Determination of Chlorophylls in Kiwi Fruit and Their Changes during Ripening

Chlorophylls were separated into a and b compounds by thin-layer chromatography and determined using a dual-wavelength chromato-scanner. A linear relationship existed in the range 0.1-1.0 μg for chlorophyll a (chla) and 0.1-0.7 μg for chlorophyll b (chlb). The recoveries of chia and chlb when added to kiwi fruit were 79.4% and 99.5%, respectively. Total chla+ chlb contents of four cultivars of kiwi fruit (Abbott, Bruno, Hayward and Monty) were 2000-3000 μg/ 100g at the beginning of growth, but decreased to about 1000 μg after four months. This decrease was mainly due to a decrease in chla. Total chlorophyll content decreased gradually during post-harvest ripening.     

辣椒类胡萝卜素在加工与贮存中的变化

本文综述了辣椒加工与贮存条件对其类胡萝卜素变化的影响。加工与贮存过程中，导致色素损失的主要因素包括品种特性，光，热，水分含量等。不同类胡萝卜素对条件因素的敏感性也是不一样的。     

不同部位雪茄烟叶晾制过程中多酚、色素及相关酶活性的变化

为明确晾制过程中雪茄烟叶多酚类物质和质体色素的降解规律以及相关酶活性的动态变化,以德雪1号为试验材料,研究了不同部位烟叶晾制期间多酚类物质、质体色素及相关酶活性的变化规律,并进行了相关分析。结果表明,不同部位雪茄烟叶中多酚类物质含量主要表现为中部叶 > 下部叶 > 上部叶,其中各部位绿原酸含量均呈下降趋势,而芸香苷和莨菪亭含量均呈现单峰曲线。各部位质体色素含量随着晾制过程的推进而逐渐降低,整体表现为上部叶 > 中部叶 > 下部叶。各部位烟叶中脂氧合酶、苯丙氨酸解氨酶、多酚氧化酶、过氧化物酶等酶活性均呈先增后降趋势。相关分析表明,晾制期间各部位多酚氧化酶活性与多酚、色素含量呈正相关,且与绿原酸和β-胡萝卜素达到显著水平;苯丙氨酸解氨酶活性与多酚、色素含量呈负相关,且与绿原酸达到显著水平。过氧化物酶与脂氧合酶、苯丙氨酸解氨酶、多酚氧化酶均呈显著正相关,因此在晾制过程中合理调控各类酶活性,可以控制多酚类物质及质体色素含量,有利于提高雪茄烟叶调制特性。     

Viscoelastic Property Changes in Cheddar Cheese During Ripening

The rheological properties of pasteurized and raw milk Cheddar cheese were studied using oscillatory dynamic measurements, and a specially designed rheometer fixture that prevented specimen slippage. Dynamic measurements within the linear viscoelastic range were made throughout ripening. Within-cheese changes, as related to ripening time, as well as between-cheese-type differences in G’ and G” were observed. Differences in rheological characteristics were attributed to proteolytic activities in Cheddar cheese during ripening. Specific peptide profiles associated with proteolysis during ripening may affect cheese rheological properties.     

Changes in Chemical Constituents of Kiwifruit During Post-Harvest Ripening

Kiwifruit (Actinidia chinensis Planch, Hayward cultivar) were ripened at 20°C under a stream of water-vapor saturated air containing 5 ppm ethylene gas. A remarkable rapid softening in the texture and rising of the soluble solids were observed in 24 hr. The total acidity, starch and amylose content decreased during ripening. Both fructose and glucose increased from 2.7% to 5.0% after 5 days of ripening. Sucrose content increased from 0.45% to 2.22% on the second day, then decreased to 1.19% after 5 days. No significant change in chlorophyll and total solids were observed throughout the experiment. There were stepwise decreases in the L and b_L values during ripening. The ascorbic acid content decreased from 210 to 190 mg per 100g fresh fruit after 5 days of ripening.     

Organic Acid Changes During Ripening of Processing Peaches

Organic acids and their changes during peach (Prunus persica L. Batsch) fruit ripening were quantified by HPLC for clingstone culti-vars,‘Babygold 5’and‘Babygold 7′, and a freestone cultivar,‘Cresthaven’. At full maturity,‘Babygold 5’and‘Babygold 7’had about 60% malic, 20% citric and 19% quinic acid; whereas‘Cresthaven’had similar amounts of all three organic acids (37, 3.5 and 28%, respectively). During fruit ripening,‘Babygold 5’and‘Babygold 7’increased in malic acid and decreased in citric and quinic acids, whereas,‘Cresthaven’showed little change in these organic acids.     

辣椒果实成熟过程中辣椒素的降减

试验表明,随着辣椒果实成熟,辣椒果肉及胎座中辣椒素含量的变化均是先升达到一定高峰后又略有下降;过氧化物酶活性的变化品种间有所差异,农大２１号的过氧化物酶活性至绿熟期升至高峰,之后下降,红熟期又略有回升;农大２２号在红熟期达到最高值。在果实成熟期,辣椒素含理与过氧化物酶活性的变化呈负相关变化,胎座中的辣椒素含量远高于果肉而过氧化物酶活性远低于果肉。说明辣椒果实发育过程中,过氧化物酶 辣椒素的,降解一     

冷冻豆腐熟化期间的质构变化

本文主要研究了豆腐在一般冷冻和快速冷冻情况下熟化期内的质构变化情况,并得出快速冷冻豆腐的弹性要比一般冷冻的好。     

辣椒提取液的抑菌活性分析

用辣椒的乙醇提取液对12种常见的模式致病菌株进行体外抑菌试验,结果表明,该提取液对细菌、霉菌和酵母菌均表现出一定的抑菌作用,其抑菌效果随浓度的增大而增强。其中提取液对葡萄牙假丝酵母的抑菌效果最明显,对根癌土壤杆菌抑菌效果最差。此外,同一浓度提取物对不同菌株的抑菌作用不同,其抑菌效力对菌种具有选择性,并且其抑制真菌的效果明显强于细菌。HPLC分析表明,辣椒提取液中的主要化学成分为辣椒素,其含量为0.132mg/mL。     

Compositional Changes in Mango Fruit During Ripening at Different Storage Temperatures

Chemical changes in Haden, Irwin, Kent, and Keitt mangos stored at 16-28°C and 85-90% RH were followed to determine the optimum storage and ripening conditions. Weight loss was slightly higher at 25° and 28°C than at 16-22°C. Breakdown in acidity during ripening was slower at 16°C. Vitamin C showed two basic trends; a general decrease as in Haden, Irwin, and Keitt or a steady increase as in Kent. Total and β-carotenoids were significantly higher at 22-28°C than at 16-20°C. No significant differences were observed with respect to carbohydrate and soluble solids content. However, sucrose increased spectacularly at all temperatures contributing most to the increase in sweetness. The pattern of chemical changes were strikingly similar in all the varieties. Temperatures of 20-22°C and 85-90% RH are recommended for storage and ripening of mangos to obtain sufficiently acceptable quality attributes.     

Changes in volatile compounds of a native Chinese chilli pepper (Capsicum frutescens var) during ripening

The objective of this study was to identify the volatile components of a native Chinese chilli pepper (Capsicum frutescens var) at different ripening stages. The peppers at green, breaking and red colour stages were first investigated by simultaneous distillation extraction combined with gas chromatography and mass spectrometry. Principal component analysis was used to visualise the grouping tendencies of the studied stages of pepper. Eighty‐five volatile organic components were identified and quantified in this study. Forty compounds were found at the green stage, fifty‐three at the breaking stage and sixty‐five at the red colour stage. The flavour activity compounds were discovered in Chinese pepper. Qualitative and quantitative discrepancies were observed in different ripening stages. The amount of alkenes and aldehydes increased from 2.762% and 0.120% in green stage to 11.137% and 14.485% in colours’ stage. The content of Alcohols decreased from 30.169% to 23.698%. Only, the aromatic compound disappears during maturity. Ketones enhanced from 0.983% to 2.693%. Esters were always reducing.     

Antibacterial Activity of Two Bell Pepper Extracts: Capsicum annuum L. and Capsicum frutescens

This study was conducted to determine extracts of fruit used as food ingredients and in traditional medicine for antibacterial activities. The effect of Capsicum annuum and Capsicum frutescens methanol and aqueous extracts on selected bacteria (Staphylococcus aureus, Salmonella typhimurium, Vibrio cholerae, Pseudomonas aeruginosa, Escherichia coli, and Shigella dysenteriae) were investigated. Both extracts were found to be effective against Vibrio cholerae, Staphylococcus aureus, and Salmonella typhimurium, while methanol extracts showed the greatest effect. The extract from Capsicum annuum showed a higher antibacterial activity than the one from Capsicum frutescens. The minimal inhibitory concentrations of methanol and aqueous extracts were 0.20 mg mL^?1 and 0.25 mg mL^?1, respectively. Minimal bactericidal concentrations values of both extracts ranged from 1 to 2.5 mg mL^?1. Phytochemical assay revealed the presence of alkaloids, flavonoids, polyphenols, and sterols. Thus, Capsicum fruits may serve as a source of natural bactericidal agents to be used in food and medicinal systems.     

贵州辣椒中的氟含量控制研究

贵州辣椒在干制过程中,由于多采用传统的煤火明火干制,使得含有大量氟的煤烟与辣椒直接接触而导致辣椒中也带入大量的氟,文章针对辣椒中氟化物的来源及辣椒中氟化物溶于水的性质,通过采取不同的干制方法和后续清洗等加工处理,对贵州辣椒中的氟含量进行控制研究,对有效降低辣椒中氟含量取得较好效果。     

Changes in Numbers and Kinds of Lactic Acid Bacteria During Ripening of Kefalotyri Cheese

Changes in lactic acid bacteria in ripening Kefalotyri cheese were studied. Throughout ripening lactobacilli and enterococci counts were high (lactobacilli 10⁶-10⁹/g, enterococci 10⁴-10⁷/g). Leuconostocs, lactic streptococci and betabacteria disappeared early in ripening. Leuconostoc lactis and Streptococcus thermophilus prevailed intitially (23% and 13%, respectively). Enterococcus faecium, Lactobacillus casei and L. plantarum became predominant with ripening. After 4 months ripening, E. faecium were dominant (35.5%) followed by L. plantarum (18.4%) and L. casei subsp. casei (15.8%). Results suggested that a starter consisting of both lactic acid bacteria that disappeared early and lactic acid bacteria that survived throughout ripening should be preferable for the production of Kefalotyri cheese.     

Physicochemical Changes in Seven Tomato (Lycopersicon esculentum) Cultivars During Ripening

Seven tomato cultivars were studied for compositional changes during ripening at green, breaker, turner, and ripe stages. Result indicated changes in total soluble solids (4.15 to 6.62 g/100 g), acidity (0.36 to 0.54 g/100 g), reducing sugars (0.76 to 4.04 g/100 g), total sugars (1.67 to 5.52 g/100 g), lycopene in skin (0.07 to 14.28 mg/100 g), and in pulp (0.04 to 6.73 mg/100 g) during ripening from green to red ripe stage. Cultivar UC-828 was found superior with respect to total soluble solids (6.62 g/100 g), reducing sugars (4.04 g/100 g), and total sugars (5.52 g/100 g) where as cultivar 8–2–1–2–5 was found superior with respect to lycopene in skin (14.28 mg/100 g) and in pulp (6.73 mg/100 g). Hunter color values showed a change from negative value of ‘a’ (greenness) to positive values (redness) where as ‘b’ decreased. The (b/a) and tan^?1 (b/a) showed a similar pattern of first increased and then decreased. The puncture resistance was decreased from 10.5 to 2.3 N indicating softening during ripening. Correlation studies showed that lycopene content best correlated with Hunter ‘a’ values during ripening (R² = 0.84 to 0.93). Intercultivar variation in physicochemical parameters at all stages of ripening revealed that Castle Rock was the best cultivar.     

贵州辣椒的降氟技术研究

为降低贵州辣椒中的氟化物含量,采取不同的干制方法和浸泡、蒸煮、清洗等加工处理,对贵州辣椒中的氟含量进行控制。结果表明,通过采用清洗、浸泡处理,以及提高浸泡温度或进行蒸煮处理,均可明显降低由于煤烟所导致的氟化物含量。工艺为:采用常温浸泡30 min、或高温蒸煮10 min后清洗2次,即可获得降低贵州辣椒中氟含量的较好效果。     

威代尔葡萄成熟及后熟过程中游离态萜烯类香气的变化

目的:以酿制冰葡萄酒的主要品种——威代尔葡萄为试材,研究威代尔葡萄果实中重要的香气成分——萜烯类化合物在成熟、后熟过程中含量的变化,为掌握、调控冰葡萄酒中的香气形成机制提供基础。方法:采用HS-SPME-GC/MS对成熟及后熟阶段威代尔葡萄果实中游离态萜烯类香气成分进行提取、定性和定量分析。结果:共检测到8种萜烯类香气成分,定量分析结果表明,在花后120～150 d之间,游离态萜烯类香气成分的含量变化显著,大多数萜烯类香气成分在达到最高含量后,伴随气温的下降而急剧下降。结论:采用HS-SPME-GC/MS有效实现了威代尔葡萄样品中游离态萜烯类化合物的提取与检测,8种游离态萜烯类香气成分在果实成熟期得到最大程度的积累,而后熟期其含量普遍下降,这与产地气温的降低有一定的关联。     

Characterization of Textural Properties and Changes of Myofibrillar and Sarcoplasmic Proteins in Salame Felino During Ripening

Textural properties and changes of myofibrillar and sarcoplasmic proteins of salame Felino, a typical Italian dry-cured fermented sausage, were studied during ripening. Hardness, chewiness, and gumminess increased over the ripening period. Adhesiveness showed a gradual but significant decrease after 14 days and further at 28 days of ripening. A remarkable increase of the proteolysis index and a significant decrease of myofibrillar and sarcoplasmic protein solubility were observed. Hardness showed a significant negative correlation with myofibrillar protein solubility. Sarcoplasmic proteins appeared to be more susceptible to degradation.