Evaluation of phenolic compound composition of Sambucus nigra berries grown in Latvia

A. Avena*, L. Ozola and A. Keke

Latvia University of Life Sciences and Technologies, Faculty of Agriculture and Food Technology, Institute of Food, Lielā iela 2, LV-3001, Jelgava, Latvia
*Correspondence: anita.avena@gmail.com

Abstract:

Phenolic compounds in agricultural raw materials can vary within a species and can be affected by a combination of such factors as growing region, weather conditions and fruit ripeness. Climatic differences between the southern, central and northern parts of Europe can cause differences in the phenolic compounds present in the plant. The research was aimed to investigate the phenolic compounds of berries of Sambucus nigra varieties grown for commercial production in Latvia. During the study four elderberry varieties were analysed – ‘Haidegg 17’, ‘Korsör’, ‘Haschberg’ and ‘Emma’. All samples were analysed for total phenolic compound content (TPC), DPPH free radical scavenging activity and individual phenolic compounds. In addition, sample pH and total soluble solids (TSS) were measured. Results showed that ‘Emma’ berry samples had the highest value of TSS content – 10.5% (°Bx) and the lowest pH value – 3.65. The variety ‘Korsör’ showed the lowest TSS content – 8.1% (°Bx) as well as the lowest TPC and DPPH free radical scavenging activity, the variety ‘Haschberg’ showed the highest pH value. The variety ‘Haidegg 17’ stood out with a high TPC. In total six phenolic compounds were identified and quantified in the analysed samples – gallic acid, catechin, chlorogenic acid, p-coumaric acid, sinapic acid and 3,5-dihydroxybenzoic acid. According to the obtained results, it was evident that the indicators for some parameters differ from the information available in the literature about the composition of berries of crops grown in other regions. This suggests that it is worth further researching elder tree varieties grown in northern climate.

Key words:

DPPH, elderberry, HPLC-PDA, polyphenols, soluble solids

Effect of calcium foliar application on some fruit quality characteristics of ‘Sinap Orlovskij’ apple

J. Lanauskas¹ and N. Kvikliené²

¹Lithuanian Institute of Horticulture, Kauno 30, LT-54333 Babtai, Kaunas distr., Lithuania; e-mail: j.lanauskas@lsdi.lt
²Lithuanian Institute of Horticulture, Kauno 30, LT-54333 Babtai, Kaunas distr., Lithuania;e-mail: n.kvikliene@lsdi.lt

Abstract:

Effect of calcium fertiliser sprays on eight-ten-year-old apple trees of the cv. ‘Sinap Orlovskij’ on rootstock 62-396 was investigated at the Lithuanian Institute of Horticulture in 2001–2003. Calcium chloride, calcium nitrate, liquid experimental calcium fertilisers and Wuxal Calcium were used. Calcium chloride was applied twice at the time close to harvest (total CaO rate – 5.9 kg ha^-1). Other fertilisers were used fivefold from the beginning of June (total CaO rate – 6 kg ha^-1) in the combination of two sprays with calcium chloride (CaO rate – 5.9 kg/ha^-1). The most significant effect of calcium fertilisers on fruit calcium content was found in 2003. When fertilisers were applied sevenfold, fruit calcium increased by 50–120 mg/kg of dry fruit weight in comparison with the control. The most unfavourable for calcium accumulation was the warm and dry weather in year 2002. Apples contained only 170–230 mg of calcium per kg of fruit dry matter and bitter pit affected up to 35% of apples. In years 2001 and 2003 fruit calcium content was 300–330 and 340–460 mg/kg, respectively, bitter pit affected up to 2% of apples. Sevenfold applied calcium fertilisers decreased bitter pit incidence about twice in comparison with the control and two applications of calcium chloride. All tested fertilisers had a similar effect on bitter pit reduction. Calcium fertilisers had not a consistent effect on fruit flesh firmness, soluble solids content and natural weight loss.

Key words: