腐乳和豆豉功能性研究进展

发酵豆制品通常被人们当作调味品来食用,但很少有人关注其功能性。本文以腐乳和豆豉为例综述了传统发酵豆制品的降血压、降糖、抗老年痴呆、抗氧化等生理活性功能,并展望了传统发酵豆制品的研究方向。     

传统发酵豆制品生产过程中的安全隐患及改进措施

我国传统的发酵豆制品是以富含植物蛋白的大豆、豆粕等为主要原料,通过发酵微生物酶的作用,发酵水解生成多种氨基酸、各种糖及多种小分子化合物,在经过复杂的生物化学变化形成的各种发酵制品,包括腐乳、豆豉、豆酱、酱油等。传统发酵豆制品具有独特的风味、丰富的营养和保健功能深受大众喜爱。然而,传统发酵豆制品特殊的生产方式使在其原料加工、发酵生产、运输、贮藏过程中存在安全隐患,影响产品质量的稳定性和食用的安全性,因此发酵豆制品的食品安全性成为了目前研究的热点问题之一。文章从传统发酵豆制品的主要种类、产品风味及生产工艺特点,生产原料的安全性问题,发酵微生物的安全性问题,发酵代谢产物的安全性问题等方面对传统发酵豆的生产过程及其产物的安全控制因素的现状和不足进行了分析,并指出了发酵豆制品生产安全控制的改进措施,旨在为相关企业生产管理提供参考。     

发酵豆制品酿造过程中组分和营养功能因子的变化及调控

发酵豆制品是发酵食品中的一大类,在亚洲国家人民饮食中占重要地位,并逐渐受到西方国家青睐。近年来,发酵豆制品酿造过程中产生的功能因子不断被报道,其抗氧化、降血压、降血糖、溶血栓、抗突变等功能性不断被揭示,引起世界广泛关注。发酵豆制品组分变化的调控对增强营养和富集功能因子意义重大,有利于进一步提升其食用价值,促进人类健康。本文综述发酵豆制品生产过程中与营养和功能相关的部分组分的变化及调控,并对该领域的科学问题进行展望。     

发酵豆制品中生物胺的产生及控制研究进展

发酵豆制品主要包括腐乳、豆豉、酱油和豆酱等,豆制品在发酵过程中容易在微生物的作用下产生多种潜在有毒代谢物,其中生物胺（biogenic amines,BAs）是影响发酵豆制品质量安全的重要风险因子之一。过量食用含BAs的食物会引起中毒,但目前国内没有发酵豆制品统一的BAs限量标准。该文对发酵豆制品中BAs的产生机理、影响因素以及控制方法进行综述,旨在通过优化发酵豆制品的生产工艺控制BAs的形成,提高发酵豆制品的质量,推动我国发酵豆制品健康和稳定发展。     

发酵技术对食用种子及其制品改性的研究进展

发酵技术广泛应用于食品生产。食用种子是除乳制品之外良好的发酵载体,发酵可以改变食用种子的营养活性成分、代谢产生新的活性物质且能够降低抗营养因子,可赋予食用种子及其制品更好的加工性质或者表现出降血糖、降血压、减脂、抑癌等生物活性价值,鉴于发酵可赋予可食用种子及其制品更优良的品质,该文综述发酵改性食用种子及其制品的相关应用研究,以期为利用发酵技术改性食用种子及其制品的研究开发提供参考。     

发酵豆制品抗氧化作用的研究进展

大豆发酵食品是我国的一种传统食品,含有丰富的生理活性物质。文章综述了国内外发酵豆制品包括豆豉、腐乳、酱油的抗氧化能力,并对发酵豆制品中的抗氧化成分做出分类总结。     

传统豆制品腐败菌污染及抑制研究进展

传统豆制品营养丰富,含水量大,但容易腐败变质,尤其是鲜食豆制品保质期短、运输储存均需低温冷藏。这严重影响了传统豆制品的产品品质与消费者的食用安全,限制了生产加工企业的产量及其产业化发展规模。确定传统豆制品腐败菌的来源和种类,分析不同腐败菌与豆制品品质变化的相关性,并采用安全有效的方法对其进行抑制,有效延长保质期,日益成为研究热点。从制作传统豆制品的原料大豆自身的种植土壤、种皮微生物与内源微生物,原料预处理、加热残留、加工辅料带入的安全隐患、设备清洗不彻底等生产加工过程的影响,以及贮藏环境影响等方面阐述了引起传统豆制品腐败变质的原因与途径。在原料存储和生产加工中,要进行高标准和严格的食品安全管理；总结了引起传统豆制品腐败的细菌和真菌等主要微生物的来源、腐败现象、污染的豆制品。传统豆制品在贮藏过程中,针对腐败菌群体系呈现出不同优势菌群的动态菌相变化,应用传统方法结合现代技术进行腐败菌的系统分离和鉴定,根据特定腐败菌进行抑制是有效延长保质期的关键；针对传统豆制品腐败菌采用物理杀菌、化学抑菌和生物防腐等抑菌方法及其抑菌机理的阐述。特别是针对不同的传统豆制品品质及腐败菌的特点,采用新型物理杀菌技术结合安全高效、抑菌效果好的生物方法,尤其是对微生物源抑菌剂的应用,为有效延长传统豆制品保质期提供独特的优势,以期为传统豆制品保鲜的新方向提供参考。     

传统发酵大豆制品挥发性成分和微生物多样性的研究进展

传统发酵大豆制品因独特的风味、丰富的营养而深受人们的喜爱,在我国和其他亚洲国家的膳食结构中占重要地位。豆酱、豆豉、腐乳和酱油作为四大传统发酵豆制品,其发酵过程正不断地被科研工作者剖析。该文对四大传统发酵豆制品的挥发性成分和微生物多样性进行了综述,以期为传统发酵大豆行业的发展提供参考。     

中国传统发酵豆制品中微生物的发掘与利用

中国传统发酵豆制品的生产过程中发生了一系列复杂的生化反应，使其制品具有特定的风味、组成和营养。该文简要综述了酱油、豆酱、腐乳和豆豉在发酵过程中微生物的分布及这些微生物在工业生产方面的发掘与利用，通过对菌种的筛选、改良进一步提高产品的营养、风味及功能性。     

发酵豆制品中生物胺含量研究进展

生物胺是一类分子量较低的有机化合物,广泛分布于水果、蔬菜以及发酵食品中。在豆制品发酵过程中微生物代谢产生生物胺,过量摄入生物胺会导致人体中毒。发酵豆制品中生物胺含量较大,但目前国家没有统一的生物胺含量标准。文章对近年来文献报道的针对酱油、豆豉、腐乳3种发酵豆制品的生物胺含量进行了总结。通过对发酵豆制品中生物胺含量进行分析,为确保发酵豆制品的食用安全,进一步控制豆制品中的生物胺含量,制定相应的生物胺含量标准法规提供了理论基础。     

The thermostability, bioactive compounds and antioxidant activity of some vegetables subjected to different durations of boiling: Investigation in vitro

This research was performed in order to compare the water and acetone extracts of raw and boiled for 10, 20, 40 and 60 min Korean lotus roots (KLR) and Polish white onion (PWO) in the contents of their bioactive compounds, antioxidant activity and thermostability.It was found that polyphenols (mg GAE/g), flavanols (μg GAE/g), flavonoids (mg CE/g), anthocyanins (mg CGE/kg) and tannins (mg CE/g) in water extract of raw lotus roots were 14.18 ± 0.7, 8.41 ± 0.5, 1.09 ± 0.06, 21.3 ± 1.2 and 7.29 ± 0.4, and of white onion - 11.11 ± 0.6, 6.78 ± 0.3, 0.71 ± 0.03, 17.00 ± 0.9 and 1.64 ± 0.08, respectively, and significantly higher in KLR (P < 0.05). The antioxidant activity of raw KLR water extract (139.4 ± 6.1, 53.1 ± 3.6 and 89.3 ± 4.6 μmol TE/g for DPPH, CUPRAC and ABTS, respectively) was significantly higher than in white onion (23.84 ± 1.8, 31.9 ± 2.1 and 38.14 ± 2.6 for DPPH, CUPRAC and ABTS, respectively, P < 0.05).The thermostability of the water KLR extract’s of polyphenols, flavanols, flavonoids, anthocyanins and tannins was high and even after 60 min of boiling remains as 40.0, 42.3, 50.5, 41.4 and 41.0%, respectively. After 60 min of boiling the most thermostable compounds were flavonoids - remaining at 50.5% in water extract of KLR. Also after 60 min of boiling the thermostability of the antioxidant activity of water extracts of KLR remained significantly high: 40.6, 42.3, 46.3 and 43.6%, according to DPPH, FRAP, ABTS and CUPRAC assays, respectively.Similar relationship was obtained with acetone extracts, but the value was lower than with the water ones. In conclusion, the contents of some bioactive compounds, the antioxidant activity and the thermostability in water and acetone extracts of KLR are significantly higher than the same indices in PWO. FTIR and fluorimetry can be used as additional markers for the characterization of bioactive compounds in vegetables.     

Nutritive value of masau (Ziziphus mauritiana) fruits from Zambezi Valley in Zimbabwe

Ziziphus mauritiana (masau) fruits are consumed by many people in Zimbabwe. The fruits contribute significantly to people’s diet when they are in season. The objective of this study was to determine the nutritional content of the fruits and, hence, quantify their contribution to the diet. Samples of masau were collected in two seasons (August 2006 and August 2007). Both macronutrients and micronutrients were determined using standard AOAC methods of analysis. Dry matter content ranged from 21.1 ± 0.2 to 24.1 ± 0.3 g 100 g⁻¹ of edible portion of the sweet and sour fruits, and 84.8 ± 0.2 to 87.2 ± 0.2 g 100 g⁻¹ for the dried fruit. Crude protein per 100 g edible portion of dry weight ranged between 7.9 ± 0.0 and 8.7 ± 0.0 g, crude fat from 0.8 ± 0.0 to 1.5 ± 0.0 g, crude fibre from 4.9 ± 0.0 to 7.3 ± 0.0 g, ash between 3.0 ± 0.0 and 4.3 ± 0.0 g and carbohydrate between 79.5 ± 0.0 and 83.2 ± 0.0 g. The fruits were rich in vitamin C (15.0 ± 0.0–43.8 ± 0.02 mg 100 g⁻¹) and the energy values ranged between 1516.0 ± 1.73 and 1575.0 ± 2.3 kJ 100 g⁻¹. Furthermore, the fruits contained (mg 100 g⁻¹ of dry weight) potassium from 1865.0 ± 1.3 to 2441.0 ± 1.1, calcium from 160.0 ± 0.3 to 254.0 ± 0.1, sodium between 185.0 ± 0.1 and 223.0 ± 0.2, magnesium between 83.0 ± 0.0 and 150.0 ± 0.13 and phosphorous from 87.0 ± 0.1 to 148.0 ± 0.5. Manganese and copper contents ranged between 0.7 ± 0.03 and 1.6 ± 0.03, while iron and zinc ranged between 2.1 ± 0.43 and 4.3 ± 0.1, and 0.6 ± 0.0–0.9 ± 0.0 mg 100 g⁻¹ of dry weight, respectively. The masau fruit is therefore a good potential source of carbohydrates, proteins and micronutrients, such as calcium, potassium, sodium, phosphorous, copper, iron, Vitamin C and zinc.     

Evaluation of culture media for enumeration of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium animalis in the presence of Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus

The study compared the growth capability of probiotic (Lactobacillus acidophilus La05, Lactobacillus casei Lc01 and Bifidobacterium animalis Bb12) and non-probiotic (Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus) cultures on twenty-one culture media grouped according to selectivity: non-selective agars, selective agars without antibiotics and MRS agars containing different combinations of lithium chloride, cystein, bile salts and antibiotics. Four of these media were selected for quantitative enumeration of L. acidophilus La05, L. casei Lc01, and B. animalis Bb12. The best culture media and incubation conditions for enumeration of the probiotic cultures were: B. animalis: MRS agar with dicloxacillin, 37 °C or 42 °C, anaerobiosis; L. acidophilus: MRS agar with bile salts, 37 °C or 42 °C, aerobiosis; L. casei: MRS agar with lithium chloride and sodium propionate, 37 °C or 42 °C, aerobiosis or anaerobiosis. Plating on MRS with glucose replaced by maltose, 37 °C or 42 °C, anaerobiosis, will distinguish probiotic from non-probiotic cultures. For enumeration of each probiotic in a mixed culture, the following media and incubation conditions were recommended: B. animalis: 4ABC-MRS, 42 °C, anaerobiosis, L. acidophilus: LC medium, 42 °C, aerobiosis or anaerobiosis and L. casei: LP-MRS, 42 °C, aerobiosis or anaerobiosis. In all experiments, differences in counts using pour plating or surface plating were not significant (P ≤ 0.05).     

Quality assessment of wild European eel (Anguilla anguilla) stored in ice

The quality assessment of wild European eel (Anguilla anguilla) stored in ice and in boxes without ice (3 ± 1 °C) was investigated by the sensory analysis, levels of nucleotide breakdown products and biogenic amines for up to 19 days. Sensory analysis was assessed using the Tasmanian Food Research Unit Scheme. K and related values (K_i, G, P, H and F_r) were used as freshness indicators. Linear regressions (r²) obtained from K, K_i, G, P, H and F_r were 0.95, 0.96, 0.83, 0.96, 0.99 and 0.96, respectively, for eel stored in ice whereas, for eel kept in boxes without ice, the values were 0.86, 0.86, 0.96, 0.91, 0.98 and 0.86, respectively. When eel stored in ice and in boxes without ice were considered at the limit of acceptability by assessors at ∼12–14 days and ∼5–7 days, respectively, the average K, K_i and P values were ∼70–85%, H values were ∼60% and F_r values were ∼10% for both storage conditions. The level of histamine exceeded the legal limit (5 mg/100 g fish) in eel stored without ice after 6–7 days and, in ice, after 13–14 days of storage, at which time eels were rejected by the sensory panel. The concentrations of biogenic amines were higher in eel stored in boxes without ice than in eel kept in ice. The levels of histamine in the muscle of eel kept in boxes without ice and in ice increased to the maximum levels of 17.9 mg/100 g on day 12 and 12.6 mg/100 g on day 19, respectively.     

Effect of temperature on the development of the yam moth, Dasyses rugosella Stainton (Lepidoptera: Tineidae)

Studies on the effect of temperature on the development of the yam moth, Dasyses rugosella Stainton were carried out in the laboratory at four different temperatures, 20°C, 24°C, 29°C and 33°C. The mean fecundity per female at 20°C, 24°C, 29°C and 33°C was 37.6±1.9, 84.2±2.7, 112.3±3.9 and 109.3±3.9 eggs, respectively. Oviposition period ranged from 4.7 days at 20°C to 2.9 days at 33°C. Hatchability of eggs was highest at 29°C with 70.0% and lowest at 20°C with 15.0%. The developmental time decreased with increase in temperature. The mean developmental time at 20°C, 24°C, 29°C and 33°C was 13.8±0.3, 7.8±0.2, 5.1±0.2 and 3.9±0.2 days for the egg, 90.0±0.7, 50.1±0.7, 36.1±0.8 and 23.6±0.8 days for the larval stages, 22.3±2.6, 12.2±0.2, 10.1±0.1, and 7.8±0.2 days for the pupa and 126.1±0.8, 70.1±0.8, 51.3±0.9, and 35.1±0.8 days for the period from egg hatching to adult emergence, respectively. Since fecundity, oviposition and development of the moth were impaired at 20°C, storage of yam tubers at low temperatures (well below 20°C but not lower than 12°C to avoid chilling injury) will significantly retard the development of D. rugosella and help in its control. Unmated individuals lived longer than their mated counterparts. Adult females were always larger than the males. The wing span of the female ranges from 16.9-18.5 and in males from 13.0-15.0 mm. The body length for males ranged from 5.0-6.5 and was 6.5-9.0 mm for females.     

Effects of light,temperature and water activity on the kinetics of lipoxidation in almond-based products

Lipoxidation in almond-derived products was investigated using the chemiluminescence (CL) and thiobarbituric acid-reactive substances (TBARS) methods to detect the first and later reaction products, respectively. The effects of light during storage at 5 °C, 22 °C and 40 °C were studied, as well as the effects of combined heat/water activity treatments in the 60–120 °C and 0.38–0.72 range. During storage, light was found to enhance the CL and TBARS values, and specific responses were observed in almond paste and the final Calisson product. During the heating of almond paste, as the initial water activity (a_w) increased, the CL rate constants increased during heating to 60 °C and 80 °C, but interestingly, these values decreased during further heating to 120 °C, whereas the maximum TBARS rate constants occurred at a_w 0.57 at all the heating temperatures tested. The activation energies, based on the CL and TBARS values, decreased specifically when the a_w increased from 0.38 to 0.72, giving overall values ranging from110 kJ mol⁻¹ to 60 kJ mol⁻¹. Likewise, in the same water activity range, the temperature-dependent rate constant enhancing factor (Q₁₀) decreased from 3.3 to 1.6.     

Protective effects of a synthetic soybean isoflavone against oxidative damage in chick skeletal muscle cells

The antioxidant and protective properties of a synthetic soybean isoflavone (SI) were investigated using chick skeletal (leg) muscle cells (SMC) isolated from 20-day-old Linnan yellow broiler chick embryo. Skeletal muscle cells were cultured in Dulbecco’s modified Eagle’s medium treated with 0, 12.5, 25, 50, 75 and 100 μM SI, respectively, under 80 μM H₂O₂/FeSO₄ conditions. After 24 h of incubation, SI reduced the loss of SMC under oxidative stress by H₂O₂/FeSO₄. The addition of SI significantly promoted SMC proliferation (P < 0.01). Upon treatment with 25, 50, 75 and 100 μM SI, the activity of total superoxide dismutase in the supernatant of the media was enhanced by 17.0%, 13.0%, 13.3% and 11.9%, respectively (P < 0.05). Compared to the control, the activity of glutathione peroxidase was significantly increased only at 25 μM concentration of SI (P < 0.05), and the increment was 90.7%. The activity of catalase was increased by 49.2% and 49.1%, respectively, at 75 and 100 μM SI (P < 0.01). The concentration of creatine kinase in the media was decreased by 61.6% and 60.6%, respectively, at 75 and 100 μM SI (P < 0.01). The addition of SI did not affect the activity of lactate dehydrogenase in the media. In conclusion, the SI protected skeletal muscle cells from oxidative damage, attributed to its antioxidant activity.     

Crude glycerine inclusion in Limousin bull diets: Animal performance,carcass characteristics and meat quality

Three hundred and six Limousin young bulls (7 ± 1 months of age, initial body weight 273 ± 43 kg) were used to evaluate the effect of crude glycerine supplementation on animal performance, carcass characteristics and meat quality. Animals were assigned to three different diets: Control (0% of crude glycerine), G2 and G4 (2 and 4% of crude glycerine, respectively). The diets were administrated ad libitum for 240 days (final body weight 644 ± 24 kg). Average daily weight gain, average daily feed intake, the gain:feed ratio, ultrasound measures in vivo, carcass characteristics, pH, water holding capacity, drip losses, and cooking losses were not affected (P > 0.05) by diets. Diet decreased C16:0 (P < 0.01) and C16:1 (P < 0.05) contents in meat. The G4 meat showed lower C12:0, C14:0, C17:0, C18:0, C18:1, C18:2, C18:3, c9,t11-c18:2, C20:0 and C20:4 levels (P < 0.05) than control. Glycerine increased desirable fatty acid percentages (P < 0.05) in intramuscular fat.     

Mineral content of tropical fruits and unconventional foods of the Andes and the rain forest of Colombia

A total of 68 species of starchy foods, tropical fruits, leaves and tubers (101 samples), were collected on the foothills of the Colombian Andes and in the rain forests of the Colombian Pacific coast. Their edible portion was analyzed for mineral content (Ca, P, Mg, K, Na, Cl, S, Mn, Zn, Fe, Cu, Se, Co, Ni). The foods were generally high in K (36–1.782 mg K/100 g edible portion) and low in sodium (<45 mg Na/100 g edible portion). The tree foliages had the highest contents in most of the elements, especially in calcium (280–1242 mg Ca/100 g edible portion, i.e., up to 62 g Ca/kg dry matter) and iron (0.7–8.4 mg Fe/100 g edible portion). Correlations (P < 0.001) were observed between total ash and many elements, especially Ca and Mg (r =  0.77 and 0.73, respectively). High correlations were also obtained between Ca and Mg (r = 0.93).     

Effect of multiple factors on accumulation of nucleosides and bases in Cordyceps militaris

In order to improve the accumulation of valuable metabolites (3′-deoxyadenosine, adenosine, guanosine, cytidine, uridine, adenine and uracil) in Cordyceps militaris, multiple factors such as carbon sources, nitrogen sources, metal ions and fermentation duration were investigated in liquid shake flasks. Using both potato broth and glucose as carbon sources were found to facilitate the production of nucleosides and bases most, and 2% of glucose was the most suitable initial level. Mixture of 0.3% yeast extract with 0.3% peptone was the best selection of nitrogen sources and supplementing with 0.1 mmol/L Mn²⁺ achieved the maximum biomass and biosynthesis of nucleosides and bases among all investigated metal ions. The most suitable harvest time for C. militaris was found to be the 6th day, because the production of 3′-deoxyadenosine, adenosine and uridine began to speed up from the later exponential growth phase until the 6th day. Finally, under optimal culture conditions, the contents of 3′-deoxyadenosine, adenosine, guanosine, cytidine, uridine, adenine and uracil were increased to 0.212 ± 0.014 mg/g, 5.05 ± 0.31 mg/g, 4.03 ± 0.30 mg/g, 0.556 ± 0.029 mg/g, 6.39 ± 0.33 mg/g, 0.208 ± 0.016 mg/g and 0.437 ± 0.027 mg/g, respectively.