthy image due to the relative proportions of polyunsaturated and saturated fatty acids. The aim of this experiment was to improve the fatty acid profile of the carcass fat by feeding various dietary sources of fat. Groups of 10 female Large While × Landrace pigs were fed one of four experimental diets. Five in each group were slaughtered at 70 kg live weight and the remaining five at 100 kg live weight. The diets were offered ad libitum and daily intake was recorded. The diets were based on barley, soya bean meal and fishmeal. Diet 1 contained 50 g tallow kg^?1, a relatively saturated fat, and diets 2, 3 and 4 contained 50 g soya oil kg^?1, an unsaturated fat. Diet 3 also contained 7.5 g GLA oil kg^?1, which is rich in gamma linolenic acid, with the aim of increasing the production of arachidonic acid in the body fat. Diet 4 was supplemented with 9.5 g EPAnoil kg^?1, which is rich in eicosapentaenoic acid and docosahexaenoic acid. There were no significant differences between dietary treatments in performance (daily liveweight gain or the efficiency of food conversion to liveweight gain) of the pigs slaughtered at 70 kg live weight, but small differences were observed at 100 kg live weight, where pigs on treatments 2, 3 and 4 performed slightly better than those on treatment 1. At both slaughter weights the lipid content of the m semitendinosus was higher than that of the m longissimus dorsi (approximately 24 and 13 g kg^?1, respectively). The pattern of fatty acids in the dietary fat was reflected to varying degrees in the carcass fat. Diet 1 resulted in the highest levels of palmitic, palmitoleic, stearic and oleic acids whereas diets 2, 3 and 4 gave high levels of linoleic and linolenic acids. The extra gamma linolenic acid in diet 3 did not result in a consistently significant increase in the production of arachidonic acid. The supplement of EPAnoil gave significant increases in the levels of eicosapentaenoic and docosahexaenoic acids in the body lipids. The polyunsaturated to saturated fatty acid ratio of the body lipid was increased with diets 2, 3 and 4 to about 1.0. In spite of high levels of linoleic acid, there were no adverse effects during the processing of the carcasses and the taste panel evaluation did not reveal any treatment differences.     

Recent observations on the occurrence of fishy flavour in bacon

An examination of reject bacon samples supplied directly from a factory showed that some samples described by a sensory panel as oily and fishy contained significantly higher levels of long chain polyunsaturated fatty acids (PUFA) in their fat than normal samples. When bacon samples obtained from retail outlets were similarly analysed and then subjected to sensory assessment, those found to contain long chain PUFA were given significantly higher scores for oily and fishy flavour. Observations on the fatty acid composition of fishy bacon samples as compared to non-fishy ones and further investigation into the diets of pigs producing suspect carcasses led to the conclusion that too high a content of fish products in the diet was the main cause of the problem. Contrary to what had been believed, fresh non-fishy bacon samples did not develop fishy flavour after storage at ?20°C for 15 weeks. Perceived fishiness was not related to total copper content as determined by atomic absorption spectroscopy.     

高粱原花青素对生长育肥猪抗氧化、免疫以及养分消化率的影响

研究高粱原花青素(sorghum procyanidins,SPC)对生长育肥猪生长性能、养分消化率、消化酶活性、免疫力和抗氧化能力的影响。160头70日龄、平均体重为(31. 28±1. 12) kg的杜×长×大三元杂交猪,按照单因素完全随机设计分为4个组,分别饲喂玉米-豆粕基础日粮,以及基础日粮中添加100、150、200 mg/kg SPC。实验期为14周,生长期和育肥期各7周。在每个实验阶段开始和结束时称重,每天记录采食量,计算各阶段平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)。在每个实验阶段的最后3 d,收集粪样测养分消化率。在每个实验阶段结束时,采血测血清抗氧化指数和免疫参数,同时,每个重复随机屠宰2头猪,取胰腺组织,测消化酶活性。结果表明,日粮添加SPC对生长育肥猪的生长性能没有显著的促进作用(P 0. 05)。在生长猪阶段,日粮添加150 mg/kg和200 mg/kg SPC显著降低了消化酶的活性,对养分消化率有降低的趋势。在育肥猪阶段,日粮添加150 mg/kg显著提高了粗蛋白的表观消化率(P 0. 05),200 mg/kg SPC显著地抑制了消化酶的活性(P 0. 05)。与对照组相比,不论是在生长期还是育肥期,添加150 mg/kg或200 mg/kg的SPC均显著地增强了猪血清谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)的活性以及血清总抗氧化能力(T-AOC)(P 0. 05),降低了血清丙二醛(MDA)浓度(P 0. 05),提高了猪血清IgG、IgM和白细胞介素2(IL-2)的浓度(P 0. 05)。总之,SPC有利于提高生长育肥猪抗氧化能力,增强免疫力,但是对于生长育肥猪的生长性能及养分消化率没有显著的促进作用,相反,高浓度的SPC甚至抑制了消化酶的活性,从而影响养分的消化利用。     

Flavour release at gas/matrix interfaces of stirred yoghurt models

Release of strawberry flavour compounds at vapour/matrix interfaces was studied in model food systems simulating a yoghurt with a fruit preparation syrup. The effect of different parameters including physicochemical characteristics of the flavour compound, the structure and composition of the matrix and the temperature (4 and 10°C) on the release of the flavour compounds were investigated. There was an effect of the composition and structure of the matrix upon the partition of the flavour compounds. In the dairy gel, retention of flavour compounds was caused by the physicochemical interactions with the proteins and the solubilisation in dispersed fat. The addition of syrup to the low-fat dairy gel slightly increased the retention of the flavour compounds; this was attributed to physicochemical interactions with pectin and sucrose. In the presence of fat (5%), the flavour compounds were solubilised in the fat and their release was not affected by the composition of the dispersing medium. As expected, temperature affected the release; an increase from 4 to 10 °C resulted in an increase in the overall amount of flavour released.     

Use of healthier fats in biscuits (olive and sunflower oil): changing sensory features and their relation with consumers' liking

The aim of this study was to evaluate consumer acceptability of biscuits when saturated fat was replaced by olive or sunflower oil and to determine the sensory characteristics responsible for changes in acceptability. Ninety seven consumers evaluated the acceptability of six biscuit samples varying in the fat source (dairy shortening, olive oil and sunflower oil) and fat content (10.6% and 15.6%). Using a Check All That Apply question (CATA), consumers also evaluated sensory properties of biscuits. Results indicated that the replacement of saturated fat (dairy shortening) by vegetable oils had an effect on biscuit acceptability which depended on biscuit fat content. According to biscuits' acceptability data, three different clusters of consumers were identified. By using a multiple factor analysis, the relationship among sensory CATA data and acceptability of each cluster explained the different acceptability patterns of consumers. For most of consumers acceptability was related to attributes “crispy”, “easy to chew” and “biscuit flavour” which, for one group were perceived in shortening biscuits and, for another in both olive and shortening biscuits. However, for the third group of consumers, acceptability was only related to flavour attributes like “roasted flavour” or “biscuit flavour” that were perceived in vegetable oil biscuits which were the preferred biscuits while, shortening biscuits were disliked and perceived as having an “off flavour”.     

Bilateral Temperature Asymmetry in the Loin of the Bovine Carcass

Conflicting claims of the effects of early postmortem electrical stimulation on the temperature and cooling rate of beef were investigated, using an improved method of temperature measurement and a precise alternation of sides receiving the treatment. No stimulation effect on temperature was detected, but a consistent laterality effect was observed, the right loin on average being almost 2°C warmer than the left at 3 hr postmortem regardless of prior unilateral or bilateral stimulation. This temperature difference appears to be a localized phenomenon due to the asymmetric distribution and “tightness” of the kidney fat overlying the interior surface of the central loin area.     

Cadmium in meat and edible offal of free-range reared Swallow-belly Mangulica pigs from Vojvodina (northern Serbia)

The aim of this study was to determine the cadmium concentration in four muscles and 10 edible offal items of 15 free-range reared Swallow-belly Mangulica pigs from Vojvodina, by flame atomic absorption spectrometry after mineralisation by dry ashing. All individual concentrations in muscles and heart, tongue, spinal cord, back fat and leaf fat were below the limit of detection (LOD?=?0.050?mg/kg). In lungs, spleen and brain, cadmium concentrations ranked from below LOD, 0.055 and 0.058 to 0.057, 0.065 and 0.074?mg/kg, respectively. The concentration of cadmium in liver and kidney ranged from 0.089 to 0.116?mg/kg and from 0.204 to 0.440?mg/kg, respectively. Cadmium concentrations in liver and kidney of free-range reared Swallow-belly Mangulica pigs slaughtered at about 20 months of age were lower than in liver and kidney of commercial pigs from Vojvodina, slaughtered at about 6 months of age.     

Effects of heat,processing time and pH on the microflora,aflatoxin content and storability of “wara”, a soft,white cheese

Employing crude coagulants from sodom apple Calotropis procera, processing conditions of 65–85°C for 40–65 min and reduced pH, reductions in microbial population were found in a locally-produced soft, white cheese “wara”. The finished product “wara” did not keep well under ambient conditions (RH 75 ± 5%, temp. 26 ± 2°C). From some selected critical control points along the line of processing, Bacillus spp., coliforms, staphylococci and moulds Aspergillus and Mucor spp. were isolated. Aflatoxin B₁ (AFB₁) and aflatoxin M₁ (AFM₁) levels of samples examined ranged from 4.8–5.3 μg/kg and 6.4–7.5 μg/kg, respectively. During production, protein and fat contents of the soft, white cheese showed three- to six-fold and three- to four-fold increases, respectively.     

Effect of different production typologies on chemical,physical and sensory characteristics of Italian commercial pork

BACKGROUND: Slaughter weight could influence some chemical, physical and sensory characteristics of pork production. The aim was to compare loin quality from pigs slaughtered at 120 kg or at 160 kg live weight, representing two different Italian lines of commercial production. RESULTS: Physical and chemical traits were affected by slaughter weight, but lower values of moisture (P < 0.01) and higher fat content (P < 0.05) were found in heavy pork loin; furthermore, increased slaughter weight resulted in redder, yellower and more intense colour (P < 0.05). Slaughter weight did not influence the purchase intent or consumer preference, except for fresh meat colour (P < 0.05) preferred in light pigs. A selected and trained panel carried out a difference‐from‐control test, showing that heavy pig loin was redder, more marbled, moister, sweeter, saltier, and had a more metallic flavour and lower tenderness than the light one (P < 0.05). The colour difference of raw meat is the only parameter detected by the consumers. CONCLUSION: Different production typologies affected chemical and physical characteristics of loin. Moreover sensory evaluation showed substantial differences between the loin samples. However, the purchase intent and consumer preference were not influenced by these two production typologies. Copyright © 2008 Society of Chemical Industry