中国石榴产销情况

本文介绍了国内外石榴的种植情况,分析了我国石榴的产销情况及存在的问题,在此基础上提出了石榴产业发展的建议和策略。     

石榴气调保鲜效果研究

院本文研究了气调保鲜技术对贮藏期间石榴品质的影响。结果发现,在2益低温条件下,4%O2协同5%CO2,贮藏140d时,石榴的呼吸强度为22.01mgCO2/（kg·h）,褐变指数为0.16,可溶性固形物及总酸含量分别为14.7%与0.41%,可以较好地维持石榴的品质与口感。该处理石榴MDA含量累积最少,对PPO活性及果实腐烂抑制作用最强。     

石榴贮期果皮褐变机理的研究

【目的】研究石榴贮期果皮褐变机理，探讨防褐变技术。【方法】以采后陕西临潼净皮甜石榴为试材，研究了贮藏温度、气体成分和pH对果皮褐变的作用，测定了引起果皮褐变的主要物质单宁的变化规律，分析了抗坏血酸氧化酶（AAO）、多酚氧化酶（PPO）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性与果皮褐变的关系。【结果】单宁是石榴果皮褐变的底物；AAO、PPO、POD活性与果皮褐变指数呈正相关性，CAT活性与果皮褐变指数呈负相关性。石榴在pH 4.0、（5.0±0.5）℃、5.0% CO2+8.0%O2+87.0%N2的气体成分条件下贮藏，每隔5 d在（15±0.5）℃下间歇升温处理24 h，贮藏120 d褐变指数仅为0.15。【结论】石榴贮期酶促单宁变性是果皮褐变的主要原因，在适宜的pH、贮藏温度和气体成分条件下间歇升温贮藏，防褐变效果理想。     

Investigation of Natural Extracts and Sodium Bisulfite Impact on Thermal Signals and Physicochemical Compositions of Litopenaeus vannamei during Chilled Storage

This research work evaluates the impact of 1.2% pomegranate peel extract (Pp) (Punica granatum), 0.1% grapefruit seed (Gfs) (Citrus paradisi) extract, and synthetic preservative 1.25% sodium bisulfite on shelf life extension of Litopenaeus vannamei stored at 4 and 15°C. The application of isothermal titration calorimetry (ITC) for comparison of the extracts and chemical preservative on shrimp quality retention based on the overall heat production by microbial and enzymatic degradation was addressed. The occurrence of probable bioactive responsible for antimicrobial and antioxidant activity components in the extracts was examined through gas chromatography-mass spectrometry (GCMS). At 4°C, Pp-treated shrimps resulted in 6.73 logCFU/g, 6.93 logCFU/g, 5.31 mgN/100 g, and 0.58 mgMDA/kg for aerobic plate count, psychrotrophic bacterial count, trimethylamine, and thiobarbituric-acid reactive substance, respectively, on the 15th day. At 15°C, Pp-coated shrimps retained quality until day 4. Isothermal calorimetric analysis resulted in a rapid and sharp peak for fresh samples, whereas there was broad and delayed peak for shrimp treated with Pp and sodium bisulfite. These observations prove that Pp counterpart the chemical preservative and outperform Gfs on shrimp quality retention. Results also indicate that isothermal calorimetry can be a useful technique for shelf life predictions and comparative evaluation of extract impact on shrimp quality retention.     

石榴软籽新品种‘豫农早艳’的选育

‘豫农早艳’石榴是由‘突尼斯软籽’石榴芽变选育出的早中熟软籽石榴新品种。果实近球形,果形指数0.84;平均单果质量300 g,最大单果质量680 g;果皮底色黄绿,着玫红色晕,着色面积超过70%;萼筒较短,萼片开张或半开张;籽粒粉红色。‘豫农早艳’石榴百粒重37.0 g;出籽率62.3%以上,出汁率84.6%;可溶性固形物含量(w,后同)17.1%,pH 3.4,维生素C含量12.6 mg·100 g^-1。风味酸甜可口,籽粒易剥离;籽粒硬度3.26 kg·cm~(-2),核软可食。果实生育期120 d左右,在郑州荥阳(东经113.35,北纬34.79)9月中下旬成熟,比‘突尼斯软籽’石榴早熟约10 d。该品种植株长势中庸,树姿半开张;耐旱、耐瘠薄,较抗冻,适应性较强。货架期20 d左右,5℃冷库贮藏60 d左右。适合黄河以南石榴适生区栽培,第2年开花结果,丰产,稳产。