EFFECT OF ANTEMORTEM JOURNEY AND LAIRAGE AT ABATTOIR ON RABBIT MEAT QUALITY

A study was conducted to determine the effects of journey duration (1 versus 3 h) and lairage time at abattoir (0 versus 5 h) on rabbit meat quality traits. Rabbits transported for 3 h produced meat with significantly higher pH values ( P <  0.01), darker (lower L* values, P <  0.01) and less yellow ( P <  0.05) color, as well as lower losses during cooking ( P <  0.01), than those transported for 1 h. Moreover, animals laired for 5 h yielded meat with more ( P <  0.05) yellow color, cooking losses ( P <  0.05) and higher shear values ( P <  0.01) than rabbits not laired before slaughtering. The nuclear magnetic resonance analysis revealed that these differences ( P <  0.05) are mainly related to changes occurring in the distribution of myofibrillar (T₂₁) and extra-myofibrillar (T₂₂) water. In conclusion, this study indicated that journey time and lairage at abattoir may play an important role in determining rabbit meat quality traits.

PRACTICAL APPLICATIONS

In many previous studies that considered the effect of journey and lairage on rabbit meat quality, animals were stress-induced by extreme conditions of journey and/or lairage that were unlikely to occur during commercial operations. The aim of this study is to establish whether meat quality characteristics are still influenced when journey and lairage times match current commercial production practices. Because processing-plant efficiency depends on product uniformity, it will be interesting to test the potential variability effect of rabbit preslaughter practices on meat quality properties.     

ORGANIC ACIDS PROFILE IN TOMATO JUICE BY HPLC WITH UV DETECTION

A simple method was developed to determine 10 organic acids simultaneously in tomato products using reverse‐phase high performance liquid chromatography (HPLC) column with the diode array detector set at 210 nm. After centrifugation and filtration, the samples were passed through to an anion exchange resin and the organic acids were released using 0.1 N HCl. The chromatographic separation was achieved with isocratic analysis in a 20‐min run. The method was reliable and sensitive. The coefficient of determination of the standard calibration curve is 0.9925 ≤ r² ≤ 0.9999 and the limit of detection ranged from 0.08 to 6.00 mg/kg for trans‐aconitic acid and acetic acid, respectively. The limit of quantification ranged from 0.19 to 15.18 mg/kg for trans‐aconitic and acetic acid, respectively. To establish the efficiency of the anion resin the procedure was applied to a standard solution of a mixture of organic acids. The organic acids recovery ranged from 87.0% ± 1.9 for citramalic acid to 109.9% ± 5.2 for fumaric acid.     

Postharvest ethylene and 1-MCP treatments both affect phenols, anthocyanins, and aromatic quality of Aleatico grapes and wine

Aleatico grapes (Vitis vinifera L. cv. Aleatico) picked at 20.4–20.6^oBrix were treated with air containing 500 mg/L ethylene for 15 h, or 1 mg/L 1‐MCP (1‐methylcyclopropene) for 15 h, or 1 mg/L 1‐MCP for 15 h + 500 mg/L ethylene for further 15 h, or air (control). All treatments were imposed at 20^oC and 95–100% relative humidity. Samples undergoing treatment were then held in air at 20^oC and 85% relative humidity for 13 days. Ethylene production from ethylene‐treated grapes was very high (25 μL/kg.h) immediately after treatment, and declined progressively until day 6; 1‐MCP‐ethylene‐treated grapes showed lower ethylene production (10 μL/kg.h). This high ethylene production was mainly due to in‐out diffusion of ethylene absorbed during the treatment, but a potential effect of 1‐MCP is postulated, since 1‐MCP‐treated grapes did not show ethylene production for 2 days after treatment, whereas control grapes produced constant amounts (3–4 μL/kg.h) of ethylene. After day 6, no significant difference was observed among samples. No difference in respiration was revealed. Total phenols were increased significantly by ethylene treatment from 520 mg/L up to 710, while total anthocyanins were lost in air‐treated samples (from 175 mg/L to 120) and remained constant in ethylene and 1‐MCP‐treated grapes. HPLC analyses of anthocyanins confirmed this result: air‐treated samples lost anthocyanins rapidly while this loss was delayed in gas‐treated samples. Terpenols, esters, alcohols, and C6 compounds were increased by ethylene treatment. Conversely, 1‐MCP‐treated grapes showed a significant loss of terpenols and esters, although maintaining alcohols, especially hexan‐1‐ol. Berry pathology was also affected, with 1‐MCP and 1‐MCP‐ethylene treated grapes hosting a diffuse attack of grey mould. Wine analyses revealed higher concentrations of phenols and anthocyanins in wine from ethylene‐treated grapes, although aromatic compounds were lost, and thus the aroma profile of those wines was diminished.